The effects of moderately raised classroom temperatures and classroom ventilation rate on the performance of schoolwork by children (RP-1257).
Two independent field intervention A procedure used in a lawsuit by which the court allows a third person who was not originally a party to the suit to become a party, by joining with either the plaintiff or the defendant. experiments were carried out in school classrooms in late summer (in 2004 and 2005). The air temperature was manipulated by either operating or idling split cooling units installed for the purpose. In one of these experiments, the outdoor air supply rate was also manipulated. The conditions were established for one week at a time It's now officially Saturday and on 1116SEN it's time for 'One Week At A Time' with your hosts Mark Franklin and Luke Mather.
Currently airing every Saturday evening (7pm til Midnight) 'One Week At A Time' is a revolutionary and fun sports talkback show on SEN 1116 Sports Radio in in a blind crossover Crossover
The point on a stock chart when a security and an indicator intersect. Crossovers are used by technical analysts to aid in forecasting the future movements in the price of a stock. In most technical analysis models, a crossover is a signal to either buy or sell. design with repeated measures on two classes of 10- to 12-year-old children. Six to eight exercises exemplifying ex·em·pli·fy
tr.v. ex·em·pli·fied, ex·em·pli·fy·ing, ex·em·pli·fies
a. To illustrate by example: exemplify an argument.
b. different aspects of schoolwork (numerical numerical
expressed in numbers, i.e. Arabic numerals of 0 to 9 inclusive.
a numerical code is used to indicate the words, or other alphabetical signals, intended. and language-based) were performed as part of normal lessons. Pupils indicated their environmental perceptions and the intensity of any symptoms on visual analogue (electronics) analogue - (US: "analog") A description of a continuously variable signal or a circuit or device designed to handle such signals. The opposite is "discrete" or "digital". scales. Their thermal sensation changed from slightly too warm to neutral, and the performance of two numerical and two language-based tests was significantly improved when the temperature was reduced from 25[degrees]C to 20[degrees]C (77[degrees]F to 68[degrees]F). When the outdoor air supply rate was increased from 5.2 to 9.6 L/s (11.0 to 20.3 cfm) per person, their performance of four numerical exercises improved significantly, confirming the results of previously reported experiments in the same series. The above improvements were mainly in terms of the speed at which tasks were performed, with negligible This article or section is written like a personal reflection or and may require .
Please [ improve this article] by rewriting this article or section in an . effects on error rate. Most school classrooms worldwide experience raised air temperatures during increased thermal loads, e.g., in warm weather; these results show that providing some means of avoiding elevated temperatures would improve educational attainment Educational attainment is a term commonly used by statisticans to refer to the highest degree of education an individual has completed.
The US Census Bureau Glossary defines educational attainment as "the highest level of education completed in terms of the .
Unsuitably high temperatures are common in classrooms, even those in cold countries. For example, a survey of temperatures in a large number of schools in Sweden Sweden, Swed. Sverige, officially Kingdom of Sweden, constitutional monarchy (2005 est. pop. 9,002,000), 173,648 sq mi (449,750 sq km), N Europe, occupying the eastern part of the Scandinavian peninsula. showed that classroom temperatures were generally 23[degrees]C-25[degrees]C (73.4[degrees]F-77[degrees]F) in the shoulder seasons (April to September September: see month. ), 3[degrees]C-6[degrees]C (5[degrees]F-10[degrees]F) above what teachers and pupils preferred. Some classroom temperatures were as high as 30[degrees]C (86[degrees]F), which is quite remarkable for such a cold country (Eriksson The surname Eriksson (also spelled Erikson or Ericsson) is a historically famous Scandinavian appellation. The most famous bearer of this name was Erik the Red, father of Leif Erikson, who found the Americas before Christopher Columbus's supposed discovery; though et al. 1967). The most common reason for such high temperatures is that classroom ventilation ventilation, process of supplying fresh air to an enclosed space and removing from it air contaminated by odors, gases, or smoke.
Proper ventilation requires also that there be a movement or circulation of the air within the space and that the temperature and rates are too low to remove the excess heat load caused by sunshine entering the windows, which until relatively recently were traditionally designed to provide as much daylight as possible, with large glazed glaze
1. A thin smooth shiny coating.
2. A thin glassy coating of ice.
a. A coating of colored, opaque, or transparent material applied to ceramics before firing.
b. areas that faced the sun. This is especially the case in the many schools that have only natural ventilation Natural ventilation is the process of supplying and removing air through an indoor space by natural means. There are two types of natural ventilation occurring in buildings: wind driven ventilation and stack ventilation. , as windows must often remain closed to exclude external noise and prevent draft, but it may also be the case in schools with mechanical ventilation mechanical ventilation
A mode of assisted or controlled ventilation using mechanical devices that cycle automatically to generate airway pressure. and no cooling.
Very few data are available on thermal effects on the performance of schoolwork by children. A recent wide-ranging wide-rang·ing
Covering a wide area; including much: a pianist's wide-ranging repertoire; a wide-ranging interview. and authoritative review of research by Mendell and Heath heath, tract of open land
heath, tract of open land characterized by a few scattered trees, abundant moss cover, and numerous low shrubs, principally of the heath family (see heath, in botany). (2005) of the factors that might influence student performance found only one peer-reviewed study of how the air temperature in classrooms affects schoolchildren's performance (Schoer and Shaffran 1973). These authors reported three experiments in which 10- to 12-year-old pupils in matched pairs were assigned as·sign
tr.v. as·signed, as·sign·ing, as·signs
1. To set apart for a particular purpose; designate: assigned a day for the inspection.
2. either to a classroom without cooling (where the temperature was about 26[degrees]C [78.8[degrees]F]) or to an adjacent air-conditioned air-con·di·tion
tr.v. air-con·di·tioned, air-con·di·tion·ing, air-con·di·tions
To subject to, provide with, or ventilate by air conditioning.
Adj. 1. classroom (where the temperature was about 22.5[degrees]C [72.5[degrees]F]). The classrooms were especially built for the purpose. Each group then worked in the same classroom every school day for six to eight weeks. Nineteen different tests were applied, ranging from very simple and repetitive tests (such as crossing out certain letters in a text) to school exercises stated to be current at the time (such as coding numbers onto machine-readable ma·chine-read·a·ble
Easy to feed directly into a computer, as data that have been stored magnetically.
in a form suitable for processing by a computer punched cards See punch card.
(storage, history) punched card - (Or "punch card") The signature medium of computing's Stone Age, now long obsolete outside of a few legacy systems. ), and the students' performance was significantly better in the classroom that was always cool, on average by 5.7%. However, the subjects knew they were taking part in an experiment (because they were taken by bus each day to the experimental classrooms and instructed by experimenters who were not their normal class teachers) and knew when they were being tested (because each test was performed under maximum effort conditions and timed with a stop-watch), and by talking to Noun 1. talking to - a lengthy rebuke; "a good lecture was my father's idea of discipline"; "the teacher gave him a talking to"
rebuke, reprehension, reprimand, reproof, reproval - an act or expression of criticism and censure; "he had to each other over six to eight weeks, they must have known that there was a difference in temperature between the two classrooms. This means that the observed difference in performance could have been due to a gradual process of discouragement and growing resentment Resentment is an emotion of anger felt as a result of a real or imagined wrong done. Etymologically from "ressentir", French re-, intensive prefix, and sentir "to feel"; from the latin "sentire". The English word has become synonymous with anger and bitterness. between two groups of pupils. This interpretation is supported by the original authors' own analysis showing that the difference in performance between the groups increased over time, while the parallel processes of acclimatization acclimatization
Any of numerous gradual, long-term responses of an individual organism to changes in its environment. The responses are more or less habitual and reversible should conditions revert to an earlier state. , familiarization fa·mil·iar·ize
tr.v. fa·mil·iar·ized, fa·mil·iar·iz·ing, fa·mil·iar·iz·es
1. To make known, recognized, or familiar.
2. To make acquainted with. , and learning would all be expected to reduce over time the negative effects of temperature on performance.
Mendell and Heath (2005) did not review the comprehensive set of experiments on the effects of classroom temperature on the performance of schoolwork that was carried out in the 1960s and 1970s in Sweden, probably because the only report of them in an archival peer-reviewed journal peer-reviewed journal Refereed journal Academia A professional journal that only publishes articles subjected to a rigorous peer validity review process. Cf Throwaway journal. (Wyon Several members of the Wyon family were noted medal makers:
Act of or capacity for grasping with the intellect. The term is most often used in connection with tests of reading skills and language abilities, though other abilities (e.g., mathematical reasoning) may also be examined. , supplying synonyms and antonyms) so that their rate of working and the number of errors they made could be quantified. The children's performance of both types of task was significantly lower at 27[degrees]C and 30[degrees]C (80.6[degrees]F and 86[degrees]F), in comparison to 20[degrees]C (68[degrees]F). In the numerical tasks, the effect was on rate of working, but reading comprehension Reading comprehension can be defined as the level of understanding of a passage or text. For normal reading rates (around 200-220 words per minute) an acceptable level of comprehension is above 75%. as well as reading speed were reduced by raised temperatures. Performance tended to be lower, though not significantly lower, at 27[degrees]C (80.6[degrees]F) than at 30[degrees]C (86[degrees]), and the negative effects of raised classroom temperatures were significant in the afternoon, when the children were fatigued, but not in the morning. The magnitude of the negative effect of temperature on performance was much larger in this study than was found in the study by Schoer and Shaffran (1973), often as great as 30%. The appearance and behavior of the children were systematically observed in these studies from behind one-way one-way
1. Moving or permitting movement in one direction only: a one-way street.
2. Providing for travel in one direction only: a one-way ticket. glass, and both were significantly affected by raised classroom temperature (Holmberg and Wyon 1972): the children became visibly hot but were very slow to adjust their clothing; girls became restless restless,
adj in Chinese medicine, pertaining to either an abundance of heat energy, in conjunction with redness of face or to overstimulation in which case the face will be pale or greenish. but continued to work, while boys began to behave in an undisciplined way and could be seen to concentrate less well. In another experiment in the same series, carried out in a language laboratory rather than a classroom, significant and negative effects of artificially raising the temperature from 20[degrees]C to 27[degrees]C (68[degrees]F to 80.6[degrees]F) could be shown when the children had to listen and speak a word, though not when they were listening and writing (Ryd and Wyon 1970). In a fourth experiment, performed this time in a climate chamber in England England, the largest and most populous portion of the United Kingdom of Great Britain and Northern Ireland (1991 pop. 46,382,050), 50,334 sq mi (130,365 sq km). It is bounded by Wales and the Irish Sea on the west and Scotland on the north. , in which groups of four 12-year-old boys were exposed to 20[degrees]C, 23.5[degrees]C, and 27[degrees]C (68[degrees]F, 74.3[degrees]F, and 80.6[degrees]F) in balanced order, no effects of the intermediate temperature could be shown (Wyon 1969), while the highest temperature caused children to perform schoolwork more slowly and to complete a diagnostic test of cue-utilization (the Tsai-Partington test) more rapidly, indicating that raised temperatures reduce arousal arousal /arous·al/ (ah-rou´z'l)
1. a state of responsiveness to sensory stimulation or excitability.
2. the act or state of waking from or as if from sleep.
3. or alertness.
The results of the studies summarized above suggest that increased classroom temperatures can have negative effects on the performance of schoolwork by children. However, they were all obtained nearly four decades ago, and the results differ in terms of the magnitude of the effects and yield little information on how far below 27[degrees]C (80.6[degrees]F) it is possible to extrapolate extrapolate - extrapolation the findings. Mendell and Heath (2005) concluded that no other studies on this issue have been carried out since then, probably because the main focus of indoor environmental research has been on thermal effects on the performance of office work by adults. This research was recently reviewed by Wyon and Wargocki (2006a), who concluded that thermal discomfort Discomfort may refer to pain, an unpleasant sensation, or to suffering, an unpleasant feeling or emotion. distracts attention and generates complaints, while warmth lowers arousal, exacerbates sick building syndrome sick building syndrome
An illness affecting workers in office buildings, characterized by skin irritations, headache, and respiratory problems, and thought to be caused by indoor pollutants, microorganisms, or inadequate ventilation. (SBS See Small Business Server. ) symptoms, and has a negative effect on mental work. The same effects may also be expected to occur for children and their performance of schoolwork, and children may be more affected by environmental effects even though they typically complain less about them. The present experiments were therefore designed to determine whether avoiding elevated temperatures in classrooms can improve the performance of schoolwork by children, and if so, by how much. In addition, the present experiments investigated the effects of increased outdoor air supply rate on the performance of schoolwork by children as a continuation of two other experiments in the same series, reported in a separate paper by Wargocki and Wyon (2007).
This study was designed as a series of field experiments in existing classrooms occupied by children performing their normal schoolwork. This was more natural for children than transporting them to a laboratory where they might behave abnormally ab·nor·mal
Not typical, usual, or regular; not normal; deviant.
[Alteration (influenced by ab-1) of obsolete anormal, from Medieval Latin , e.g., exert extra effort to perform well. Two experiments in which the air temperature in classrooms was manipulated were performed in the present series, all of them in the same school in Denmark Denmark (dĕn`märk), Dan. Danmark, officially Kingdom of Denmark, kingdom (2005 est. pop. 5,432,000), 16,629 sq mi (43,069 sq km), N Europe. , which is situated in the cool temperate temperate /tem·per·ate/ (tem´per-at) restrained; characterized by moderation; as a temperate bacteriophage, which infects but does not lyse its host.
adj. area of Northern Europe Europe (yr`əp), 6th largest continent, c.4,000,000 sq mi (10,360,000 sq km) including adjacent islands (1992 est. pop. 512,000,000). ; two experiments in which the outdoor air supply rate to classrooms and filter condition were manipulated are reported in another paper (Wargocki and Wyon 2007). The two experiments reported here were both crossover experiments in pairs of classrooms, in which two air temperatures were imposed in the same week, one in each adjacent classroom. The temperature conditions were switched between the classrooms the following week (crossover design). One experiment (Experiment 1T) was a 2 x 2 design in which each air temperature was re-imposed but with a different outdoor air supply rate. In Experiment 2T, the air temperature was changed but the outdoor air supply rate remained constant. Both experiments were performed in late summer in two successive school years, and the supply air filters were always new. Both experiments were performed as repeated-measures designs, i.e., the comparisons between conditions were always within-subject comparisons, to eliminate any bias due to individual differences in the ability to perform schoolwork. The sequence of exposures is shown in Table 1. During the experiments, the teachers and pupils were allowed to open the windows and doors as usual, and no changes in the schedule of normal school activities were made, so as to maintain the teaching environment and routines as normal as possible. The interventions were all improvements to existing conditions and were approved by parents, teachers, the School Board, the responsible local authority, and the Danish Ethics Review Board once this had been satisfactorily explained. Children were not asked for their consent so that they would remain unaware that they were taking part in an experiment in which classroom temperature and ventilation rate were being manipulated.
