Portable heaters are excellent in emergencies when a furnace breaks down or there is an interruption in gas or electrical service.
For best results, place heater under a window to warm cold air as it enters the room, whether through an ill-fitting window frame or just off the cold glass.
Electric space heaters should be plugged directly into the wall outlet; if an extension cord is necessary, it must be heavy duty (14-gauge wire).
Heating elements are either "black heat," with the heating wire wound around porcelain insulators or the more popular "instant heat" that utilizes a ribbon element.
Heating capacity is rated in BTUs. Wattage ratings of heaters can be converted to BTUs consumed per hour by multiplying the number of watts by 3.413 (the number of BTUs equaling one watt).
Better electric heaters generally feature a tip-over safety switch, which automatically shuts the heater off if knocked over.
Some models have a thermostat, and some have small fans to force heated air into the open room.
Unlike traditional convection heating systems that warm the air in a room, radiant heaters bombard objects directly with infrared heat. Quartz heaters and infrared heaters work according to this principle.
All radiant heaters direct heat to the objects or people to be warmed. For short periods of time (two to three hours), these heaters are more energy-efficient than convection heaters.
These heaters usually have a wattage rating of 1,500. The heating element, encased in quartz or a metal sheath, has a reflector panel behind it to direct the heat toward the objects. Some models will cycle off and on, but none have a thermostat. These heaters should have a tip-over device to automatically shut off the heater if tipped over.
The quartz rods will need to be periodically replaced, which can be done easily by snapping in a replacement rod.
A circular heater with no reflector warms the air, which rises and is distributed around the room (convection). A natural convection heater with no fan is one of the safest to use around small children because elements are almost completely enclosed; however, it does not give off as much heat as other supplemental heaters.
Convection heaters typically come in three types: baseboard, ceramic or fan-forced air.
* Baseboard beaters will warm a room well and have the added advantage of occupying unused space. Some have a fan. Most radiant baseboard heaters incorporate a thermostat. Convection heaters and models without a thermostat usually have two or three settings. Protective grills are removable for easy cleaning. Grills should have a close mesh, particularly if they are to be used around small children who may be able to push small objects or their fingers through large-meshed grill work.
* Ceramic beaters are small portable electric heaters that use a ceramic disk heating element. The heaters are ideal for spot heating because they are lightweight and easy to carry. These ceramic heaters are safer than other alternative heating sources because they operate at temperatures below the combustion point of paper. Ceramic heaters also include a washable filter to reduce air pollutants.
* Portable fan-forced air beaters come in models that operate on fuel oil, kerosene or propane gas, and can supply from 35,000 to 600,000 BTUs. They are used in work areas, such as garages and barns, and open areas such as construction sites.
Portable forced-air heaters use fuel and electricity to circulate hot air around the area to be heated. Their fans blow a gust of warm air that is able to heat an area that would normally be too open or drafty to heat with another type of heater. Models are equipped with air and fuel filters to block contaminants.
Safety features include automatic ignition systems and a flameout safety sensor, which turns the heater off in case of loss of combustion or lack of fuel.
The popularity of natural and LP gas space heaters continues to grow as consumers seek ways to trim their heating bills. Gas heaters are highly efficient and have low operating costs compared to similar electric and propane heaters. Gas heaters are available in vented or vent-free as well as radiant, circulating and catalytic models.
VENTED GAS HEATERS
The traditional gas heaters for supplemental heat require outside vents. Most of these are available in medium- or high-output models that range from 25,000 to 65,000 BTUs/hr. Most of these also include enclosed "radiating circulator" units with tempered glass in front of a series of radiants. Generally, a thermostat controls gas-vented heaters. These heaters are designed to take up minimum space.
VENT-FREE GAS HEATERS
Vent-free or unvented gas heaters are supplementary heat sources, since they require no vent. Like all gas appliances, the space should be properly sized for the unit.
All vent-free gas heaters are equipped with an ODS. The ODS shuts off the heater and the flow of gas to the burner if the oxygen level in the room becomes inadequate. The ODS is mandatory equipment for unvented heating equipment as specified by federal and voluntary standards.
Retailers must advise customers to strictly adhere to the manufacturer's safety instructions and to have the unit installed by a qualified professional. In addition, retailers should be sure all the vent-free products they carry meet or exceed indoor air quality standards or recommendations.
Infrared-radiant and convection are two types of vent-free gas heaters. The infrared-radiant units transfer most of their heat through direct infrared radiation from the heater to people and objects in the room. Most models feature ceramic radiants or panels that are positioned above the gas burner. Many of these units are open. The ignited gas gives off a bright orange glow that heats the occupants of the room. A screen-like guard protects the radiant plaques. However, the radiant plaques are not enclosed in the cabinet or behind glass.
