Avoiding heat pump evaporator frosting through the use of desiccants
- Electric Power Research Inst., Palo Alto, CA (United States)
- Drexel Univ., Philadelphia, PA (United States)
- S.R. Steel, Bombay (India)
Frost formation and the required defrosting is a major problem affecting air-source heat pumps operating under high ambient humidity conditions. It is claimed that the impact of frost can lower the heating efficiency by as much as 20%. If the moisture contained in the air flowing across the evaporator of the heat pumps could be eliminated or reduced, frosting would not occur. This project was undertaken to determine whether frost formation can be reduced or avoided by reducing the moisture in the air-stream passing over the evaporator by means of desiccants. A special test facility was constructed and tests were conducted with saturated air at frost promoting temperatures. Desiccant matrices were placed ahead of the evaporator and the times for coil frosting with and without desiccants were compared. It was found that the use of desiccants prevents coil frosting but only for a limited time. A method for regenerating the desiccant must be developed to make this concept commercially viable. This is to be accomplished in a second phase of the project.
- OSTI ID:
- 113291
- Report Number(s):
- CONF-950336--; ISBN 0-7918-1300-2
- Country of Publication:
- United States
- Language:
- English
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