Reprinted from the June 1988 issue of
CASE STUDY/ENERGY CONTROL SYSTEM
Olympia Centre, Chicago, IL... A weather‑based energy control system automatically adjusts building temperature and lowers heating costs Olympia Centre For commercial office buildings, the annual cost of electric heating is a very important consideration. To help reduce its heating bill, the distinctive Olympia Centre in downtown Chicago incorporated a weather‑based energy control system to automatically regulate the heating output in the commercial office space.
The 63‑floor Olympia Centre is a multi‑use facility offering retail, luxury office and residential space in one building. It is owned and managed by Olympia & York Companies.
The building's first four floors house a Neiman‑Marcus department store, which occupies 200,000 square feet. The next 18 floors accommodate luxury commercial offices. These floors range in area from 16,000‑18,350 square feet. The top 38 floors are devoted to residential condominiums.
The retail floors have variable air volume heating with in‑line duct electric heaters. The residential floors employ convectors in baseboards located below the windows.
In contrast, the 18 commercial office floors feature radiant heating panels mounted above each window. Their operation is controlled by the PACER, Weather‑Based" heat control system. 'together, the radiant heating panels and the PACE system create a "thermal barrier" around the more than 300,000 square feet of office space.
The system maintains an economical steady‑state comfort level inside the offices by replacing heat at the same rate it is lost from the building. It automatically compensates for the effects of temperature, wind, solar gain and rain by monitoring data from electronic sensors mounted on Olympia Centre's exterior walls.
Continuous computation of energy data.
The data from the exterior sensors is fed back to the master control panel, which continuously recomputes the percentage of heating capacity needed to match the outdoor conditions. The master control panel activates SCR power controllers which, in turn, regulate the wattage to the radiant heating panels.
With many traditional heating systems, the heat is either completely on or off. This system, however, keeps the heat on but only in the degree needed for the weather conditions.
Heating costs are kept low because the system constantly maintains the thermal barrier around the building. This can result in savings of up to 40 percent in operating costs, while still providing superior comfort due to the steadystate operation. The system can BUILDING OPERATING MANAGEMENT save 30‑40 cents per square foot on electricity costs.
"The system has provided excellent service since it was installed," says Larry Kenny, Olympia Centre building manager. The solid‑state electronics used in PACE provide this reliable operation and can virtually eliminate maintenance costs and expensive downtime.
Independent of cooling system
PACE requires no interior thermostats and work independently 4Olympia Centre's cooling system. .No control interlock is required because the thermal barrier has a lower temperature than the setting of the interior cooling‑only thermostat. So, there is no overlap for "fighting") between perimeter heating and interior cooling.
The system also controls the heat output on each building face in response to solar gain. Each building face is divided into upper and lower zones with separate solar sensors. As direct and reflected sunlight strikes each zone, the system reduces the heat output accordingly. This produces additional energy savings with no sacrifice in comfort in any zone.
According to an Olympia & York spokesperson, the company has received no calls or complaints from the office tenants regarding the heating system. Current occupancy rate for the commercial office space is about 73 percent.
"Because it works so well, tenants and building owners and managers seem to forget all about PACE," says Jerry Muhlenberg, GEEI's national sales manager. "'Tenants are comfortable in all weather conditions, operating personnel get fully automatic heating control, and owners receive much lower monthly electric bills."
GENERAL ELECTRONIC Enterprises, INC.
132 WEST MAIN STREET ‑ RAHWAY, NJ 07065 ‑ (732) 381-1144