School, Classrooms, and Ventilation
The school is located in Denmark. It is an elementary public school for children aged 6 to 16 years and is run by the local authority. The school was selected for the experiment partly because it had six identical classrooms, partly also because energy conservation had led to fan speeds being reduced to well below their design level, and partly because large fenestration fenestration /fen·es·tra·tion/ (fen?es-tra´shun)
1. the act of perforating or condition of being perforated.
2. facing south led to large solar heat gains that considerably increase classroom temperatures (Figure 1). The school buildings were constructed in the 1950s and are made of bricks and concrete with large glazed areas; smoking is not allowed. Mechanical ventilation was installed in 1997. The two classrooms used in the present experiments were part of a row of six identical wings opening off the same straight north-south corridor, all with cathedral-height ceilings and large glazed south-facing facades with five openable windows. Each classroom had a floor area of 65 [m.sup.2] (699.7 [ft.sup.2]) and a volume of 187.5 [m.sup.3] (6621.5 [ft.sup.3]). The classrooms have typical school furniture and floors covered with linoleum linoleum (lĭnō`lēəm), resilient floor or wall covering made of burlap, canvas, or felt, surfaced with a composition of wood flour, oxidized linseed oil, gums or other ingredients, and coloring matter. ; outdoor clothing is left on hooks in the corridor, just outside the classrooms. No cooling was available in the classrooms. They are supplied with 100% outdoor air, filtered (F7 class bag filters) and pre-heated from a central air-handling unit (AHU A´hu
n. 1. (Zool.) The Asiatic gazelle. ) situated in the basement This article is about the section of a building. For the foundation, see Basement rock.
A basement is one or more floors of a building that are either completely or partially below the ground floor. Slab-on-grade buildings do not have basements. ; there is a cross-flow plate heat exchanger The plate heat exchanger (PHE) was invented by Dr Richard Seligman in 1923 and revolutionised methods of indirect heating and cooling of fluids.
A plate heat exchanger is a type of heat exchanger that uses metal plates to transfer heat between two fluids. in the AHU for heat recovery. The intermittent intermittent /in·ter·mit·tent/ (-mit´ent) marked by alternating periods of activity and inactivity.
1. Stopping and starting at intervals.
2. operation of the AHU (the system was on nine hours per day and off during weekends and school holidays) is controlled by a computer. Each pair of classrooms in a given experiment was supplied with outdoor air from the same AHU. Pre-existing Adj. 1. pre-existing - existing previously or before something; "variations on pre-existent musical themes"
pre-existent, preexistent, preexisting
antecedent - preceding in time or order vertical brick shafts are used to transport the air from the basement, where the AHU is situated, to the classrooms. Supply air entered each classroom through supply grilles located in the wall above the openable windows and left through exhaust Exhaust may refer to:
To reduce the classroom temperature, wall-mounted split-unit air conditioning air conditioning, mechanical process for controlling the humidity, temperature, cleanliness, and circulation of air in buildings and rooms. Indoor air is conditioned and regulated to maintain the temperature-humidity ratio that is most comfortable and healthful. was installed in each classroom, consisting of an outdoor unit, situated on the roof, connected to two low-noise indoor units installed on the walls perpendicular to the south facade facade (fəsäd`), exterior face or wall of a building. The term implies ordered placement of its openings and other features and thus seems inapplicable to a wall without design. , above the height of the ventilation inlet inlet /in·let/ (-let) a means or route of entrance.
pelvic inlet the upper limit of the pelvic cavity.
thoracic inlet the elliptical opening at the summit of the thorax. grilles. Two indoor units were installed to keep the noise level as low as possible. The maximum capacity of the cooling system cooling system: see air conditioning; internal-combustion engine; refrigeration.
Apparatus used to keep the temperature of a structure or device from exceeding limits imposed by needs of safety and efficiency. was 6 kW, but the units were always operated at low speed to reduce noise (about 25-30 dB(A) per unit according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. their specifications), thus the actual capacity was only 5 kW. The cooling capacity required was estimated by calculating the heat loads from occupants and the sun for the period of the year for which the experiments were scheduled (August-September). The capacity installed was estimated to be sufficient to keep classroom temperature at 20[degrees]C (68[degrees]F) with outdoor temperatures up to 30[degrees]C (86[degrees]F) and windows closed. The fans of the indoor units of the split air-conditioners were operated continuously, independently of whether the cooling was on or off, to create a placebo placebo (pləsē`bō), inert substance given instead of a potent drug. Placebo medications are sometimes prescribed when a drug is not really needed or when one would not be appropriate because they make patients feel well taken care of. condition. The cooling units were operated on the weeks when the temperature was to be reduced according to the study plan. Otherwise the temperature in the classrooms was dependent on the weather conditions. No heating was installed to increase indoor temperatures, to maintain the realism realism, in art
realism, in art, the movement of the mid-19th cent. formed in reaction against the severely academic production of the French school. of each exposure. However, this meant that in this condition the temperature increased during the school day, reaching its maximum in the afternoon. The temperature was fairly constant in the condition with reduced temperature In thermodynamics, the reduced temperature of a fluid means the actual temperature, divided by its critical temperature.
It is often used in thermodynamical formulas, e.g. in the classrooms. Using continuous measurements of temperatures in the classrooms, daily average temperatures were estimated for the periods when children were present in the classrooms, according to their class schedule (short breaks between lessons were excluded). These were then averaged to produce weekly average indoor air temperatures for each classroom, while the standard deviation In statistics, the average amount a number varies from the average number in a series of numbers.
(statistics) standard deviation - (SD) A measure of the range of values in a set of numbers. of the weekly average was calculated from the temperatures measured during a week in the periods when the children were present in the classroom; they are reported in Table 2 in the "Results" section of this paper.
[FIGURE 1 OMITTED]
The AHU was modified for the experiments by fitting a larger fan motor with a frequency controller and by fitting manually controlled dampers that made it possible to more easily rebalance the distribution of supply air between the classrooms; IRIS Iris, in Greek mythology
Iris (ī`rĭs), in Greek mythology, goddess of the rainbow; daughter of Electra and Thaumas. She was often represented as a messenger of Zeus and Hera. dampers were fitted to make it possible to estimate the airflow with an accuracy of [+ or -]7% by measuring the pressure drop with a digital micro-manometer that had an accuracy of [+ or -]1% (Wargocki and Wyon 2007).
The outdoor air supply rate was double-checked using a venturi venturi
a tube with a decrease in the inside diameter that is used to increase the flow velocity of the fluid and thereby cause a pressure drop; used to measure the flow velocity (a venturimeter) or to draw another fluid into the stream. hood with a fan that compensated for pressure drop and a damper damp·er
1. One that deadens, restrains, or depresses: Rain put a damper on our picnic plans.
2. An adjustable plate, as in the flue of a furnace or stove, for controlling the draft. (a method with an accuracy [+ or -]5% of the reading). Prior to the interventions, the outdoor air supply rate to each classroom was determined to be 180 [m.sup.3]/h (105.9 cfm), although the ventilation system ventilation system Public health An air system designed to maintain negative pressure and exhaust air properly, to minimize the spread of TB and other respiratory pathogens in a health care facility was designed for an outdoor air supply rate of 600 [m.sup.3]/h (353.1 cfm) to each classroom to meet the requirements of the Danish Building Regulations (DHBA DHBA D.H. Brown Associates, Inc.
DHBA Deregister Hba 1995) for a classroom occupied by 30 persons. The much lower outdoor air supply rate that was found could have been due to the energy conservation measures that had been implemented some years previously or to small defects in the AHU. The outdoor air supply rate was changed during the experiment by increasing the fan speed and rebalancing Rebalancing
The process of realigning the weightings of one's portfolio of assets.
For example, if your portfolio's proportion of stock has grown too large for your intended assets weightings and risk tolerance, you might rebalance by selling some stock and putting the system. A maximum rate of 800 [m.sup.3]/h (470.9 cfm) (9.7 L/s per person [20.6 cfm/person]) could be achieved. The limiting factors A factor or condition that, either temporarily or permanently, impedes mission accomplishment. Illustrative examples are transportation network deficiencies, lack of in-place facilities, malpositioned forces or materiel, extreme climatic conditions, distance, transit or overflight rights, were the small cross-sectional cross section also cross-sec·tion
a. A section formed by a plane cutting through an object, usually at right angles to an axis.
b. A piece so cut or a graphic representation of such a piece.
2. area of the brick shaft shaft (shaft) a long slender part, such as the diaphysis of a long bone.
1. An elongated rodlike structure, such as the midsection of a long bone.
2. through which the supply air was brought from the basement, the bends in the ducting duct·ing
1. A duct or system of ducts.
2. Material for making ducts. , and the resulting increase in the airflow noise level. The reference outdoor air supply rate was maintained at 180 [m.sup.3]/h (105.9 cfm) (2.2 L/s per person [4.7 cfm/person]). The air supply rates were double-checked each week after rebalancing, using both the hood method HOOD (Hierarchic Object Oriented Design) is a detailed software design method. It is based on hierarchical decomposition of a software problem. It comprises textual and graphical representations of the design. and IRIS dampers with a micro-manometer.
The actual effective ventilation rates in the classrooms were estimated with a general mass balance equation (McIntyre McIntyre, or MacIntyre, is a Scottish surname derived from the Gaelic Mac an t-Saoir literally meaning "Son of the Carpenter".
McIntyre is the name of several places:
1. the pathological diffusion or accumulation in a tissue or cells of substances not normal to it or in amounts in excess of the normal.
2. infiltrate (2). . The error of this method was estimated to be [+ or -]10% (Taylor Taylor, city (1990 pop. 70,811), Wayne co., SE Mich., a suburb of Detroit adjacent to Dearborn; founded 1847 as a township, inc. as a city 1968. A small rural village until World War II, it developed significantly in the second half of the 20th cent. 1997). Theoretical buildup build·up also build-up
1. The act or process of amassing or increasing: a military buildup; a buildup of tension during the strike.
2. of C[O.sub.2] concentration was fitted to the measured buildup by adjusting the assumed air change rate and the assumed production rate of C[O.sub.2] per person, which was allowed to vary between 15 and 20 L/h (0.009-0.012 cfm) as there are few data on the production of C[O.sub.2] by children of this age and the available data suggest that C[O.sub.2] produced by children is similar to what is produced by adults, most probably due to the higher activity level of children (Pejtersen et al. 1991; ECA ECA
See: Export Credit Agency 1992). The number of children in the classroom was obtained from the records kept by the teachers. Minimizing the square-root errors describing the difference between the theoretical and measured buildup of C[O.sub.2] was the criterion for a good fit.
As many estimations as possible were derived for each day, depending on the available C[O.sub.2] data. They were averaged to obtain daily effective ventilation rates. These were then averaged to produce weekly effective ventilation rates for each classroom and used to calculate the standard deviation of the weekly ventilation rate, which is reported in Table 2 in the "Results" section. The standard deviation is stated as an estimate of the uncertainty of the quoted average values because in addition to the instrumental error it includes all the chance factors that will undoubtedly have introduced unexpected variation, such as the door opening, sudden gusts of wind, etc. Such sources of variation would not be included in a conventional uncertainty estimate that was based only on instrumental accuracy. From the measurements of ventilation effectiveness in classrooms with children absent and from continuous measurements of the C[O.sub.2] concentration at two locations in the classrooms with children present (Figure 1), the air in the classrooms was judged to be well mixed.
Silicon-based nondispersive infrared An invisible band of radiation at the lower end of the visible light spectrum. With wavelengths from 750 nm to 1 mm, infrared starts at the end of the microwave spectrum and ends at the beginning of visible light. sensors
1. Of, relating to, or existing as a gas.
2. Full of or containing gas; gassy. C[O.sub.2] (accuracy [+ or -][30 ppm (Pages Per Minute) The measurement of printer speed. See gppm.
PPM - Portable Pixmap + 2% of the reading]) were connected to miniature miniature
much smaller in size than normal animals of the species, but with normal proportions. Animals born prematurely are miniatures but show evidence of prematurity in their haircoat, unerupted teeth and immature hooves. battery-powered Adj. 1. battery-powered - powered by one or more electric batteries; "a battery-powered radio"
powered - (often used in combination) having or using or propelled by means of power or power of a specified kind; "powered flight"; "kerosine-powered jet engines" data loggers data logger - data logging and used to monitor C[O.sub.2] levels every 1-5 minutes in each classroom at a (childproof child·proof
1. Designed to resist tampering by young children: a childproof aspirin bottle.
2. ) height of 2.2 m (7.2 ft) (accuracy of recording the signal from the C[O.sub.2] sensors was [+ or -]1% of full scale). Three similar data loggers were used to monitor temperature (accuracy [+ or -]0.7[degrees]C at 21[degrees]C [[+ or -]1.27[degrees]F at 70[degrees]F]) and relative humidity relative humidity
The ratio of the amount of water vapor in the air at a specific temperature to the maximum amount that the air could hold at that temperature, expressed as a percentage. (accuracy [+ or -]5%RH) continuously in each classroom at a height of 2.2 m (7.2 ft). Similar data loggers were placed in the supply and exhaust ducts of each classroom. State loggers were used to record when any of the windows or the entrance door was open. Those mounted on the doors proved unreliable due to the frequent heavy shock of closing doors; thus, no usable USable is a special idea contest to transfer US American ideas into practice in Germany. USable is initiated by the German Körber-Stiftung (foundation Körber). It is doted with 150,000 Euro and awarded every two years. record of door opening is available. The rate of dust sedimentation sedimentation
In geology, the process of deposition of a solid material from a state of suspension or solution in a fluid (usually air or water). Broadly defined it also includes deposits from glacial ice and materials collected under the effect of gravity alone, as in talus onto horizontal surfaces Noun 1. horizontal surface - a flat surface at right angles to a plumb line; "park the car on the level"
floor, flooring - the inside lower horizontal surface (as of a room, hallway, tent, or other structure); "they needed rugs to cover the bare was measured each week by placing clean glass plates on existing rails or on small brackets brackets: see punctuation. on the walls perpendicular to the windows at a height of 2.2 m (7.2 ft). A surface dust meter was used to assess the percentage of the surface covered by dust at the end of the week. This is accomplished by using forensic Belonging to courts of justice.
forensic 1) adj. from Latin forensis for "belonging to the forum," ancient Rome's site for public debate, and currently meaning pertaining to the courts. gelatin gelatin or animal jelly, foodstuff obtained from connective tissue (found in hoofs, bones, tendons, ligaments, and cartilage) of vertebrate animals by the action of boiling water or dilute acid. tape to lift the dust and then inserting in·sert
tr.v. in·sert·ed, in·sert·ing, in·serts
1. To put or set into, between, or among: inserted the key in the lock. See Synonyms at introduce.
2. the tape into an instrument that measures the amount of light scattered Scattered
Used for listed equity securities. Unconcentrated buy or sell interest. from a laser beam. Spot measurements of airborne airborne /air·borne/ (ar´born) suspended in, transported by, or spread by air.
adj carried through the air. In health care settings, viruses or bacteria may become airborne, e.g. particle density The particle density or true density of a particulate solid or powder, is the density of the particles that make up the powder, in contrast to the bulk density, which measures the average density of a large volume of the powder in a specific medium (usually air). were made for 20 minutes at the end of each week, after the children had left the classroom, using a dust monitor; the size ranges that could be assessed were > 0.75, > 1, > 2, > 3.5, > 5, > 7.5, > 10, and > 15 [micro]m (sensitivity 1 particle/L and reproducibility reproducibility Lab medicine The degree of agreement among repeated measurements of a particular parameter, presented in terms of a standard deviation or coefficient of variation of the results in a set of measurements [+ or -]2%). An ultrafine particle counter A particle counter is an instrument that detects and counts particles. Applications of particle counters are separated into two primary categories:
tr.v. cal·i·brat·ed, cal·i·brat·ing, cal·i·brates
1. To check, adjust, or determine by comparison with a standard (the graduations of a quantitative measuring instrument): before use. Weather data for the whole period were registered.
