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Author
Fanney, A. H. | Dougherty, B. P.
Title
Performance of a Residential Desuperheater.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD
Journal
ASHRAE Transactions, Vol. 98, No. 1, 489-499, January 1992
Sponsor
Department of Energy, Washington, DC
Report
3588,
Book or Conf
American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. (ASHRAE). Winter Annual Meeting. January 29, 1992, Anaheim, CA, 1992
Keywords
heat pumps | heating | water | residential buildings | desuperheater | instruments
Abstract
The performance of a residential earth-coupled heat pump having an integral desuperheating water-heating circuit is presented. The system, which includes a 50-gallon electric water heater, is located in a home in Gaithersburg, Maryland. During a 24-month monitoring period, the desuperheater contributed 27% of the total energy supplied for heating water. On a monthly basis, the desuperheater's contribution varied from less than 1% to 55%. Simple payback for the desuperheater is projected to occur by the end of the fourth year of operation. For a few selected days during the monitoring period, data were recorded every minute to gain insight into how the desuperheater and resistive elements interact in recovering the water heater. In general, the desuperheater contributed most to heating the lower portion of the tank from the setpoint of the lower thermostat, 110 deg F, to temperatures occasionally approaching 140 deg F.