PO-86-09-3 -- Combination Water-Heating/Space-Heating Appliance Performance PDF

During the last few years, combination (or integrated) water-heating/space-heating appliances have made a successful entry into the residential market. Multifamily dwellings have been the most suitable place for their application. This paper presents the water-heating and water-heating/ space-heating performance of the combination appliances under actual conditions of use in the field, along with the laboratory tests that support the findings of the field performance. In the laboratory, a method of rating the performance of a combination appliance was established. For laboratory tests, a combination appliance consists of a gas-fired storage water heater, or a hot water boiler with a secondary tank, and an air handler.

Field tests were conducted on six residential sites. Water-heating performance was established by evaluating hot water usage data during summer months. Water-heating/space-heating performance was established by using residential hot water use data and the amount of hot water circulation for space heating during winter months. Data were collected at intervals of approximately two weeks. Analysis of data indicated that the noncondensing combination residential appliance produces hot water at an efficiency in the range of 47% to 58% for water heating during summer months and produces hot water at an efficiency in the range of 51% to 79% for water-heating/space-heating performance during winter months.

In the laboratory, simulated field condition tests supported the field test results. Also, a methodology was developed to rate the combination appliance as a water-heating/space-heating appliance, including the establishment of annual fuel utilization efficiency, seasonal efficiency, and annual space-heating energy consumption.

Units: Dual