Air-to-air or air-to-water heat pumps in cold, humid conditions periodically run defrost to remove frost from the outdoor coil to restore what?
Choices
- (A) Hot gas to domestic tank only
- (B) Heat transfer and airflow through the outdoor coil, avoiding excessive head/ poor COP
- (C) Foundation bearing
- (D) Duct R-value
Correct answer: (B)
Heat transfer and airflow through the outdoor coil, avoiding excessive head/ poor COP
Explanation
Defrost: reverse, resistive, or off-cycle per OEM — restore UA and flow.