Applications Tests of Commercial Heat Pump Water Heaters

Abstract

Field application tests have been conducted on three 4 to 6-ton commercial heat pump water heater systems in a restaurant, a coin-operated laundry, and an office building cafeteria in Atlanta. The units provide space cooling while rejecting heat to a water heating load. The tests, conducted for Georgia Power Company, examined both quantitative and qualitative aspects of the heat pumps and the overall water heating systems. The results provide valuable insight into the actual operating characteristics of heat pump water heaters and useful guidelines for system design and operation. The capacity and efficiency of the units agreed with manufacturers' specifications. COP values ranged from 2 .6 to 3.0 for water heating only, and from 4.1 to 5.0 when space cooling benefit was included. It was concluded that heat pump water heaters can provide economical water heating and space conditioning. However, application sites must be selected within certain constraints and a minimum level of operating control and maintenance must be observed.