Comparison of the heating performance of air-source heat pumps using various types of refrigerant injection

Jaehyeok Heo, Min Woo Jeong, Changhyun Baek, Yong Chan Kim

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79 Citations (Scopus)


The performance degradation of air-source heat pumps cannot be avoided when they operate at both very low and high ambient temperatures. The refrigerant injection technique has rapidly developed in recent years due to its outstanding performance at low ambient temperatures. This study measured the heating performance of air-source heat pumps in which novel vapor injection techniques of a combined flash tank and sub-cooler (FTSC) cycle and a double expansion sub-cooler (DESC) cycle were applied. The performance of these cycles was compared with that of a flash tank (FT) and a sub-cooler (SC) cycle. The average heating capacities of the FT, FTSC, and DESC cycles were higher by 14.4%, 6.0%, and 3.8%, respectively, relative to that of the SC cycle, but the average COPs for the respective cycle options were very similar.

Original languageEnglish
Pages (from-to)444-453
Number of pages10
JournalInternational Journal of Refrigeration
Issue number2
Publication statusPublished - 2011 Mar 1



  • Heat pump
  • Performance-heating
  • System injection
  • Two-stage

ASJC Scopus subject areas

  • Mechanical Engineering
  • Building and Construction

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