Measurements of Performance
Each week, in appropriate lessons, the children's usual teachers administered parallel versions of language-based and numerical performance tasks representing different aspects of schoolwork, from reading to mathematics. The presentation of tasks was distributed fairly evenly over the whole week, and the teachers were asked to apply the same task always on the same weekday. No more than one task was performed during one lesson, and generally no more than two to three tasks were performed per day. The tasks were selected so that they could be a natural part of an ordinary school day. They included: (1) addition--the pupils added two four-digit numbers; (2) multiplication--the pupils multiplied mul·ti·ply 1
v. mul·ti·plied, mul·ti·ply·ing, mul·ti·plies
1. To increase the amount, number, or degree of.
2. Mathematics To perform multiplication on. two-digit numbers by three-digit numbers; (3) subtraction--the pupils subtracted two four-digit numbers; (4) number comparison--the pupils checked columns of two seven-digit numbers against each other, the numbers being made similar or different by rotating ro·tate
v. ro·tat·ed, ro·tat·ing, ro·tates
1. To turn around on an axis or center.
2. three of the digits in the middle; (5) logical thinking (i.e., grammatical gram·mat·i·cal
1. Of or relating to grammar.
2. Conforming to the rules of grammar: a grammatical sentence. reasoning)--the pupils categorized cat·e·go·rize
tr.v. cat·e·go·rized, cat·e·go·riz·ing, cat·e·go·riz·es
To put into a category or categories; classify.
cat statements describing the order of the letter pairs AB and BA as True or False (Baddeley Baddeley (or Baddely) is a surname, and may refer to:
a·cous·tic or a·cous·ti·cal
Of or relating to sound, the sense of hearing, or the perception of sound. proofreading--while listening to a recorded voice reading a text aloud, the pupils read the text, marking the inserted in·sert
tr.v. in·sert·ed, in·sert·ing, in·serts
1. To put or set into, between, or among: inserted the key in the lock. See Synonyms at introduce.
2. errors (10 errors were inserted per page of the transcript A generic term for any kind of copy, particularly an official or certified representation of the record of what took place in a court during a trial or other legal proceeding.
A transcript of record in such a way that they could not be found without listening and reading simultaneously); (7) reading and comprehension--the pupils read text with choice points inserted (to determine whether the children understood the text, they had to mark one of three different words at each choice-point; all three words were correct in the immediate context of the phrase into which they had been inserted, but only one was correct in the context of the whole text); and (8) proofreading--the pupils read a prepared text in which four different kinds of errors had been inserted: spelling SPELLING, The art of putting the proper letters in words.
2. It is a rule that when it appears with certainty what is meant, bad spelling will not avoid a contract; for example, where a man agreed to pay thirty pounds, he was held bound to pay thirty pounds; errors, two kinds of grammatical errors (one obvious in the context of the phrase in which it occurs and one correct in this context but incorrect in the wider context of the preceding text), and logical errors. Following complaints by some parents that the children were being "tested unusually often," Tasks 2, 4, and 8 were omitted in the second experiment.
The tasks were specially developed so that their difficulty was appropriate to the age of the children, in consultation with the class teachers. In developing these tasks, the aim was that they should resemble standard teaching material as closely as possible. The mathematical calculations were familiar to the children, but the form of the other tasks was new to them. The teachers taught the children how to perform the tasks by working through examples with the class to make sure that the children understood each task. The duration of the tasks was short enough to ensure that children could not complete them in the time available. Up to 10 minutes were allocated for each task, except in the case of acoustic proofreading Proofreading traditionally means reading a proof copy of a text in order to detect and correct any errors. Modern proofreading often requires reading copy at earlier stages as well. , where sometimes up to 16 minutes were used. If any of the pupils completed the tasks before the allocated time, all other pupils were immediately told by the teacher to stop working, and the actual time that had been available for performing the task was noted. Different versions of each test were prepared and versions were confounded with occasions (i.e., first to fourth week). Performance was measured in terms of speed (how quickly each pupil pupil: see eye. worked per unit time) and errors (the percentage of errors that were committed); in the case of proofreading, false positives were also recorded. In the case of acoustic proofreading, only the errors and false positives were recorded because the speed of performance was imposed by the rate at which the text was dictated dic·tate
v. dic·tat·ed, dic·tat·ing, dic·tates
1. To say or read aloud to be recorded or written by another: dictate a letter.
a. . The children's performance was first analyzed an·a·lyze
tr.v. an·a·lyzed, an·a·lyz·ing, an·a·lyz·es
1. To examine methodically by separating into parts and studying their interrelations.
2. Chemistry To make a chemical analysis of.
3. using a complete design analysis, i.e., analyzing for each exercise only the results obtained from those pupils who had taken that test in all conditions and then repeating the analysis using all available data, i.e., including the performance of pupils who had not performed the exercise in all conditions (incomplete design). If performance differed significantly between occasions, disregarding dis·re·gard
tr.v. dis·re·gard·ed, dis·re·gard·ing, dis·re·gards
1. To pay no attention or heed to; ignore.
2. To treat without proper respect or attentiveness.
n. the interventions--perhaps due to learning, increased familiarity with the exercise, fatigue fatigue, in engineering
fatigue, in engineering, microscopic cracking of materials, especially metals, after repeated applications of stress. Fissures may be formed within pieces of metal during their manufacture when, while cooling from the molten state, , or differences between test versions--the analyses were repeated after adjusting the results for this effect. The adjustment was made by multiplying mul·ti·ply 1
v. mul·ti·plied, mul·ti·ply·ing, mul·ti·plies
1. To increase the amount, number, or degree of.
2. Mathematics To perform multiplication on. the individual performance of each pupil on a given task in that week by a coefficient coefficient /co·ef·fi·cient/ (ko?ah-fish´int)
1. an expression of the change or effect produced by variation in certain factors, or of the ratio between two different quantities.
2. calculated as the ratio of the average performance of that pupil's class on that task in the first week this task was introduced to the class by the average performance of the pupil's class on that task in that week.
Measurements of Perceptions and Symptoms
The children marked visual analogue (VA) scales each week during the last lesson each Friday Friday: see Sabbath; week.
young Indian rescued by Crusoe and kept as servant and companion. [Br. Lit.: Robinson Crusoe]
See : Servant to indicate the intensity of various SBS symptoms and their perceptions of the environment. Each scale was a 100 mm (3.9 in.) horizontal line (Descriptive Geometry & Drawing) a constructive line, either drawn or imagined, which passes through the point of sight, and is the chief line in the projection upon which all verticals are fixed, and upon which all vanishing points are found.
See also: Horizontal with end-labels describing the perception or symptom symptom /symp·tom/ (simp´tom) any subjective evidence of disease or of a patient's condition, i.e., such evidence as perceived by the patient; a change in a patient's condition indicative of some bodily or mental state. intensity (Figure 2). The distance of the mark from one end of the scale was recorded in millimeters (0-100). The items on the VA scales included the following: the perception of classroom temperature, air movement, air dryness, air freshness, illuminance illuminance: see photometry.
A term expressing the density of luminous flux incident on a surface. This word has been proposed by the Colorimetry Committee of the Optical Society of America to replace the term illumination. and noise, and the symptoms of nose congestion The condition of a network when there is not enough bandwidth to support the current traffic load.
congestion - When the offered load of a data communication path exceeds the capacity. , throat, lip lip (lip)
1. the upper or lower fleshy margin of the mouth.
2. any liplike part; labium.
cleft lip a congenital cleft or defect in the upper lip. , and skin dryness, eyes hurting, hunger Hunger
A term most commonly used to refer to the subjective feelings that accompany the need for food; however, the study of this topic has come to include consideration of the overall control of food intake. , fatigue, sleepiness sleepiness Drowsiness, somnolence Sleep disorders Difficulty in maintaining the wakeful state so that the person falls asleep if not actively kept aroused; sleepiness is not simply physical tiredness or listlessness. See Excessive daytime sleepiness. , and headache headache
Pain in the upper portion of the head. Episodic tension headaches are the most common, usually causing mild to moderate pain on both sides. They result from sustained contraction of face and neck muscles, often due to fatigue, stress, or frustration. . The students also indicated whether they had slept badly or too little the preceding night and whether they felt like working on the day the VA scale was marked. The VA scales were administered by the teachers, who, by going through examples, also taught the children how to use them. This was done to make sure that the children understood how to use the scales. As in the analysis of performance, the results obtained on the VA scales were first analyzed using complete design analyses, i.e., each scale was first analyzed using only the results of those pupils who had marked that scale in all conditions, and then using the ratings of all pupils, including results from those who had not marked this scale in all conditions (incomplete design).
[FIGURE 2 OMITTED]
Observational Checklists and Parental Logbooks
Each week the teachers carried out checklist observation of the children's behavior. The list included the following items (Wyon and Holmberg 1972): working very hard, looking around, closing eyes, playing with things, happy, apathetic ap·a·thet·ic
Lacking interest or concern; indifferent.
apa·thet , rocking the chair, disobedient, making too much noise, talking to a neighbor, teasing teasing
the act of parading a male before a female to see if she displays estrus, and is therefore in a state where mating is likely to be fertile. others, looking pale, supporting head with hands, and coughing/sneezing. The list was marked while pupils performed one of the tasks. For each item on the list, the number of different pupils noted by the teachers as exhibiting this behavior was counted and then grouped by condition and teacher. Parents and teachers recorded their observations of children's health Children's Health Definition
Children's health encompasses the physical, mental, emotional, and social well-being of children from infancy through adolescence. , mood, and changes in behavior in logbooks. They were asked to complete the logbook every day during the experiments. In addition, the teachers recorded in their logbooks the time when each task had been applied and its duration.
Measurements of Perceived per·ceive
tr.v. per·ceived, per·ceiv·ing, per·ceives
1. To become aware of directly through any of the senses, especially sight or hearing.
2. To achieve understanding of; apprehend. Air Quality
A sensory sensory /sen·so·ry/ (sen´sor-e) pertaining to sensation.
1. Of or relating to the senses or sensation.
2. panel of adults was recruited to assess the air quality in the classrooms after the pupils had gone home, so as to not disturb normal school activities. The measurements were made once a week, in the afternoon, about 1-1.5 hours after the pupils had left the classrooms. The panel entered the classrooms every 2-3 minutes in groups of two to three at a time and assessed the air quality immediately upon entering; the doors were closed during these assessments and the order of assessments was balanced. Between assessments the panel members stayed in a well-ventilated rear entrance hall to the school, opening off the corridor leading to the classrooms. Subjects assessed air quality using four scales: continuous acceptability scale (Wargocki 2004), odor odor (o´der) a volatile emanation perceived by the sense of smell.
1. The property or quality of a thing that affects, stimulates, or is perceived by the sense of smell. intensity (Yaglou et al. 1936), and two horizontal VA scales describing the freshness and dryness of classroom air. The ratings from the scales were digitized using the following coding: clearly acceptable = 1, clearly not acceptable = -1; no odor = 0, overpowering o·ver·pow·er·ing
So strong as to be overwhelming: an overpowering need for solitude.
o odor = 50; endpoints on VA scales were coded 0 and 100. The sensory panel approach was used only in Experiment 2T.
A commercially available statistical software package was used to analyze an·a·lyze
1. To examine methodically by separating into parts and studying their interrelations.
2. To separate a chemical substance into its constituent elements to determine their nature or proportions.
3. the data. Shapiro-Wilk's test was used to test whether residuals Residuals
(1) Part of stock returns not explained by the explanatory variable (the market index return). Residuals measure the impact of firm-specific events during a particular period. were normally distributed, and if necessary the data were log transformed. When the normality normality, in chemistry: see concentration. assumption was fulfilled ful·fill also ful·fil
tr.v. ful·filled, ful·fill·ing, ful·fills also ful·fils
1. To bring into actuality; effect: fulfilled their promises.
2. , repeated measures 2 x 2 analysis of variance The discrepancy between what a party to a lawsuit alleges will be proved in pleadings and what the party actually proves at trial.
In Zoning law, an official permit to use property in a manner that departs from the way in which other property in the same locality (ANOVA anova
see analysis of variance.
ANOVA Analysis of variance, see there ) were performed for pupils for whom data from all four conditions were available. A general linear model (GLM GLM Global Language Monitor
GLM Global Marine (stock symbol)
GLM Graduated Length Method (ski instruction)
GLM Good Looking Mom (used in pediatric practices)
GLM God Loves Me ) with Type V sum of squares was also used for all available data, i.e., including data from pupils for whom no data were available in some conditions. Friedman's two-way nonparametric nonparametric
said of statistical techniques which do not depend on the data having a normal or some other definable distribution. ANOVA was used when the normality assumption was not met, for the markings on VA scales, and when analyzing the observational checklists. Wilcoxon's matched-pairs signed-ranks test was used to analyze the main effects of ventilation and temperature when the assumption of normality was not valid: performance and ratings on VA scales were averaged for one condition independently of the other one to form pairs of observations separately for each pupil, as is the case in 2 x 2 ANOVA. The averaging was carried out accepting only those pupils for whom ratings were available in all the conditions tested and then repeated accepting all ratings. The Wilcoxon test Wilcoxon test
a test used in statistics to compare paired data. Has the advantage of incorporating the size of the difference between the two sets of data in the comparison. was always used to test differences between conditions in Experiment 2T. In all statistical tests, the changes in responses were analyzed at the individual level, i.e., using pupils (subjects) as their own controls. The P-level for rejection of the null hypothesis null hypothesis,
n theoretical assumption that a given therapy will have results not statistically different from another treatment.
n was set to 0.05 (2-tail), meaning that in 100 tests only 5 would appear to be significant by chance.
