Frost retardation of an air-source heat pump by the hot gas bypass method

Ju Suk Byun, Jinho Lee, Chang Duk Jeon

Research output: Contribution to journalArticlepeer-review

83 Citations (Scopus)


This study is concerned with a hot gas (refrigerant) bypass method to retard the formation and propagation of frost in an air-source heat pump. The feasibility of the hot gas bypass method was investigated experimentally and the method's performance is compared with that of a normal, 1.12 kW capacity air-source heat pump system with no defrost equipment such as an electric resistance heater. Results indicate that the hot gas bypass method is useful for retarding the formation and growth of frost at the outdoor coil. The best performance is shown under a bypass refrigerant flow rate of 0.2 kg/min (20% of the whole system refrigerant flow rate). During 210 min of heat pump operation, the hot gas bypass method improved COP and heating capacity at an average of 8.5% and 5.7%, respectively, relative to the normal system.

Original languageEnglish
Pages (from-to)328-334
Number of pages7
JournalInternational Journal of Refrigeration
Issue number2
Publication statusPublished - 2008 Mar

All Science Journal Classification (ASJC) codes

  • Building and Construction
  • Mechanical Engineering


Dive into the research topics of 'Frost retardation of an air-source heat pump by the hot gas bypass method'. Together they form a unique fingerprint.

Cite this