Some vent-free radiant heaters have thermostats to efficiently maintain room temperature. Because the output from the vent-free heater is directed into the room rather than outdoors, these heaters are nearly 100 percent efficient.
Like infrared-radiant heaters, unvented or circulating convection heaters can be freestanding or mounted in a wall. This type of gas heater has burners enclosed within a painted or enamel-coated sheet metal housing that has air openings on the top, front and possibly the sides. Infrared-radiant heaters circulate heated air, making them suitable for heating larger areas to uniform temperatures.
Convection heaters work like a mini central heating system. Convection heaters first warm the air, which then warms the objects.
Natural gas and LP heaters are especially suited for zone heating, because they are clean burning, inexpensive to operate and many models require no venting.
Most residential kerosene heaters use a wick rather than a pressure-fed fuel system. Virtually all units offer automatic shut-off devices to extinguish the flame if the heating unit is bumped or jarred, and grills or guards to keep hands away from hot surfaces. Most models have push-button, battery-powered lighting devices that eliminate the need for matches.
Approximately 28 BTUs/hr. are required to maintain one square foot of space at 70[degrees] F. Multiplying this figure by the total square footage of a room gives the approximate BTU rating a model should have to heat the room.
Caution customers to use only K-1 clear kerosene fuel. Fuel that is yellow or colored will smoke, smell and hamper wick operation.
Since kerosene heaters deplete oxygen in the air and discharge carbon monoxide, some areas ban their use. Check with local government agencies to see if your community restricts kerosene heater use.
Some safety tips from the National Kerosene Heater Association include:
* Never use gasoline which, even in small amounts, creates the risk of flare-up and fire.
* Add fuel to the heater or cartridge tank out of the living area in a well-ventilated location.
* Never move, refuel or service the heater when it is operating or hot.
* Operate the heater only in well-ventilated areas.
* Keep heater more than 3' from materials such as furniture, clothing and draperies and out of high-traffic areas. * Extinguish heater before sleeping.
* Follow state and local regulations.
Baseboard heaters will warm a room well and have the added advantage of occupying unused space. Some have a fan. Most radiant baseboard heaters incorporate a thermostat. Convection heaters and models without a thermostat usually have a choice of two or three settings. Protective grilles are removable to facilitate cleaning. Grilles should have a close mesh, particularly if they are to be used around small children, who may be able to push small objects or their fingers through large-meshed grille work.
PORTABLE FORCED-AIR HEATERS
These heaters come in models that operate on fuel oil, kerosene or propane gas, and can supply from 35,000 to 600,000 BTUs. They are used in work areas such as garages and barns. Portable forced-air heaters use fuel and electricity to circulate hot air around the area to be heated. Models are equipped with air and fuel filters to block contaminants. Safety features include automatic ignition systems and a flame-out safety sensor, which turns the heater off in the event of loss of combustion or lack of fuel.
Ceramic heaters are small portable electric heaters that use a ceramic disk heating element. The heaters are ideal for spot heating because they are lightweight and easy to carry. These ceramic heaters are safer than other alternative heating sources because they operate at temperatures below the combustion point of paper. Ceramic heaters also include a washable filter to reduce air pollutants.
While not actually a source of supplemental heat, duct fans are designed to boost the flow of air from the central heating system to areas in a house that are hard to heat or cool. They overcome the added resistance in long duct runs, allowing warm or cool air to reach the "problem" room.
There are two types of duct fans: a prop fan that fits inside the duct or a squirrel cage fan with the motor mounted outside of the duct. Most models will vent around 200 cfm in 6" to 8" diameter ducts. Duct fans can be wired in series with the central furnace blower or operated by an auxiliary thermostat.
OUTDOOR WOOD FURNACE
Another alternative heating source that has been gaining popularity is an outdoor wood furnace, which is installed outside and works with any existing heating system.
Heated water is pumped to the home or building through insulated underground tubes. Heat exchangers or direct circulation convey the heat into a forced-air furnace, boiler or radiant floor heating system. This allows for normal thermostatic control of temperature for safe, even and comfortable heat.
Safety Tips for Electric Heaters
* Only operate electric heaters listed with a nationally recognized testing laboratory such as UL.
* Be sure to purchase a heater with a guard around the heating element. This will keep fingers or fabrics from touching the hot element.
* Always read and follow operation and maintenance instructions before operating a heater.
* Only use a heavy-duty extension cord, #14 gauge or larger. It is better to not use an extension cord at all
* Never run the heater's cord under rugs or carpeting.
* Do not leave the heater unattended and do not operate while sleeping.
* Always keep portable electric heaters away from water and never touch an electric heater if you are wet.