Field study of heating performance of three ground-source heat pumps in Canadian single-family houses

• Published in: Energy and buildings 2021-09, Vol.247, p.110959, Article 110959
• Main Authors: Abdel-Salam, Mohamed R.H., Zaidi, Aqeel, Cable, Matt
• Format: Article
• Language: English
• Subjects: Climate; Coefficient of Performance (COP); Cold weather; Compressors; Cooling; Energy savings; Ground-source heat pump; Heat; Heat exchangers; Heat pumps; Heating load; Houses; Operating costs; Operational problems; Peak load; Power consumption; Residential buildings; Seasons; Space heating
• ISSN: 0378-7788; 1872-6178
• DOI: 10.1016/j.enbuild.2021.110959

This paper is the second part of a two-part study on the performance of ground-source heat pumps (GSHPs) in single-family detached houses in Canada. In Part I the cooling performance of two GSHPs was tested, analyzed and evaluated over one cooling season. In this paper, the heating performance of three vertical closed-loop water-to-air GSHP systems installed in three new single-family detached houses in Innisfil (80 km north of Toronto, Canada) is monitored, analyzed and evaluated over one heating season. Results show that GSHP A, GSHP B and GSHP C were able to meet the peak heating load without using the auxiliary heating element. The seasonal coefficient of performance of heat pump of GSHP A, GSHP B and GSHP C is 4.2, 4.0 and 3.4, respectively, whereas the seasonal coefficient of performance of the GSHP system of GSHP A, GSHP B and GSHP C is 3.8, 3.4 and 2.7, respectively. GSHP A has the highest COP mainly because it is equipped with a variable speed compressor while GSHP B and GSHP C are equipped with two-stage compressors. The average temperature of water leaving the ground loop of GSHP A, GSHP B and GSHP C is 3.9 °C, 3.1 °C and 2.7 °C, respectively, where the average temperature of water leaving the ground loop varied by up to 6.3 °C throughout the heating season. The total power consumption and operating cost of GSHP A, GSHP B and GSHP C are less than conventional air-source heat pumps by up to 46%, 40% and 24%, respectively. It is concluded that GSHPs operate at high COPs without operational problems even in very cold climates if designed, sized and installed correctly.