Energy performance of air-to-water and water-to-water heat pumps in hotel applications

Joseph C. Lam, Wai Hung Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

24 Citations (Scopus)


We present work on measurement of the energy performance of heat pumps for hotel operations in subtropical climates. Two city hotels in Hong Kong were investigated. The first case was an application of an air-to-water heat pump to provide heating for an outdoor swimming pool during the heating season. The second case was the installation of three water-to-water heat pumps to complement an existing boiler system for hot water supply. The heating energy output and corresponding electricity use were measured. The heat pump energy efficiency was evaluated in terms of the coefficient of performance (COP), defined as the heating energy output to the electrical energy use. The air-to-water heat pump provided 49.1 MWh heating while consuming 24.6 MWh electricity during the 612-month heating season from mid-October to April. For the water-to-water heat pumps, the estimated annual heating output and the electricity use were 952 and 544 MWh, respectively. It was found that the heat pumps generally operated in a COP range of 1.5-2.4, and the payback period was about two years, which was considered financially attractive.
Original languageEnglish
Pages (from-to)1625-1631
Number of pages7
JournalEnergy Conversion and Management
Issue number10
Publication statusPublished - 1 Jun 2003


  • Air-to-water heat pump
  • Coefficient of performance
  • Hotels
  • Subtropical climates
  • Water-to-water heat pump

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Fuel Technology
  • Nuclear Energy and Engineering
  • Renewable Energy, Sustainability and the Environment

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