In Experiment 1T, the temperature was reduced and the ventilation rate was altered in a 2 x 2 design balanced for order of presentation. Table 2 shows the results of continuous measurements of temperature, relative humidity, C[O.sub.2], and window opening behavior in the classrooms in the course of the experiment. The values shown describe the periods when children were present in the classrooms (excluding even short breaks between classes). Table 2 shows that the air temperature in the classrooms was about 20[degrees]C (68[degrees]F) when cooling was provided and 23.6[degrees]C (74.5[degrees]F) in the warmer reference condition, so that the difference was 3.6 K (6.5[degrees]F). Average maximum temperatures in the two conditions differed by 3.9 K (7.0[degrees]F). Due to lower than normal outdoor air temperatures and opening of windows, the high temperature in the classrooms with high outdoor air supply rate was lower than expected. The effective ventilation rate estimated from measurements of C[O.sub.2] by using a mass balance equation was about 5 L/s per person (10.6 cfm/person) and 9.5 L/s per person (20.1 cfm/person) at the two outdoor air supply rates. The relative humidity was about 50%-55%, higher at lower air temperature, as expected. The windows were opened more often at the higher temperature, as might be expected; C[O.sub.2] was higher at the low ventilation rate, as expected. Spot measurements in empty classrooms without children showed that the air velocity was slightly higher at the low temperature, although it was still low (< 0.11 m/s [22 fpm]); noise levels did not differ much between conditions (Table 3). There are too few data to interpret the measured concentrations of airborne particles <onlyinclude> This is a list of particles in particle physics, including currently known and hypothetical elementary particles, as well as the composite particles that can be built up from them. , but the few measurements performed suggest that they were lower at the high ventilation rate (Table 3). The outdoor ozone ozone (ō`zōn), an allotropic form of the chemical element oxygen (see allotropy). Pure ozone is an unstable, faintly bluish gas with a characteristic fresh, penetrating odor. The gas has a density of 2.144 grams per liter at STP. concentration was about 24[+ or -]6 ppb ppb
parts per billion during the course of experiments.
The results of the schoolwork performance exercises are presented in Table 4. They are based on complete design analyses, i.e., analyzing for each exercise only the results obtained from those pupils who had taken that test in all four conditions. A detailed summary of the analyses performed for each test is given in the following text and in Table 5. Due to teacher error, the subtraction subtraction, fundamental operation of arithmetic; the inverse of addition. If a and b are real numbers (see number), then the number a−b is that number (called the difference) which when added to b (the subtractor) equals , multiplication, number checking, and addition tasks were not administered in week three in one class, so using repeated measures in a complete 2 x 2 design was not possible for these exercises. The analysis for the differences between three other conditions, excluding the one from week three, was possible, but since the design of the study does not make it possible to test the differences between single conditions (because they are confounded with any differences between weeks), the analyses of the main effects for these exercises were consequently based instead on an incomplete design, i.e., including the performance of pupils who had not performed the exercise in all four conditions (a complete class in one condition). As a measure of the average performance, adjusted (least squares) means were used.
Subtraction. Analysis of the data for pupils who performed the test in three conditions (complete design) showed that there was a significant difference between conditions (P < 0.001) regarding speed (number of units attempted) but not errors. The analyses based on an incomplete design showed that reducing temperature and increasing outdoor air supply rate significantly improved the speed with which pupils subtracted the numbers. There was also a tendency (P = 0.06) for the increased ventilation rate to reduce the percentage of errors. There was no effect of temperature on percentage errors. Speed significantly increased in the course of the experiment, but no adjustment for this learning effect could be made because of the missing data.
Multiplication. Analysis of the data for pupils who performed the test in three conditions (complete design) showed that there was a significant difference between conditions (P < 0.001) regarding speed (number of units attempted) but not errors. The analyses based on the incomplete design showed that increasing outdoor air supply rate significantly increased speed and reduced percentage errors. There were no significant effects of reduced temperature. Speed and percentage errors decreased significantly in the course of the experiment, but no adjustment for these effects could be made because of the missing data.
Number comparison. Analysis of the data for pupils who performed the test in three conditions (complete design) showed that there was a significant difference between conditions (P < 0.01) regarding speed (the number of units attempted to compare) but not errors. The analyses based on incomplete design showed that increasing the outdoor air supply rate significantly improved the speed with which pupils compared the numbers. There was a tendency for the reduced temperature to increase speed, but this effect did not reach formal statistical significance (P = 0.10). There were no significant effects on errors. Speed and percentage errors significantly increased in the course of the experiment, but no adjustment for these effects could be made because of the missing data.
Addition. Analysis of the data for pupils who performed the task in three conditions (complete design) showed that there was a significant difference between conditions (P < 0.005) regarding speed (the number of units attempted) but not errors. The analyses based on the incomplete design showed that increasing outdoor air supply rate and reducing air temperature significantly improved the speed at which pupils added numbers. There were no significant effects on errors and no significant change of speed or percentage errors in the course of the experiment.
Logical thinking. No significant effects were observed.
Acoustic proofreading. Reducing temperature significantly reduced the error rate. There were no significant effects on false positives. In the course of the experiment, errors increased while the percentage of false positives decreased significantly. Adjusting for these trends did not change the results. There were no effects of increased ventilation rate. Analyses of all available data (incomplete design) showed similar results.
Reading and comprehension. Reducing temperature significantly increased reading speed. There were no effects of increased ventilation on speed or on errors (comprehension). In the course of the experiment, reading speed increased significantly while errors decreased significantly. Adjusting for these trends did not change the results. Analyses of all available data (incomplete design) showed similar results.
Proofreading. The exercise was not completed by either class in week two and, consequently, due to missing data, the effects on either speed or percentage errors/percentage false positives could not be estimated.
The effects on the performance of individual tasks caused by reducing classroom temperature (independent of ventilation) are summarized in Figure 3, while those caused by increasing the outdoor air supply rate (independently of classroom temperature) are summarized in Figure 4. Reduced temperature significantly improved the speed at which the addition, subtraction, and reading and comprehension tasks were performed and significantly reduced the percentage of errors in the acoustic proofreading task. Increased outdoor air supply rate significantly improved the speed at which all four numerical tasks were performed and at the same time reduced the percentage of errors committed in the subtraction and multiplication tasks. Taking into account the number of statistical tests performed, only two of these effects could have occurred by chance at the selected significance level of P = 0.05. It should be noted that the effects on the performance of numerical tasks and the proofreading task were derived from the incomplete data set (one or two classes missing one experimental condition). Thus, although the effects on speed were adjusted, no adjustment was possible for the effects on errors, so the results for errors should be interpreted with caution.
[FIGURE 3 OMITTED]
Observations of the children's behavior, appearance, and working ability. When the temperature was low, independently of ventilation rate, more children were observed to play with things (P = 0.03; total observations = 24). When the outdoor air supply rate was increased, independently of the temperature, more children were observed to talk to neighbors (P = 0.03; total observations = 18). The observations of other items on the checklist were either not significantly different, were too few for it to be possible to make any sound comparisons, or were not made at all. It was not possible to analyze the parental logbooks, as the response rate was too low (35%).
Subjective subjective /sub·jec·tive/ (sub-jek´tiv) pertaining to or perceived only by the affected individual; not perceptible to the senses of another person.
1. assessments. Table 6 shows the results obtained on the VA scales. They are based on complete design analyses, i.e., each scale is analyzed using only the results of those pupils who had marked that scale in all four conditions. When the temperature was reduced, the pupils indicated that it was significantly less warm and more drafty draft·y
adj. draft·i·er, draft·i·est
Having or exposed to drafts of air.
drafti·ly adv. , that there was less light in the classroom, and that the air was significantly more fresh. There was a tendency for the pupils to report that they were more hungry at the lower temperature, but the effect remained not significant (P = 0.059, N = 48) even when data from pupils who had not marked this scale in all four conditions were included. Pupils also indicated that the air was less dry when the temperature was reduced; this effect became formally significant (P = 0.027, N = 48) when data from pupils who had not marked this scale in all four conditions were included. When the ventilation rate was increased, pupils reported that it was significantly less quiet in the classroom. No significant effects on any other VA scale were found.
Estimated thermal state of the children. Table 7 shows the assessments of thermal conditions made by the children on VA scales at the end of the week and the estimated predicted mean vote (PMV See Private market value. ) and predicted percentage dissatisfied dis·sat·is·fied
Feeling or exhibiting a lack of contentment or satisfaction.
dis·satis·fied (PPD (1) (Parallel Presence Detect) The method used by earlier SIMM memory modules to communicate their capacity to the computer. A binary number coming from a parallel set of pins was read by the system, with each pin representing one bit. Contrast with SPD. ) (ASHRAE ASHRAE American Society of Heating, Refrigerating & Air Conditioning Engineers 2004; Fanger 1970; ISO (1) See ISO speed.
(2) (International Organization for Standardization, Geneva, Switzerland, www.iso.ch) An organization that sets international standards, founded in 1946. The U.S. member body is ANSI. 2005). PMV and PPD were estimated using the measured air temperatures, relative humidity, and air velocity (Tables 1 and 2), and it was assumed that the operative temperature was equal to the air temperature, that the clothing insulation insulation (ĭn'səlā`shən, ĭn'sy–), use of materials or devices to inhibit or prevent the conduction of heat or of electricity. was about 0.6 clo and was similar under each experimental condition, and that the metabolic rate Noun 1. metabolic rate - rate of metabolism; the amount of energy expended in a give period
basal metabolic rate, BMR - the rate at which heat is produced by an individual in a resting state of children was about 1.7 met (CEN CEN - Conseil Européen pour la Normalisation.
A body coordinating standardisation activities in the EEC and EFTA countries. 1998; ECA 1992; Pejtersen et al. 1991). A higher metabolic rate was assumed than is usually used for adults during light office work, as it is expected that children in schools have a higher average activity level than adults in offices (running and playing every hour during the breaks between lessons) and because the production rate of C[O.sub.2] by children in the present experiments was similar to what is produced by adults (Table 1). For that reason, the metabolic rate for the children was estimated to be about 40% higher than for adults in offices considering that the body size of an average 10- to 12-year-old child is about 40% smaller than that of an average adult. Table 7 shows that at the higher temperature pupils indicated that it was only slightly too warm, while at the lower temperature they voted close to the midpoint mid·point
1. Mathematics The point of a line segment or curvilinear arc that divides it into two parts of the same length.
2. A position midway between two extremes. of the scale, indicating that it was neither too warm nor too cold. These assessments are supported by the estimated PMV values.
Sensory panel assessments. No sensory assessments were made.
[FIGURE 4 OMITTED]
In Experiment 2T, the temperature was changed in a crossover design while the ventilation rate remained always at its normal low level. Table 2 shows the results of continuous measurements of temperature, relative humidity, C[O.sub.2] level, and window opening behavior in the classrooms throughout the course of the experiment. The values shown describe the periods when children were present in the classrooms (excluding even short breaks between classes). Table 2 shows that the air temperature in the classrooms was 21.6[degrees]C (70.9[degrees]F) in the low temperature condition and 24.9[degrees]C (76.8[degrees]F) in the high temperature condition, i.e., a 3.3 K difference (5.9[degrees]F); a similar but slightly lower difference of 2.3 K (4.1[degrees]F) was observed between the average maximum temperatures measured. The effective ventilation rate estimated from measurements of C[O.sub.2] by using a mass balance equation was about 3 L/s (6.4 cfm) per person; it was slightly higher in the warmer reference condition since the windows were opened more often, as might be expected. The relative humidity was about 52%. The C[O.sub.2] level was slightly higher in the warmer reference condition. Spot measurements in empty classrooms without children showed that the air velocity was slightly higher in the low temperature condition, although it was still low (< 0.15 m/s [29 fpm]); noise levels did not differ between conditions (Table 3). Measurements of settled dust indicate that more dust settled on glass plates when the temperature was low, although the measured concentration of airborne particles was lower in this condition (Table 3). The outdoor ozone concentration was about 18[+ or -]5 ppb during the experiments.
The results of the performance exercises are presented in Table 4. They are based on complete design analyses, i.e., each exercise was analyzed using only the results from those pupils who had performed that exercise in both conditions. A detailed summary of the results obtained for each exercise is given in the following text and in Table 5.
Subtraction. Reduced temperature tended to increase speed (number of units attempted) and to reduce errors. Speed significantly increased throughout the course of the experiment, although errors did not. After adjustment for this learning effect, reduced temperature significantly increased the number of units attempted (P = 0.001). These analyses were supplemented with analyses of all available data, i.e., including the performance of pupils who had not performed the exercise in both conditions (incomplete design); similar results were obtained.
Addition. Reduced temperature significantly increased speed (number of units attempted) with no significant effect on percentage errors. Speed did not increase significantly in the course of the experiment, but percentage errors tended to increase (P = 0.06). After adjustment for this trend, the effect of temperature on errors remained nonsignificant non·sig·nif·i·cant
1. Not significant.
2. Having, producing, or being a value obtained from a statistical test that lies within the limits for being of random occurrence. . The analyses of all available data (incomplete design) showed similar results.
Logical thinking. There was no significant effect of reduced temperature on speed or percentage errors, although both increased significantly throughout the course of the experiment. After adjustment for these trends, the effect of temperature on both speed and errors remained nonsignificant. The analyses of all available data (incomplete design) showed similar results.
Acoustic proofreading. There was no significant effect of reduced temperature on errors, but the percentage of false positives significantly increased at reduced temperature. Neither percentage errors nor the percentage of false positives changed significantly throughout the course of the experiment.
Reading and comprehension. There was no significant effect of reduced temperature on reading speed or errors (comprehension). Speed increased significantly throughout the course of the experiment, while percentage errors decreased significantly. After adjustment for these trends, the effect of temperature on both speed and errors remained nonsignificant. The analyses of all available data (incomplete design) showed similar results.
The effects on the performance of the different tasks that were caused by reducing classroom temperature are summarized in Figure 3. Reduced temperature significantly improved the speed at which the addition task was performed, and the positive effect on speed of subtraction approached significance. Reduced temperature significantly increased the percentage of false positives in the acoustic proofreading task. Taking into account the number of statistical tests performed, one such effect could have occurred by chance at the selected significance level of P = 0.05.
Observations of the children's behavior, appearance, and working ability. When the temperature was reduced, more children were observed to work hard (P = 0.005; total observations = 52). For other items on the checklist, there were either no significant differences or they were indicated too seldom for it to be possible to make any sound comparisons, or they were not indicated at all. Parents were not asked to maintain logbooks in this experiment.
Subjective assessments. Table 6 shows the results obtained on the VA scales. They are based on complete design analyses, i.e., each scale was analyzed using only data from those pupils who had marked that scale in both conditions; it was not possible to perform any analyses that included the ratings of pupils who had not marked some scales in all conditions. When the temperature was reduced, the pupils indicated they felt significantly less warm and also considered that there was significantly less light and noise in the classroom. They reported significantly less intense headaches at reduced temperature. Additionally, there was a tendency for pupils to feel less hungry when the temperature was reduced (P = 0.07). As this nonsignificant tendency is in the opposite direction to the nonsignificant tendency that was found in Experiment 1T, it seems justifiable jus·ti·fi·a·ble
Having sufficient grounds for justification; possible to justify: justifiable resentment.
jus to disregard both of them. No other significant effects were observed.
