Abstract
This experimental study is carried out to investigate reliability and effectiveness of a new method of using photo-coupler for detecting frost formation in an air source heat pump, and further to determine the most efficient initiation point of the defrost cycle. This new method of using photo-coupler as a frost sensing device is evaluated by comparing its performance with conventional time control defrost system in which defrost cycle is set to start at predetermined interval, e.g. about at every 1-1.5 h. Results indicate that overall heating capacity of photo-coupler detection method (case IV) is 5.5% higher than that of time control method. It is also shown that for maximum efficiency the defrost cycle must be initiated before the frost build-up area exceeds 45% of total front surface of the outdoor coil.
| Original language | English |
|---|---|
| Pages (from-to) | 191-198 |
| Number of pages | 8 |
| Journal | International Journal of Refrigeration |
| Volume | 29 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2006 Mar |
All Science Journal Classification (ASJC) codes
- Building and Construction
- Mechanical Engineering