How to save more energy in multi-families.

The installation of a new boiler and new windows are important first steps toward maximizing the energy efficiency of a multi-family dwelling. However, owners and managers can do much more to eliminate excessive consumption of fuel oil and/or natural gas at their buildings.

One of the major causes of fuel waste is the overheating of apartments due to inadequate control of boiler cycling. At many buildings in this area, boiler operations are controlled by a timer mechanism, which cycles a boiler on whenever the outside temperature falls below a statutory level (55 degrees F. daytime in New York City), and does not turn it off until the outside temperature rises above the turnon point.

Since a timer does not respond to changes in inside temperatures, the boiler continues to cycle on cold days even after apartments are far too hot for tenants' comfort.

To solve this problem, Adbar Realty, a Long Island based management firm, has replaced the timers at eight apartment buildings it owns and manages in the Bronx and Washington Heights with OAS Heat Computers. These automated systems have reduced fuel consumption substantially at all eight buildings by eliminating overheating and restricting boiler cycling to periods when tenants actually need heat and/or domestic hot water.

Much Lower Natural Gas Bills

As an example of the resulting energy savings, Robert Spring, a partner in Adbar Realty, cites a 21.5 percent reduction in gas consumption at a 104-unit apartment building in the Bronx.

"We maintain inside temperatures at 73 degrees F. during the heating season. During the year prior to the installation of the OAS Heat Computer, the building's annual natural gas consumption was 81,436 cc's. After the computer was installed, the annual consumption, adjusted for outside weather conditions, was 63,956 cc's. That is a saving of 17,480 cc's. The reduction in our fuel bills that year alone more than paid for the OAS Heat Computer," Mr. Spring said.

To a certain extent, these energy savings reflect the fact that the control of boiler cycling is transferred from the building superintendent to the OAS Heat Computer.

"At one of our buildings, the super would turn up the heat before he went off the job on weekends to avoid the possibility of tenant complaints. As a result, the apartments became uncomfortably hot and tenants began to use their windows as thermostats by opening and closing them to regulate the temperature," Mr. Spring said.

Remote Control

By dialing the OAS Heat Computer from his office, or any other location where there is a telephone, Mr. Spring can monitor and/or change apartment and domestic hot water temperatures.

A phone call to the computer also provides Adbar Realty with a report over the preceding 24-hour period on inside, outside and domestic hot water temperatures; unauthorized system overrides; and system malfunctions, such as flame failure, excessively high stack temperature, and excessive water consumption.

Also, the system provides on demand a daily record for the last two weeks of total daily burner run time, oil and water consumption, and high and low outside temperatures.

By scanning the computer printouts, Mr. Spring or an employee can manage the heating system by noting any parameter that departs from the norm. The indicator can be analyzed and any necessary maintenance can be scheduled.

Water Leak Detected

For example, a review of the printouts from a recently installed Heat Computer at an Adbar Realty building a water leak of about 800 gallons a day from an underground return line.

"The pipe was porous and leaking at a number of points, and had to be dug up and replaced, but we were not aware of the problem until it was detected by the OAS Heat Computer," Mr. Spring said.

The 72-hour printout is particularly useful in case a tenant calls Adbar Realty with a heat or hot water complaint. Even if the complaint refers to a problem that occurred hours-or even days before, including nights and weekends, it can be verified by checking the printouts.

If there is no cause for the complaint, or if the problem that caused it is already being corrected, the printout helps explained matters to the tenant's satisfaction.

It is, of course, possible that a tenant, for personal reasons, might carry an unjustified complaint to a municipal regulatory agency. If so, an OAS Heat Computer printout can be submitted as evidence to answer the complaint. It was accepted as such in the case of a no-heat violation issued to another management firm by die New York City Office of Code Enforcement. The computer printout showed that, due to a power failure, the boiler in the building wasn't operating prior to the time the building was inspected. The violation was dismissed.