Estimated thermal state of the children. Table 7 shows the assessments of thermal conditions made by children on the VA scales at the end of the week and the PMV and PPD as estimated for Experiment 1T. Table 7 shows that at the higher temperature pupils indicated that it was only slightly too warm, while at the lower temperature they voted close to the midpoint of the scale, indicating that it was neither too warm or too cold. These assessments are supported by the estimated PMV values.
Sensory panel assessments. Table 8 shows the results of assessments of perceived air quality made by the panel of adult subjects. Reducing air temperature significantly increased the acceptability of classroom air quality; the air was also perceived to be significantly fresher. No other significant effects were observed.
The present results show that reducing the air temperature in classrooms with moderately elevated temperatures improved the performance of schoolwork by children. Performance improved both in the case of numerical tasks requiring concentration and logical thinking and in the case of language-based tasks. The speed at which the tasks were performed improved, and the effects in four cases reached statistical significance (P < 0.05), while in two cases they approached significance (P < 0.10). The percentage of errors was significantly affected in only two cases and only in the acoustic proofreading task, in which the speed of performance was imposed by the rate of dictation. The percentage of errors was reduced in Experiment 1T and the percentage of false positives increased in Experiment 2T, suggesting the exertion exertion,
n vigorous action, a great effort, a strong influence. of increased effort to maintain speed. At the same time, in the latter experiment, the decrease in the percentage of errors committed in subtraction approached significance and pupils reported a significantly reduced intensity of headaches, suggesting that they found it easier to perform the tasks.
The effects on speed in Experiment 2T were similar to the effects observed in Experiment 1T, although only in the case of addition and subtraction were the effects significant in both experiments. This can be considered a fairly good agreement between the two independent experiments carried out one year apart. Further validation See validate.
validation - The stage in the software life-cycle at the end of the development process where software is evaluated to ensure that it complies with the requirements. is required to examine whether the different component skills that affect the overall performance of schoolwork are similarly affected by avoiding elevated temperatures. The present results both confirm and supplement the findings of thermal effects on children's schoolwork performance that were obtained nearly four decades ago in the experiments by Schoer and Shaffran (1973) and by Wyon (1970), who, as in the present experiments, studied thermal effects on school performance in the moderate temperature range. It would be interesting in future studies to examine the effects on performance outside this temperature range and to study whether the magnitude of the effects on performance approaches what was observed in the present study (Figure 3) and by Wyon (1970) or is as low as was reported by Schoer and Shaffran (1973).
Increasing the outdoor air supply rate improved the performance of schoolwork by children. As in the case of the effects of cooling, the effects were mainly on speed and only to a very small extent on errors. The speed at which all four numerical tasks were performed was significantly improved, although no effects could be shown on the language-based tasks. In the previous two experiments in this series (Wargocki and Wyon 2007), similar effects were observed, although in the previous experiments the speed at which the language-based tasks were performed was also improved. Only in the case of subtraction and multiplication did the improvement in speed reach statistical significance in both previous and present experiments (Figure 4). No effects on errors were observed in the previous experiments (Wargocki and Wyon 2007), while in the present study the percentage of errors in multiplication and subtraction was lower when the ventilation rate had been increased. However, these effects were not adjusted for the incomplete data set from which they were derived, due to analytical analytical, analytic
pertaining to or emanating from analysis.
control of confounding by analysis of the results of a trial or test. limitations, and may be considered less credible. Taking the above into account, the present findings provide satisfactory validation of the previous findings, considering that the three experiments were performed at intervals coming or happening with intervals between; now and then.
See also: Interval of several months over the course of a full year, one in winter and two in late summer, with six different groups of children as subjects. Whether the small discrepancies between the results of the three series of experiments are caused by the differences in the effects of outdoor air supply rate on the different component skills that affect the overall performance of schoolwork or by other factors should be investigated in future experiments.
The present results were obtained using a crossover design in pairs of classrooms. The main advantage of this is that any external factors that affect performance in a given week affect the results obtained under both of the conditions that were established in that week, avoiding bias. However, the present design has some limitations; e.g., it does not prevent carryover carryover n. in taxation accounting, using a tax year's deductions, business losses or credits to apply to the following year's tax return to reduce the tax liability. (See: carryback) effects, if present, and is sensitive to differences in group size. To minimize the former, the conditions were changed during each weekend, allowing two days for "recovery." It was not possible to assign an equal number of pupils to each class; however, the small differences in the number of pupils in the classrooms (Table 4) are not expected to have had much effect on the present results. It should be emphasized that testing the effects of interventions on performance separately for each class is not possible in the present design, as the effects of the environmental conditions are confounded with any difference between weeks, such as a systematic change in the performance of some tasks in the course of the experiment (due to learning, familiarity, or boredom Boredom
See also Futility.
Aldegonde, Lord St.
bored nobleman, empty of pursuits. [Br. Lit.: Lothair]
(1821–1867) French poet whose dissipated lifestyle led to inner despair. [Fr. Lit. ) with uncontrolled external factors such as the weather and with differences between the test versions used on different occasions. The present design minimized the impact of these factors when the analysis was performed on pooled data from both classrooms. This is illustrated in Table 5 for the effect of learning on performance. In future experiments, multiple crossover designs (with repetitions) should be used, together with longer periods between the application of the interventions, to further reduce the possibility of bias. It would also be desirable to extend the period of each intervention beyond the period of one week used in the present experiments.
The observed effects of increased ventilation rate and reduced temperature on the performance of schoolwork by children (Figures 3 and 4) are larger than reported effects on the performance of office work by adults (Wyon and Wargocki 2006a, 2006b). This indicates that children may be more susceptible susceptible /sus·cep·ti·ble/ (su-sep´ti-b'l)
1. readily affected or acted upon.
2. lacking immunity or resistance and thus at risk of infection.
adj. than adults to environmental conditions. The importance of the observed environmental effects on the performance of simple tasks resembling schoolwork for the entire learning process is as yet unknown, although a simple interpretation of the observed effects on speed would be that it would leave more time for learning and leisure, both of which would be expected to improve the long-term Long-term
Three or more years. In the context of accounting, more than 1 year.
1. Of or relating to a gain or loss in the value of a security that has been held over a specific length of time. Compare short-term. learning process. Neither the present results nor the ventilation rate experiments already reported in this series (Wargocki and Wyon 2007) provide any information on the mechanisms by which reduced temperatures or improved ventilation affect performance. It is possible that in the present series of experiments, the effects on performance were caused by the distraction Distraction
Divination (See OMEN.)
a “person from Porlock” interrupted Coleridge while he was recollecting the dream on which he based “Kubla Khan”. [Br. Lit.: Poems of Coleridge in Magill IV, 756] of thermal discomfort (pupils reported that it was significantly warmer when cooling was off, as confirmed by the estimated PMV) and of the perception of poor air quality (pupils and the sensory panel indicated significantly lower classroom air quality when the temperature was high, as would be predicted by the models derived by Fang et al. ). The existence of such mechanisms is implied by the results of the previous studies on the effects of temperature on performance that were recently reviewed by Wyon and Wargocki (2006a). Improved air quality is a possible reason performance improved when the ventilation rate was increased in previously reported experiments in the same series (Wargocki and Wyon 2007) and might be the mechanism for the effects observed in the present study.
Further experiments on possible mechanisms are required, as they are still poorly understood. These should include studies investigating the effects of interaction between temperature and ventilation rate on the performance of schoolwork. This issue could not be examined in the present series, as the interaction was not fully balanced and was confounded with any difference between weeks. Future experiments should also investigate the effects of slowly drifting temperatures on the performance of schoolwork. In the present series, classroom temperatures slowly increased when cooling was off, and this effect could contribute to the observed differences between conditions created in the classrooms, considering that slow temperature changes have been reported to cause discomfort in adults (Wyon and Wargocki 2006a).
The fans in the split units were continuously in operation, both when cooling was on and off, to create a placebo condition. The noise level and air movement generated by the split units should therefore have been similar under both conditions. Nevertheless, pupils indicated that the air was significantly less still and the classroom less noisy Noisy is the name or part of the name of six communes of France:
In the present experiments, the temperature in the classrooms was reduced by split cooling units installed for that purpose. Reduced temperatures can also be achieved by other means, e.g., by using sun-blinds or by operating air-conditioning air-conditioning
Control of temperature, humidity, purity, and motion of air in an enclosed space, independent of outside conditions. In a self-contained air-conditioning unit, air is heated in a boiler unit or cooled by being blown across a refrigerant-filled coil and then units installed in the air-handling unit. The former may restrict the amount of daylight, and this in itself could affect performance, as suggested by studies performed by the Heschong Mahone Ma`hone´
n. 1. A large Turkish ship. Group (2003). Central air conditioning may cause adverse health effects, as suggested by studies with adults in office buildings, reviewed by Seppanen and Fisk Fisk , James 1834-1872.
American railroad financier and speculator who attempted in 1869 to corner the gold market with Jay Gould, leading to Black Friday, a day of nationwide financial panic. (2002). However, as pointed out by Wargocki et al. (2002), most of these studies were not carried out in the summer and consequently could disregard the thermal benefits of air conditioning. For that reason there is a need for further studies on how different methods of avoiding high classroom temperatures affect the performance of school-work by children.
Most temperate countries provide no cooling in schools, so the present findings indicate that the moderately raised classroom temperatures that occur during warm weather make the process of educating children less efficient, as additional effort must be used to overcome the lethargy lethargy /leth·ar·gy/ (leth´ar-je)
1. a lowered level of consciousness, with drowsiness, listlessness, and apathy.
2. a condition of indifference.
1. induced induced /in·duced/ (in-dldbomacst´)
1. produced artificially.
2. produced by induction.
adj artificially caused to occur.
induction. by raised classroom temperatures and the distraction of thermal discomfort rather than to perform more, and more difficult, schoolwork. This is especially the case for those children who find schoolwork to be difficult and are thus unable to exert additional effort. Unsuitably high classroom temperatures may occur for other reasons than an absence of cooling and at other times of year than summertime, and the present results may also apply to these cases, as they serve to confirm the results that were obtained by Wyon (1970) in experiments during the winter in which classroom temperatures were artificially raised. The present results can be generalized gen·er·al·ized
1. Involving an entire organ, as when an epileptic seizure involves all parts of the brain.
2. Not specifically adapted to a particular environment or function; not specialized.
3. to other developed countries where the climate, classroom conditions, level of education, and educational approach are often quite similar to those in Denmark. It seems likely that the observed positive impact on the performance of schoolwork that can be achieved by preventing children from feeling too warm would also occur in warmer climates. However, this assumption will have to be validated val·i·date
tr.v. val·i·dat·ed, val·i·dat·ing, val·i·dates
1. To declare or make legally valid.
2. To mark with an indication of official sanction.
3. by repeating the study in hotter and more humid hu·mid
Containing or characterized by a high amount of water or water vapor: humid air; a humid evening. See Synonyms at wet. climates.
* Reducing moderately high classroom air temperatures in late summer from the region of 25[degrees]C to 20[degrees]C (77[degrees]F to 68[degrees]F), by providing sufficient cooling, improved the performance of two numerical tasks and two language-based tasks resembling schoolwork. Improvement mainly occurred in terms of the speed with which these tasks were performed, with almost no effects on errors. A fairly good agreement in terms of the effects on performance was obtained between two independent experiments carried out one year apart. In both experiments, children's thermal sensation decreased from slightly too warm to neutral, and in one experiment children reported significantly less headache at the lower temperature. A panel of adults visiting the classrooms soon after the children had left found the classroom air quality significantly fresher and more acceptable at the lower temperature. These findings imply that these benefits may have been the mechanisms for the observed effects of temperature on performance.
* Increasing the effective outdoor air supply rate from 5 L/s (11 cfm) per person to 10 L/s (20 cfm) per person improved the performance of four numerical tasks resembling schoolwork by improving the speed at which they were performed, with almost no effects on errors. The effects on performance were similar to the results obtained in other experiments previously reported in this series, providing independent validation.
* The present results require further validation with children in other age groups and in other countries, including those located in warm climates. The importance of the observed effects on simple tasks resembling schoolwork for the entire learning process remains to be demonstrated.
ACKNOWLEDGMENTS See About this product.
The cost of these experiments was borne by ASHRAE Contract RP-1257, Indoor Environmental Effects on the Performance of School Work by Children, and by a grant from the Danish Technical and Scientific Research Council (STVF), which currently supports the International Centre for Indoor Environment and Energy at the Technical University of Denmark The Technical University of Denmark (Danish: Danmarks Tekniske Universitet, DTU) was founded in 1829 as the 'College of Advanced Technology' (Danish: Den Polytekniske Læreanstalt). (DTU DTU Technical University of Denmark
DTU Data Transfer Unit
DTU Data Transmission Unit
DTU Direct To User
DTU Data Terminal Unit
DTU Dry Tree Unit (offshore oil and gas production)
DTU Duval Teachers United ).
Some of the results obtained in this paper have been presented in short conference communications by Wargocki et al. (2005a, 2005b), with the kind permission of ASHRAE. A final report on RP-1257 will eventually be available from ASHRAE and will describe these and other experiments in the same series.
The authors wish to thank the technical section of the local authority responsible for the school in which the experiments were carried out for their cooperation in setting up the experiments; the teachers, parents, and pupils of the school for their participation in them; Sophie Sophie is the French form of Sophia. In English speaking countries, Sophie has often been regarded as a diminutive of "Sophia", but it has also frequently been given as a name in its own right, especially in the United Kingdom where it has been constantly popular since the 1960s. Irgens and Bartlomiej Matysiak, who acted as research assistants in Experiment 1T, and Mateusz Mateusz is a given name, and may refer to:
• , who acted as research assistant in Experiment 2T, reporting them either as their Midterm mid·term
1. The middle of an academic term or a political term of office.
a. An examination given at the middle of a school or college term.
b. midterms A series of such examinations. Project Report or MSc thesis This article or section has multiple issues:
* It may require general cleanup to meet Wikipedia's quality standards.
Please help [ improve the article] or discuss these issues on the talk page.
This article is about the thesis in academia. ; and Cristina Cristina may refer to:
Michael (mī`kəl) [Heb.,=who is like God?], archangel prominent in Christian, Jewish, and Muslim traditions. In the Bible and early Jewish literature, Michael is one of the angels of God's presence. Nielsen Noun 1. Nielsen - Danish composer (1865-1931)
Carl August Nielsen, Carl Nielsen for his help during selection of the school for the study. The authors also thank the anonymous reviewers for their detailed comments that made possible an improvement of the original manuscript manuscript, a handwritten work as distinguished from printing. The oldest manuscripts, those found in Egyptian tombs, were written on papyrus; the earliest dates from c.3500 B.C. .
