Field performance of an energy pile system for space heating

• Published in: Energy and buildings Vol. 39; no. 5; pp. 517 - 524
• Main Authors: Hamada, Yasuhiro, Saitoh, Hisashi, Nakamura, Makoto, Kubota, Hideki, Ochifuji, Kiyoshi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2007; Elsevier
• Subjects: Applied sciences; Building technical equipments; Buildings; Buildings. Public works; Earthwork. Foundations. Retaining walls; Energy; Environmental engineering; Exact sciences and technology; Friction pile; Geotechnics; Geothermal energy; Ground Source Heat Pump; Natural energy; Space heating; Underground heat exchanger; Ventilation. Air conditioning; Asia; Japan; Japan, Hokkaido, Sapporo; Underground heat exchanger; Friction pile; Ground Source Heat Pump; Air conditioning; Performance evaluation; Pile foundations; Heat pump; Buildings; Heat exchanger; Geothermal energy; In situ test; Heating load
• ISSN: 0378-7788
• DOI: 10.1016/j.enbuild.2006.09.006

This paper describes the field performance of air conditioning with an energy pile system, which was applied to the pile foundations of an actual building for the purpose of reducing the cost of the underground heat exchanger. First, the building for both office and residential use, for which a space heating and cooling system using friction piles was installed, was built in Sapporo in December 2000. Second, three tests were carried out to specify the design of a heat exchanger inside the pile, and a U-tube type underground heat exchanger was adopted from the viewpoint of energy efficiency and installation costs. Long-term space heating operation measurements indicated that the seasonal average temperatures of brine returning from the underground and pile surfaces were 2.4 and 6.7 °C, respectively. The average coefficient of performance for space heating was quite high at 3.9, and the seasonal primary energy reduction rate compared with a typical air conditioning system reached 23.2%.