Data, exergy, and energy analysis of a vertical-bore, ground-source heat pump to for domestic water heating under simulated occupancy conditions

• Published in: Applied thermal engineering Vol. 89
• Main Authors: Ally, Moonis Raza, Munk, Jeffrey D., Baxter, Van D., Gehl, Anthony C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier 27.05.2015
• Subjects: Exergy; GEOTHERMAL ENERGY; ground-source; heat pump; renewable energy; sustainability; thermodynamics
• ISSN: 1359-4311

Evidence is provided to support the view that greater than two-thirds of energy required to produce domestic hot water may be extracted from the ground which serves as renewable energy resource. The case refers to a 345 m2 research house located in Oak Ridge, Tennessee, 36.01 N 84.26 W in a mixed-humid climate with HDD of 2218 C-days (3993 F-days) and CDD of 723 C-days (1301 F-days). The house is operated under simulated occupancy conditions in which the hot water use protocol is based on the Building America Research Benchmark Definition (Hendron 2008; Hendron and Engebrecht 2010) which captures the water consumption lifestyles of the average family in the United States. The 5.275 (1.5-ton) water-to-water ground source heat pump (WW-GSHP) shared the same vertical bore with a 7.56 KW water-to-air ground source heat pump for space conditioning the same house. Energy and exergy analysis of data collected continuously over a twelve month period provide performance metrics and sources of inherent systemic inefficiencies. Data and analyses are vital to better understand how WW-GSHPs may be further improved to enable the ground to be used as a renewable energy resource.