ASHRAE. 2004. ANSI/ASHRAE Standard 55-2004, Thermal Environmental Conditions for Human Occupancy Gaining or having physical possession of real property subject to, or in the absence of, legal right or title.
In a fire insurance policy, for example, the term occupancy . Atlanta Atlanta (ətlăn`tə, ăt–), city (1990 pop. 394,017), state capital and seat of Fulton co., NW Ga., on the Chattahoochee R. and Peachtree Creek, near the Appalachian foothills; inc. 1847. : American American, river, 30 mi (48 km) long, rising in N central Calif. in the Sierra Nevada and flowing SW into the Sacramento River at Sacramento. The discovery of gold at Sutter's Mill (see Sutter, John Augustus) along the river in 1848 led to the California gold rush of Society of Heating, Refrigerating re·frig·er·ate
tr.v. re·frig·er·at·ed, re·frig·er·at·ing, re·frig·er·ates
1. To cool or chill (a substance).
2. To preserve (food) by chilling. and Air-Conditioning Engineers, Inc.
Baddeley, A.D. 1968. A 3-min. reasoning test based on grammatical reasoning. Psychonomic Science 10:341-42.
CEN. 1998. CEN CR 1752, Ventilation for buildings: Design criteria Noun 1. design criteria - criteria that designers should meet in designing some system or device; "the job specifications summarized the design criteria"
criterion, standard - the ideal in terms of which something can be judged; "they live by the standards of their for the indoor environment. Brussels Brussels (brŭ`səlz), Fr. Bruxelles, Du. Brussel, city and region (1995 pop. 948,122), 63 sq mi (162 sq km), capital of Belgium, central Belgium, on the Senne River and at the junction of the Charleroi-Brussels and Willebroek : European European
emanating from or pertaining to Europe.
European bat lyssavirus
European beech tree
see cryptococcosis. Committee for Standardization standardization
In industry, the development and application of standards that make it possible to manufacture a large volume of interchangeable parts. Standardization may focus on engineering standards, such as properties of materials, fits and tolerances, and drafting .
DHBA. 1995. Building Regulations. Copenhagen Copenhagen (kō`pənhā'gən, –hä'gən), Dan. København (kö'bənhoun`), city (1992 pop. 464,566; metropolitan area 1,339,395), capital of Denmark and of Copenhagen co. , Denmark: Danish Ministry of Housing, Danish Housing and Building Agency.
ECA. 1992. Guidelines guidelines,
n.pl a set of standards, criteria, or specifications to be used or followed in the performance of certain tasks. for ventilation requirements in buildings, Report no. 11, EUR EUR
In currencies, this is the abbreviation for the Euro.
The currency market, also known as the Foreign Exchange market, is the largest financial market in the world, with a daily average volume of over US $1 trillion. 14449 EN, for the European Concerted Action "Indoor Air Quality Indoor Air Quality (IAQ) deals with the content of interior air that could affect health and comfort of building occupants. The IAQ may be compromised by microbial contaminants (mold, bacteria), chemicals (such as carbon monoxide, radon), allergens, or any mass or energy stressor and Its Impact on Man." Luxembourg Luxembourg, province, Belgium
Luxembourg, Du. Luxemburg, province (1991 pop. 232,813), 1,706 sq mi (4,419 sq km), SE Belgium, in the Ardennes, bordering on the Grand Duchy of Luxembourg in the east and on France in the south. : Office for Publications of the European Communities European Community: see European Union.
European Community (EC)
Organization formed in 1967 with the merger of the European Economic Community, European Coal and Steel Community, and European Atomic Energy Community. .
Eriksson, B.E., S. Mandorff, and A. Boysen. 1967. Larare bedomer klassrumsklimatet--en enkat under-sokning (Teachers' opinions of classroom climate--A questionnaire survey), in Swedish. BFR (Big Fast Router) A routing switch (or switch router). See layer 3 switch. Report 31:1967. Stockholm Stockholm (stŏk`hôlm'), city (1995 pop. 692,954), capital of Sweden and of Stockholm co., E Sweden, situated where Lake Mälaren flows into the Baltic Sea. : Building Research Council.
Fang, L., G. Clausen, and P.O. Fanger. 2000. Temperature and humidity humidity, moisture content of the atmosphere, a primary element of climate. Humidity measurements include absolute humidity, the mass of water vapor per unit volume of natural air; relative humidity (usually meant when the term humidity : Important factors for perception of air quality and for ventilation requirements. ASHRAE Transactions 106(2):503-10.
Fanger, P.O. 1970. Thermal Comfort Human thermal comfort is the state of mind that expresses satisfaction with the surrounding environment, according to ASHRAE Standard 55. Achieving thermal comfort for most occupants of buildings or other enclosures is a goal of HVAC design engineers. . Analysis and Applications in Environmental Engineering. Copenhagen: Danish Technical Press.
Heschong Mahone Group. 2003. Windows and Classrooms: A Study of Student Performance and the Indoor Environment, Technical Report. California Energy Commission The California Energy Commission is California’s primary energy policy and planning agency. Created in 1974 and headquartered in Sacramento, the Commission has responsibility for activities that include forecasting future energy needs, promoting energy efficiency through .
Holmberg, I., and D.P. Wyon. 1969. The dependence of performance in school on classroom temperature. Educational and Psychological Interactions 31. Malmo, Sweden: School of Education.
Holmberg, I., and D.P. Wyon. 1972. Systematic observation of classroom behaviour during moderate heat stress. Educational and Psychological Interactions 37. Malmo, Sweden: School of Education.
ISO. 2005. ISO 7730, Ergonomics ergonomics, the engineering science concerned with the physical and psychological relationship between machines and the people who use them. The ergonomicist takes an empirical approach to the study of human-machine interactions. of the thermal environment--Analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria. Brussels: European Committee for Standardization.
McIntyre, D.A. 1980. Indoor Climate. London London, city, Canada
London, city (1991 pop. 303,165), SE Ont., Canada, on the Thames River. The site was chosen in 1792 by Governor Simcoe to be the capital of Upper Canada, but York was made capital instead. London was settled in 1826. : Applied Science.
Mendell, M.J., and G.A. Heath. 2005. Do indoor pollutants pollutants
see environmental pollution. and thermal conditions in schools influence student performance? A critical review of the literature. Indoor Air 15:27-52.
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Ryd, H., and D.P. Wyon. 1970. Methods of evaluating human stress due to climate. Document D6/70, National Swedish Institute The Swedish Institute (Svenska Institutet, SI) is a Swedish government agency with the responsibility to spread information about Sweden abroad, to promote Swedish interests, and to organise exchanges with other countries in different areas of public life, in particular in for Building Research. Stockholm: Building Research Council.
Schoer, L., and J. Shaffran. 1973. A combined evaluation of three separate research projects on the effects of thermal environment on learning and performance. ASHRAE Transactions 79:97-108.
Seppanen, O., and W.J. Fisk. 2002. Association of ventilation system type with SBS symptoms in office workers. Indoor Air 12:98-112.
Taylor, R. 1997. An Introduction to Error Analysis. The Study of Uncertainties in Physical Measurements. Sausalito Sausalito (sô'səlē`tō), residential city (1990 pop. 7,152), Marin co., W Calif., on San Francisco Bay; inc. 1893. It is the northern terminus of the Golden Gate Bridge. The artists' colony there is a tourist attraction. , CA: University Science Books.
Wargocki, P. 2004. Sensory pollution sources in buildings. Indoor Air 14(Suppl 7):82-91.
Wargocki, P., J. Sundell, W. Bischof You may also be looking for people named Bischoff
Bischof (German: bishop) is a surname, and may refer to:
American astronomer noted for his work on stellar photometry. His brother William Henry Pickering , O. Seppanen, and P. Wouters Wouters is a surname, and may refer to;
This page or section lists people with the surname Wouters. . 2002. Ventilation and health in nonindustrial adj. 1. not industrial; - used of societies. Opposite of industrial nt> and industrialized nt>.
Adj. 1. nonindustrial - not having highly developed manufacturing enterprises; "a nonindustrial society" indoor environments. Report from a European Multidisciplinary mul·ti·dis·ci·pli·nar·y
Of, relating to, or making use of several disciplines at once: a multidisciplinary approach to teaching. Scientific Consensus Meeting. Indoor Air 12:113-28.
Wargocki, P., D.P. Wyon, L. Jark, and M. Schaub Schaub may refer to:
Norwegian physician and bacteriologist who discovered (1869) the leprosy bacillus. . 2005a. The effects of outdoor air supply rates in classrooms on the performance of schoolwork by children. Proceedings of CLIMA CLIMA Computational Logic In Multi-Agent systems
CLIMA Center for Legumes in Mediterranean Agriculture (Australia) 2005, on CD-ROM CD-ROM: see compact disc.
in full compact disc read-only memory
Type of computer storage medium that is read optically (e.g., by a laser). .
Wargocki, P., D.P. Wyon, B. Matysiak, and S. Irgens. 2005b. The effects of classroom air temperature and outdoor air supply rate on performance of school work by children. Proceedings of Indoor Air 2005 I(1):368-72.
Wargocki, P., and D.P. Wyon. 2007. The effects of outdoor air supply rate and supply air filter condition in classrooms on the performance of schoolwork by children (1257-RP). HVAC (Heating Ventilation Air Conditioning) In the home or small office with a handful of computers, HVAC is more for human comfort than the machines. In large datacenters, a humidity-free room with a steady, cool temperature is essential for the trouble-free & R Research 13(2):165-91.
Wyon, D.P. 1969. The effects of moderate heat stress on the mental performance of children. Document D8/69, National Swedish Institute for Building Research. Stockholm: Building Research Council.
Wyon, D.P. 1970. Studies of children under imposed noise and heat stress. Ergonomics 13(5):598-612.
Wyon, D.P., and I. Holmberg. 1972. Systematic observation of classroom behaviour during moderate heat stress. Proceedings of the CIB CIB
Latin cibus (food) (W45) Symposium symposium
In ancient Greece, an aristocratic banquet at which men met to discuss philosophical and political issues and recite poetry. It began as a warrior feast. Rooms were designed specifically for the proceedings. "Thermal Comfort and Moderate Heat Stress," September 13-15, Garston Garston could refer to several places: United Kingdom
Wyon, D.P., and P. Wargocki. 2006a. Room temperature effects on office work. In D. Croome (ed.), Creating the Productive Environment, 2d ed., pp. 181-92. London: Taylor & Francis Francis, French prince, duke of Alençon and Anjou
Francis, 1554–84, French prince, duke of Alençon and Anjou; youngest son of King Henry II of France and Catherine de' Medici. .
Wyon, D.P., and P. Wargocki. 2006b. Indoor air quality effects on office work", In D. Croome (ed.), Creating the Productive Environment, 2d ed., pp. 193-205. London: Taylor & Francis.
Yaglou, C.P., E.C. Riley, and D.I. Coggins. 1936. Ventilation requirements. ASHVE ASHVE American Society of Heating and Ventilating Engineers (now part of American Society of Heating, Refrigerating and Air-Conditioning Engineers) Transactions 42:133-62.
Pawel Wargocki, PhD
David P. Wyon, PhD
Received February February: see month. 14, 2006; accepted June June: see month. 7, 2006
Pawel Wargocki and David P. Wyon are with the International Centre for Indoor Environment and Energy, Department of Mechanical Engineering, Technical University of Denmark, Lyngby, Denmark. Wargocki is also vice-president vice president or vice-pres·i·dent
n. Abbr. VP
1. An officer ranking next below a president, usually empowered to assume the president's duties under conditions such as absence, illness, or death.
2. for research of the International Society for Indoor Air Quality.
