Computer systems are being used increasingly to control and monitor the use of electrical energy to heat and cool office buildings.

Essentially, these systems manage energy resources through centralized controls, using mostly plain language commands, on large energy-consuming devices.

One broad-based area firm, the Donohoe Companies (builders, developers and realtors), now is using using its wholly owned subsidiary, Complete Building Services, which has a computer system, to reduce energy use in buildings in which the parent firm has an ownership interest. CBS also has a capacity to install a program to do the same job for individual client buildings.

"Our system (called Solid State) really does two things," said Joseph E. Widmayer, vice president of engineering and head of CBS. "It saves money for bulding owners and energy resources for the nation. We consider it a valuable tool in building operation and maintenance."

In addition, the system has been programmed to turn parking light lights on and off, to unlock building doors in the morning and lock them in the evening and to monlitor malfunctions of mechanical equipment.

"By employing a schedule of power consumption established with the client, the system enables devices to be turned off in a pre-arranged, user-selected sequence," said Widmayer.

Another effort in the same direction was taken recently by the Braedon Companies, which leases office buildings. James Eichberg, president of Braedon, said that a forum was held on electrical usage in office buildings. A representative of Pepco was present to discuss how energy awareness and conservation are used to maintain a property's economic viability. Eichberg said that innovative energy-saving devices, including competerized systems, were discussed.

An efficient monitoring system, according to Widmayer, usually saves a minumum of 16 per cent of the total energy consumption in a large building. "Power companies normally charge for electricity on the basis of the amount of energy used and the highest demand required. Cycling of devices consuming large amounts of power reduces total energy consumption and cutting back on certain devices at pre-selected times enables the peak load to be lessened, Widmayer said.

He added that the heating target usually is 70 degrees and the cooling goal is 76 degrees. "Sometimes we can save an hour's use of the chilling equipment in late afternoon by cutting off the chiller and using the fan to keep air in circulation," he added.

Since the computerized equipment was installed late last year by CBS in thenew Donohoe headquarters in the basement level of a new Holiday Inn (scheduled to open soon) at 2101 Wisconsin Ave. NW., the system has been used to monitor four area buildings. Two are in upper Bethesda and two in the District.

Widmayer said that a suburban shopping mall with office space and a new downtown building soon will be added to the service.

Complete Building Services chose equipment of Solid State Systems, Marietta, Ga., for its energy management service. However, several other competing systems are also being used by other firms in this area.

Widmayer commented that CBS, which offers both mechanical and cleaning services to building clients, became aware of the rising cost of energy four years ago and inaugurated a program of manual controls of power use.

"Then we became aware that Abe Pollin was using a computer system successfully to control energy use at his vast Capital Centre. We investigated and decided to get involved. So far, we are getting evidence of savings that make it worthwhile," Widmayer summarized.