Field monitoring of a variable-speed integrated heat pump/water-heating appliance
- National Inst. of Standards and Technology, Gaithersburg, MD (United States). Building and Fire Research Lab.
A variable-speed integrated heat pump/water-heating appliance was monitored for two years while meeting the space-conditioning and water-heating needs of an occupied residence. Experimental results are presented that show the total energy consumed by the residence was significantly reduced compared to previous years in which electric base-board heat, a wood stove, and window air conditioners were used. During the two space-heating seasons, the variable-speed integrated heat pump/water-heating appliance used 60% less energy than would have been consumed by an electric furnace with the same air distribution system and a storage-type electric water heater. The monthly space-cooling-only coefficients of performance (COP) ranged from 2.50 to 4.03, whereas the monthly space-heating-only coefficients of performance ranged from a low of 0.91 to a high of 3.33. A proposed index to quantify the overall system performance of integrated water-heating/space-conditioning appliances, referred to as the combined performance factor, ranged from 1.55 to 3.50. The majority of larger values occurred during months in which space cooling dominated. The combined performance factor for the entire two-year study was 2.45. A conventional watt-hour meter supplied by the local electrical utility and an electronic digital power analyzer were used to measure the energy consumption of the variable-speed heat pump to discern if variable-speed equipment introduces errors in conventional utility metering equipment. Measurements made using the two instruments were in excellent agreement. The monthly energy consumption and peak electrical demands of the residence, integrated heat pump/water-heating appliance, supplemental space heater, and water heater are discussed. The influence of outdoor temperature on electrical power demand is presented.
- OSTI ID:
- 211792
- Report Number(s):
- CONF-950624-; TRN: IM9617%%108
- Resource Relation:
- Conference: Annual meeting of the American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc. (ASHRAE), San Diego, CA (United States), 24-28 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of ASHRAE transactions 1995: Technical and symposium papers. Volume 101, Part 2; PB: 1497 p.
- Country of Publication:
- United States
- Language:
- English
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