Table 1. The Partially Balanced Design of Experiments 1T and 2T Experiment 1T, Summer Week Classroom 1 Classroom 2 1 Ventilation rate high Ventilation rate low Air temperature low Air temperature high 2 Ventilation rate high Ventilation rate low Air temperature high Air temperature low Week break due to excursion 3 Ventilation rate low Ventilation rate high Air temperature high Air temperature low 4 Ventilation rate low Ventilation rate high Air temperature low Air temperature high Experiment 2T, Summer Week Classroom 1 Classroom 2 1 Ventilation rate low Air temperature high Air temperature low 2 Ventilation rate low Air temperature low Air temperature high 3 4 Table 2. Average Values of Continuous Measurements Made When Classrooms Were Occupied by Children and Estimated Ventilation Rates Experiment 1T, Summer Ventilation Rate Low Air Temperature Parameter High Low Classroom temperature, 24.6[+ or -]1.3 19.2[+ or -]0.8 mean[+ or -]sd, [degrees]C (a) Classroom temperature 20.6-26.7 17.7-21.5 range, min-max, [degrees]C Classroom RH, 52[+ or -]8 54[+ or -]4 mean[+ or -]sd, % (a) Classroom C[O.sub.2], 952[+ or -]232 1049[+ or -]154 mean[+ or -]sd, ppm (a) Average classroom 1138 1218 peak C[O.sub.2], ppm Total time with 1 or more 13.4 5.4 windows opened, h Estimated effective 468[+ or -]157 402[+ or -]103 ventilation rate, [m.sup.3]/ h (b) Average number of 22+1 22+1 pupils + teacher, per class Estimated effective 5.7[+ or -]2.1 4.7[+ or -]1.3 ventilation rate, L/s per person (b) Experiment 1T, Summer Ventilation Rate High Air Temperature Parameter High Low Classroom temperature, 22.5[+ or -]0.9 20.8[+ or -]0.9 mean[+ or -]sd, [degrees]C (a) Classroom temperature 20.6-25.7 18.5-23.0 range, min-max, [degrees]C Classroom RH, 49[+ or -]8 56[+ or -]8 mean[+ or -]sd, % (a) Classroom C[O.sub.2], 744[+ or -]176 809[+ or -]148 mean[+ or -]sd, ppm (a) Average classroom 831 843 peak C[O.sub.2], ppm Total time with 1 or more 11.8 6.7 windows opened, h Estimated effective 881[+ or -]176 800[+ or -]198 ventilation rate, [m.sup.3]/ h (b) Average number of 24+1 23+1 pupils + teacher, per class Estimated effective 9.9[+ or -]1.6 9.3[+ or -]2.2 ventilation rate, L/s per person (b) Experiment 2T, Summer Ventilation Rate Low Air Temperature Parameter High Low Classroom temperature, 24.9[+ or -]1.7 21.6[+ or -]1.6 mean[+ or -]sd, [degrees]C (a) Classroom temperature 20.8-28.1 19.0-25.8 range, min-max, [degrees]C Classroom RH, 52[+ or -]4 52[+ or -]6 mean[+ or -]sd, % (a) Classroom C[O.sub.2], 1230[+ or -]325 1462[+ or -]412 mean[+ or -]sd, ppm (a) Average classroom 1424 1721 peak C[O.sub.2], ppm Total time with 1 or more 13.7 4.8 windows opened, h Estimated effective 332[+ or -]122 247[+ or -]41 ventilation rate, [m.sup.3]/ h (b) Average number of 24+1 24+1 pupils + teacher, per class Estimated effective 3.7[+ or -]1.1 2.7[+ or -]0.4 ventilation rate, L/s per person (b) a. Experiment 1T: outdoor temperature = 17.4[degrees]C[+ or -] 1.8[degrees]C, RH = 69%[+ or -]12%; C[O.sub.2] = 400[+ or -]17 ppm; Experiment 2T: outdoor temperature = 15.7[degrees]C[+ or -] 1.8[degrees]C, RH = 68%[+ or -]8%; C[O.sub.2] = 378[+ or -]11 ppm. b. Experiment 1T: average production rate of C[O.sub.2] = 17.7[+ or -] 1.3 L/h per person (10-year-old children + teacher); Experiment 2T: average production rate of C[O.sub.2] = 17.5[+ or -] 1.5 L/h per person (11-year-old children + teacher). Table 3. Average Conditions (Mean[+ or -]SD) in Empty Classrooms, as Determined by Spot Measurements at the End of Each Intervention Experiment 1T, Summer Ventilation Rate Low Air Temperature Parameter High Low Air velocity [m/s] 0.04[+ or -]0.03 0.11[+ or -]0.07 Noise level [dB(A)] 36 35 Particles > 0.02 [micro]m (ultrafines) 3435 8383 [counts/[cm.sup.3]] > 0.75 [micro]m [counts/ 308 1673 1000 [cm.sup.3]] > 1.0 [micro]m [counts/ N/A 1000 [cm.sup.3]] > 2.0 [micro]m [counts/ 1000 [cm.sup.3]] > 3.5 [micro]m [counts/ 1000 [cm.sup.3]] > 5.0 [micro]m [counts/ 1000 [cm.sup.3]] > 7.5 [micro]m [counts/ 1000 [cm.sup.3]] > 10.0 [micro]m [counts/ 1000 [cm.sup.3]] > 15.0 [micro]m [counts/ 2 2 1000 [cm.sup.3]] Settled dust N/A [% covering of a glass plate] Experiment 1T, Summer Ventilation Rate High Air Temperature Parameter High Low Air velocity [m/s] 0.09[+ or -]0.05 0.11[+ or -]0.06 Noise level [dB(A)] 39 38 Particles > 0.02 [micro]m (ultrafines) 2700 2030 [counts/[cm.sup.3]] > 0.75 [micro]m [counts/ 717 256 1000 [cm.sup.3]] > 1.0 [micro]m [counts/ N/A 1000 [cm.sup.3]] > 2.0 [micro]m [counts/ 1000 [cm.sup.3]] > 3.5 [micro]m [counts/ 1000 [cm.sup.3]] > 5.0 [micro]m [counts/ 1000 [cm.sup.3]] > 7.5 [micro]m [counts/ 1000 [cm.sup.3]] > 10.0 [micro]m [counts/ 1000 [cm.sup.3]] > 15.0 [micro]m [counts/ 2 1 1000 [cm.sup.3]] Settled dust N/A [% covering of a glass plate] Experiment 2T, Summer Ventilation Rate Low Air Temperature Parameter High Low Air velocity [m/s] 0.05[+ or -]0.02 0.15[+ or -]0.09 Noise level [dB(A)] 44[+ or -]3 44[+ or -]4 Particles > 0.02 [micro]m (ultrafines) N/A [counts/[cm.sup.3]] > 0.75 [micro]m [counts/ 2479 1192 1000 [cm.sup.3]] > 1.0 [micro]m [counts/ 1480 639 1000 [cm.sup.3]] > 2.0 [micro]m [counts/ 644 262 1000 [cm.sup.3]] > 3.5 [micro]m [counts/ 247 106 1000 [cm.sup.3]] > 5.0 [micro]m [counts/ 83 46 1000 [cm.sup.3]] > 7.5 [micro]m [counts/ 27 21 1000 [cm.sup.3]] > 10.0 [micro]m [counts/ 12 10 1000 [cm.sup.3]] > 15.0 [micro]m [counts/ 3 3 1000 [cm.sup.3]] Settled dust 1.89[+ or -]0.24 2.73[+ or -]0.62 [% covering of a glass plate] Table 4. Performance of Schoolwork by Children (Mean[+ or -]se); Significant Differences Shown in Bold Experiment 1T, Summer Ventilation Rate Number of Low Performance Performance Pupils Total Air Temperature Exercise Metric (Class 1/2) High Subtraction Attempted 44 (20/24) 2.53[+ or -]0.40 (a) units per min (1.94[+ or -]0.31) (b) Percentage 17.38[+ or -]5.37 (a) errors Multiplication Attempted 45 (21/24) 1.66[+ or -]0.31 (a) units per min (1.49[+ or -]0.11) (b) Percentage 33.42[+ or -]5.81 (a) errors Number Attempted 44 (19/25) 14.34[+ or -]0.89 (a) Comparison units per min (11.81[+ or -]0.97) (b) Percentage 1.77[+ or -]0.43 (a) errors Addition Attempted 42 (18/24) 4.52[+ or -]0.48 (a) units per min (3.70[+ or -]0.16) (b) Percentage 6.38[+ or -]1.41 (a) errors Logical Attempted 32 (16/16) 7.43[+ or -]0.36 Reasoning units per min Percentage 24.62[+ or -]3.92 errors Acoustic Percentage 34 (16/18) 46.82[+ or -]3.88 Proofreading errors Percentage 3.02[+ or -]0.60 false positives Reading and Attempted 40 (18/22) 1.31[+ or -]0.07 Comprehension units per min Percentage 31.71[+ or -]2.73 errors Proofreading Attempted 40 (18/22) N/A (due to missing data) units per min Percentage 48.28[+ or -]3.29 errors Percentage 9.15[+ or -]1.58 false positives Experiment 1T, Summer Ventilation Rate Low High Performance Performance Air Temperature Exercise Metric Low High Subtraction Attempted 2.71[+ or -]0.26 2.44[+ or -] units per min 0.18 (2.69[+ or -]0.16) (b) (2.43[+ or -] 0.17) (b) Percentage 17.46[+ or -]3.47 11.84[+ or -] errors 2.53 Multiplication Attempted 1.43[+ or -]0.14 1.78[+ or -] units per min 0.18 (1.46[+ or -]0.96) (b) (1.81[+ or -] 0.06) (b) Percentage 31.39[+ or -]4.22 23.59[+ or -] errors 3.62 Number Attempted 14.73[+ or -]0.66 15.30[+ or -] Comparison units per min 0.90 (14.61[+ or -]0.50) (b) (15.24[+ or -] 0.52) (b) Percentage 3.87[+ or -]0.83 4.78[+ or -] errors 0.99 Addition Attempted 4.05[+ or -]0.33 4.39[+ or -] units per min 0.34 (4.06[+ or -]0.11) (b) (4.40[+ or -] 0.10) (b) Percentage 10.68[+ or -]3.01 6.88[+ or -] errors 1.35 Logical Attempted 7.07[+ or -]0.49 6.86[+ or -] Reasoning units per min 0.45 Percentage 21.87[+ or -]3.97 21.80[+ or -] errors 3.44 Acoustic Percentage 39.33[+ or -]3.94 42.18[+ or -] Proofreading errors 3.18 Percentage 2.09[+ or -]0.59 1.55[+ or -] false 0.53 positives Reading and Attempted 1.65[+ or -]0.11 1.32[+ or -] Comprehension units per min 0.09 Percentage 25.49[+ or -]2.70 27.29[+ or -] errors 3.31 Proofreading Attempted N/A (due to missing data) units per min Percentage 54.00[+ or -]3.19 (a) 52.64[+ or -] errors 4.63 (a) Percentage 8.64[+ or -]1.96 (a) 7.55[+ or -] false 2.65 (a) positives Experiment 1T, Summer Ventilation Rate Difference Between High Conditions Performance Performance Air Temperature Exercise Metric Low Test Subtraction Attempted 3.06[+ or -]0.25 2 x 2 units per min (3.06[+ or -] ANOVA 0.16) (b) Percentage 13.65[+ or -]2.76 Wilcoxon errors Multiplication Attempted 1.77[+ or -]0.15 2 x 2 units per min (1.78[+ or -] ANOVA 0.06) (b) Percentage 26.11[+ or -]3.95 Wilcoxon (a) errors Number Attempted 14.08[+ or -]0.78 2 x 2 Comparison units per min 13.94[+ or -] ANOVA (c) 0.51) (b) Percentage 3.66[+ or -]0.72 Wilcoxon errors Addition Attempted 4.51[+ or -]0.32 2 x 2 units per min (4.55[+ or -] ANOVA 0.10) (b) Percentage 6.50[+ or -]1.37 Wilcoxon (a) errors Logical Attempted 7.44[+ or -]0.45 Wilcoxon Reasoning units per min Percentage 20.93[+ or -]3.61 Wilcoxon (e) errors Acoustic Percentage 40.90[+ or -]3.05 2 x 2 Proofreading errors ANOVA (f) Percentage 2.14[+ or -]0.57 Wilcoxon (e) false positives Reading and Attempted 1.62[+ or -]0.10 2 x 2 Comprehension units per min ANOVA (f) Percentage 27.71[+ or -]2.87 Wilcoxon (e) errors Proofreading Attempted N/A (due to missing data) units per min Percentage 45.58[+ or -]2.68 Wilcoxon errors Percentage 7.03[+ or -]1.64 Wilcoxon false positives Experiment 1T, Summer Experiment Difference Between 2T, Summer Conditions Number of Performance Performance Temperature Ventilation Pupils Total Exercise Metric P < P < (Class 1/2) Subtraction Attempted N/A (c) N/A (c) 42 (18/24) units per min (0.006)# (b) (0.014)# (b) Percentage N/A (c) N/A (c) errors (0.14) (d) (0.06) (d) Multiplication Attempted N/A (c) N/A (c) N/A units per min (0.41) (b) (0.013)# (b) Percentage N/A (c) N/A (c) errors (0.56) (d) (0.05)# (d) Number Attempted N/A (c) N/A (c) N/A Comparison units per min (0.10) (b) (0.043)# (b) Percentage N/A (c) N/A (c) errors (0.24) (d) (0.75) (d) Addition Attempted N/A (c) N/A (c) 42 (18/24) units per min (0.041#) (b) (0.001#) (b) Percentage N/A (c) N/A (c) errors (0.90) (d) (0.23) (d) Logical Attempted 0.62 0.49 41 (18/23) Reasoning units per min Percentage 0.27 0.47 errors Acoustic Percentage 0.043# 0.96 43 (19/24) Proofreading errors Percentage 0.84 0.19 false positives Reading and Attempted 0.001# 0.78 43 (19/24) Comprehension units per min Percentage 0.41 0.58 errors Proofreading Attempted N/A (due to missing data) N/A units per min Percentage N/A (g) N/A (g) errors Percentage N/A (g) N/A (g) false positives Experiment 2T, Summer Ventilation Rate Low Wilcoxon Performance Performance Air Temperature Test Exercise Metric High Low P < Subtraction Attempted 4.26[+ or -] 5.00[+ or -] 0.06 units per min 0.40 0.32 Percentage 10.43[+ or -] 6.47[+ or -] 0.08 errors 1.96 0.95 Multiplication Attempted N/A units per min Percentage errors Number Attempted N/A Comparison units per min Percentage errors Addition Attempted 4.37[+ or -] 4.68[+ or -] 0.002# units per min 0.28 0.27 Percentage 5.89[+ or -] 4.29[+ or -] 0.86 errors 2.23 0.75 Logical Attempted 7.89[+ or -] 8.25[+ or -] 0.60 Reasoning units per min 0.40 0.47 Percentage 26.00[+ or -] 26.37[+ or -] 0.56 errors 3.43 3.17 Acoustic Percentage 29.93[+ or -] 29.22[+ or -] 0.76 Proofreading errors 2.78 2.93 Percentage 2.26[+ or -] 4.52[+ or -] 0.007# false 0.51 0.87 positives Reading and Attempted 1.53[+ or -] 1.66[+ or -] 0.59 Comprehension units per min 0.07 0.13 Percentage 26.13[+ or -] 24.00[+ or -] 0.71 errors 3.71 3.30 Proofreading Attempted N/A units per min Percentage errors Percentage false positives a. Test results from one class only. b. The results from GLM analysis, including missing data showing adjusted means and P-values. c. Due to missing data in one condition for one class, the test on a complete balanced design was not possible. d. Wilcoxon test for all data, including pupils who missed some conditions. e. Difference between conditions tested using Friedman ANOVA: percentage errors in logical reasoning (P = 0.64); percentage false positives in acoustic proofreading (P = 0.24); percentage errors in reading and comprehension (P = 0.56). f. After transforming data using the base-10 logarithm. g. Analyses not available due to missing data under two conditions in two classes. Note: Significant Differences Shown in indicated with #. Table 5. Summary of Intervention Effects on Performance (a) Adjusting for Experiment 1T, Summer Significant Data from Pupils Who Had Increase of Speed Performed the Exercise in in the Course of All Four Conditions the Experiment (Complete Design) Performance Independently of Number Exercise the Interventions of pupils Temperature Ventilation Subtraction Not adjusted 44 N/A N/A (Speed) Adjusted N/A N/A Multiplication Not adjusted 45 N/A N/A (Speed) Adjusted N/A N/A Multiplication Not adjusted 45 N/A N/A (Percentage Adjusted N/A N/A errors) Number Not adjusted 44 N/A N/A Comparison (Speed) Adjusted N/A N/A Addition Not adjusted 42 N/A N/A (Speed) Adjusted N/A N/A Reading and Not adjusted 40 [up arrow] NS Comprehension (Speed) Adjusted [up arrow] NS Acoustic Not adjusted 34 [up arrow] NS Proofreading (Percentage Adjusted [up arrow] NS errors) Acoustic Not adjusted 34 NS NS Proofreading (Percentage Adjusted NS NS false positives) Experiment 1T, Summer Adjusting for All Available Data, i.e., Significant Including Pupils Who Increase of Speed Had Not Taken the Task in the Course of in All Four Conditions the Experiment (Incomplete Design) Performance Independently of Number Exercise the Interventions of Pupils Temperature Ventilation Subtraction Not adjusted 48 [up arrow] [up arrow] (Speed) Adjusted N/A N/A Multiplication Not adjusted 48 N/S [up arrow] (Speed) Adjusted N/A N/A Multiplication Not adjusted 49 NS [up arrow] (Percentage Adjusted N/A N/A errors) Number Not adjusted 48 NS [up arrow] Comparison (Speed) Adjusted N/A N/A Addition Not adjusted 48 [up arrow] [up arrow] (Speed) Adjusted N/A N/A Reading and Not adjusted 48 [up arrow] NS Comprehension (Speed) Adjusted [up arrow] NS Acoustic Not adjusted 47 NS NS Proofreading (Percentage Adjusted [up arrow] NS errors) Acoustic Not adjusted 49 NS NS Proofreading (Percentage Adjusted NS NS false positives) Adjusting for Experiment 2T, Summer Significant Data from Pupils Who Increase of Speed Had Performed in the Course of the Exercise in the Experiment Both Conditions Performance Independently of (Complete Design) Exercise the Interventions Number of Pupils Temperature Subtraction Not adjusted 42 NS (Speed) Adjusted [up arrow] Multiplication Not adjusted N/A (Speed) Adjusted Multiplication Not adjusted N/A (Percentage Adjusted errors) Number Not adjusted N/A Comparison (Speed) Adjusted Addition Not adjusted 42 [up arrow] (Speed) Adjusted N/A Reading and Not adjusted 43 NS Comprehension (Speed) Adjusted NS Acoustic Not adjusted 43 NS Proofreading (Percentage Adjusted N/A errors) Acoustic Not adjusted 43 [down arrow] Proofreading (Percentage Adjusted N/A false positives) Adjusting for Experiment 2T, Summer Significant All Available Data, i.e., Increase of Speed Including Pupils Who Had in the Course of Not Performed the Exercise the Experiment in Both Conditions Performance Independently of (Incomplete Design) Exercise the Interventions Number of Pupils Temperature Subtraction Not adjusted 47 NS (Speed) Adjusted [up arrow] Multiplication Not adjusted N/A (Speed) Adjusted Multiplication Not adjusted N/A (Percentage Adjusted errors) Number Not adjusted N/A Comparison (Speed) Adjusted Addition Not adjusted 49 [up arrow] (Speed) Adjusted N/A Reading and Not adjusted 49 NS Comprehension (Speed) Adjusted NS Acoustic Not adjusted N/A N/A Proofreading (Percentage Adjusted N/A errors) Acoustic Not adjusted N/A N/A Proofreading (Percentage Adjusted N/A false positives) a. The table shows the effects on speed, errors, or false positives for exercises in which significant differences between conditions were observed. An arrow pointing up ([up arrow]) indicates that performance significantly improved (i.e., speed increased or percentage errors or false positives decreased) when the outdoor air supply rate increased or a temperature was reduced. An arrow pointing down ([down arrow]) indicates that performance significantly reduced (i.e., speed decreased or percentage errors or false positives increased). NS = not significant. Table 6. Results Obtained on the Visual Analogue Scales Marked Each Week by the Children (Mean[+ or -]se, Median); Significant Differences Shown in Bold Experiment 1T, Summer Ventilation Rate Low Perceptions/Symptoms Number Air Temperature (Coding) of Pupils High Low Too cold (0)-- 39 66.9[+ or -]3.1 46.1[+ or -]3.8 Too warm (100) 60.9 40.1 There is a draft (0)-- 39 73.7[+ or -]3.8 56.7[+ or -]4.2 The air is still (100) 85.0 48.0 The air is humid (0)-- 35 61.2[+ or -]4.1 54.3[+ or -]3.6 The air is dry (100) 52.0 52.3 The air is poor (0)-- 35 61.1[+ or -]5.7 64.6[+ or -]5.2 The air is fresh (100) 67.9 74.9 Too little light (0)-- 37 50.1[+ or -]2.1 40.8[+ or -]2.9 Too much light (100) 48.9 47.7 Too noisy (0)-- 38 69.7[+ or -]4.2 61.2[+ or -]4.1 Quiet (100) 75.5 55.5 Nose blocked (0)-- 39 69.5[+ or -]4.9 62.4[+ or -]5.2 Nose fine (100) 78.3 59.9 Throat dry (0)-- 38 56.8[+ or -]5.9 58.6[+ or -]6.2 Throat fine (100) 54.6 69.1 Lips dry (0)-- 38 48.1[+ or -]5.9 41.0[+ or -]5.8 Lips not dry (100) 42.4 29.5 Skin dry (0)-- 37 65.4[+ or -]4.7 62.7[+ or -]5.8 Skin not dry (100) 62.7 71.9 Eyes hurt (0)-- N/A Eyes not hurt (100) Very hungry (0)-- 39 41.5[+ or -]4.7 40.2[+ or -]4.7 Full (100) 40.4 35.2 Slept badly last night 39 74.7[+ or -]3.9 75.7[+ or -]4.3 (0)-- Slept well last night 83.5 85.0 (100) Feeling very tired 39 54.3[+ or -]4.9 51.4[+ or -]5.4 (0)-- Not feeling tired at 47.4 49.2 all (100) Slept too little last 39 59.5[+ or -]4.2 64.3[+ or -]4.9 night (0)-- Slept too long last 54.1 68.2 night (100) Sleepy (0)-- N/A Awake (100) Does not feel like 39 49.7[+ or -]5.0 46.2[+ or -]5.6 working today (0)-- Feels like working 48.3 45.6 today (100) Having a headache N/A (0)-- Not having a headache at all (100) Difference Experiment 1T, Summer between Ventilation Rate Conditions High (Friedman Perceptions/Symptoms Ait Temperature ANOVA) (Coding) High Low P-value Too cold (0)-- 54.9[+ or -]3.0 50.3[+ or -]3.2 <0.001# Too warm (100) 48.3 48.0 There is a draft (0)-- 70.1[+ or -]4.0 58.6[+ or -]3.5 <0.001# The air is still (100) 74.9 50.2 The air is humid (0)-- 59.2[+ or -]3.9 54.9[+ or -]3.5 0.99 The air is dry (100) 48.9 49.9 The air is poor (0)-- 58.0[+ or -]5.9 72.3[+ or -]4.4 0.022# The air is fresh (100) 50.5 76.5 Too little light (0)-- 49.2[+ or -]2.8 45.4[+ or -]2.1 0.16 Too much light (100) 48.3 48.0 Too noisy (0)-- 51.6[+ or -]4.2 55.3[+ or -]4.0 0.021# Quiet (100) 49.1 50.3 Nose blocked (0)-- 63.6[+ or -]5.3 73.8[+ or -]4.9 0.29 Nose fine (100) 70.6 89.9 Throat dry (0)-- 53.5[+ or -]5.9 56.3[+ or -]6.0 0.98 Throat fine (100) 48.9 60.7 Lips dry (0)-- 40.9[+ or -]6.1 43.4[+ or -]5.6 0.55 Lips not dry (100) 34.4 41.4 Skin dry (0)-- 59.1[+ or -]5.7 63.8[+ or -]5.1 0.67 Skin not dry (100) 59.3 66.4 Eyes hurt (0)-- N/A Eyes not hurt (100) Very hungry (0)-- 43.3[+ or -]5.1 32.2[+ or -]4.0 0.21 Full (100) 38.5 35.8 Slept badly last night 74.4[+ or -]4.4 71.9[+ or -]4.3 0.83 (0)-- Slept well last night 86.9 80.1 (100) Feeling very tired 50.2[+ or -]5.5 56.2[+ or -]5.2 0.50 (0)-- Not feeling tired at 46.2 49.2 all (100) Slept too little last 59.6[+ or -]4.6 52.6[+ or -]5.0 0.38 night (0)-- Slept too long last 53.8 49.9 night (100) Sleepy (0)-- N/A Awake (100) Does not feel like 46.2[+ or -]5.8 52.0[+ or -]5.6 0.31 working today (0)-- Feels like working 36.1 50.0 today (100) Having a headache N/A (0)-- Not having a headache at all (100) Experiment 1T, Summer Main Effects (Wilcoxon Test) Perceptions/Symptoms P-value Experiment 2T, Summer (Coding) Temperature Ventilation Number of Pupils Too cold (0)-- <0.001 (a)# 0.21 41 Too warm (100) There is a draft (0)-- <0.001 (a)# 0.89 40 The air is still (100) The air is humid (0)-- 0.26 (a) 0.64 40 The air is dry (100) The air is poor (0)-- 0.028 (a)# 0.60 41 The air is fresh (100) Too little light (0)-- 0.009 (a)# 0.66 41 Too much light (100) Too noisy (0)-- 0.55 0.009 (a)# 40 Quiet (100) Nose blocked (0)-- 0.53 0.29 41 Nose fine (100) Throat dry (0)-- 0.64 0.62 41 Throat fine (100) Lips dry (0)-- 0.61 0.52 40 Lips not dry (100) Skin dry (0)-- 0.40 0.96 41 Skin not dry (100) Eyes hurt (0)-- N/A 41 Eyes not hurt (100) Very hungry (0)-- 0.063 (a) 0.34 41 Full (100) Slept badly last night 0.50 0.50 40 (0)-- Slept well last night (100) Feeling very tired 0.21 0.93 41 (0)-- Not feeling tired at all (100) Slept too little last 0.83 0.23 40 night (0)-- Slept too long last night (100) Sleepy (0)-- N/A 40 Awake (100) Does not feel like 0.97 0.99 41 working today (0)-- Feels like working today (100) Having a headache N/A 41 (0)-- Not having a headache at all (100) Experiment 2T, Summer Ventilation Rate Low Wilcoxon Perceptions/Symptoms Air Temperature Test (Coding) High Low P-value Too cold (0)-- 62.6[+ or -]2.9 50.3[+ or -]2.4 0.002# Too warm (100) 63.2 49.1 There is a draft (0)-- 65.6[+ or -]3.6 60.5[+ or -]3.4 0.23 The air is still (100) 65.9 57.0 The air is humid (0)-- 59.2[+ or -]3.6 56.0[+ or -]2.7 0.44 The air is dry (100) 55.0 49.0 The air is poor (0)-- 55.3[+ or -]4.2 56.3[+ or -]3.5 0.91 The air is fresh (100) 49.6 60.2 Too little light (0)-- 51.8[+ or -]2.0 44.6[+ or -]2.5 0.017# Too much light (100) 50.4 47.7 Too noisy (0)-- 52.0[+ or -]4.3 63.1[+ or -]4.9 0.008# Quiet (100) 47.2 67.8 Nose blocked (0)-- 59.5[+ or -]5.2 67.7[+ or -]4.6 0.39 Nose fine (100) 64.7 79.7 Throat dry (0)-- 52.3[+ or -]4.8 53.9[+ or -]5.0 0.74 Throat fine (100) 50.7 51.6 Lips dry (0)-- 51.0[+ or -]4.7 51.0[+ or -]4.4 1.0 Lips not dry (100) 48.8 49.1 Skin dry (0)-- 60.2[+ or -]4.1 60.0[+ or -]4.5 0.96 Skin not dry (100) 53.7 50.7 Eyes hurt (0)-- 66.4[+ or -]4.7 70.2[+ or -]4.7 0.86 Eyes not hurt (100) 65.9 82.2 Very hungry (0)-- 23.2[+ or -]3.6 30.0[+ or -]3.2 0.07 Full (100) 19.6 29.4 Slept badly last night 78.5[+ or -]4.0 73.3[+ or -]4.4 0.36 (0)-- Slept well last night 91.4 79.6 (100) Feeling very tired 59.0[+ or -]4.6 52.7[+ or -]4.5 0.26 (0)-- Not feeling tired at 55.5 45.4 all (100) Slept too little last 58.6[+ or -]5.0 54.1[+ or -]4.4 0.38 night (0)-- Slept too long last 55.8 50.7 night (100) Sleepy (0)-- 62.6[+ or -]4.7 64.3[+ or -]4.2 0.64 Awake (100) 59.6 67.2 Does not feel like 39.6[+ or -]4.8 44.4[+ or -]4.3 0.40 working today (0)-- Feels like working 40.7 47.7 today (100) Having a headache 61.0[+ or -]4.8 75.2[+ or -]4.6 0.025# (0)-- Not having a headache 52.8 88.2 at all (100) a. In the analysis of all ratings including pupils who did not mark the scales in all conditions (N = 48), the effects were as follows: Too cold--Too warm (P < 0.001); There is a draft--The air is still (P < 0.001); The air is humid--The air is dry (P = 0.027); The air is poor-- The air is fresh (P = 0.053); Too little light--Too much light (P = 0.023); Too noisy--Quiet (P < 0.001); Very hungry--Full (P = 0.059). Note: Significant Differences Shown in indicated with #. Table 7. Thermal State of the Children Experiment 1T, Summer Ventilation Rate Low High Air Temperature High Low High Visual Analogue Scale: Too cold (0)--Too warm (100) Mean[+ or -]SE 66.9[+ or -]3.1 46.1[+ or -]3.8 54.9[+ or -]3.0 Median 60.9 40.1 48.3 (25th percentile, (49.8; 84.7) (30.0; 53.5) (45.3; 63.6) 75th percentile) Estimated Thermal Sensation (a) PMV 0.81 -0.25 0.38 PPD 19% 6% 8% Experiment 1T, Summer Experiment 2T, Summer Ventilation Rate Ventilation Rate High Low Air Temperature Air Temperature Low High Low Visual Analogue Scale: Too cold (0)--Too warm (100) Mean[+ or -]SE 50.3[+ or -]3.2 62.6[+ or -]2.9 50.3[+ or -]2.4 Median 48.0 63.2 49.1 (25th percentile, (39.1; 59.3) (47.5; 78.0) (45.9; 56.1) 75th percentile) Estimated Thermal Sensation (a) PMV 0.06 0.87 0.11 PPD 5% 21% 5% a. Assumed: clo = 0.6, met = 1.7; operative temperature = air temperature. Table 8. Adult Sensory Panel Assessments of Classroom Air Quality (Mean[+ or -]se, Median); Significant Differences Shown in Bold Experiment 2T, Summer Ventilation Rate Low Perceptions/Symptoms Experiment Number of Air Temperature (Coding) 1T, Summer Subjects High Acceptability of air quality N/A 28 0.143[+ or -] (Clearly not acceptable = 0.049 -1 - Clearly acceptable = 1) 0.158 Odor intensity (No odor = 0 - 28 16.7[+ or -]1.1 Overpowering odor = 50) 14.8 Air freshness (Air stuffy = 28 43.6[+ or -]2.7 0 - Air fresh = 100) 40.5 Perceived dryness of air 28 53.8[+ or -]2.5 (Air humid = 0 - Air dry = 51.5 100) Experiment 2T, Summer Ventilation Rate Low Perceptions/Symptoms Air Temperature Wilcoxon Test (Coding) Low P-value Acceptability of air quality 0.385[+ or -]0.061 < 0.001# (Clearly not acceptable = 0.523 -1 - Clearly acceptable = 1) Odor intensity (No odor = 0 - 18.6[+ or -]2.2 0.92 Overpowering odor = 50) 14.3 Air freshness (Air stuffy = 68.2[+ or -]3.6 < 0.001# 0 - Air fresh = 100) 77.3 Perceived dryness of air 48.9[+ or -]2.3 0.25 (Air humid = 0 - Air dry = 49.3 100) Note: Significant Differences Shown in indicated with #.