Houzz Logo Print

heat pump blows frigid air during defrost

8 years ago

I live in Massachusetts and I recently had a Bryant Evolution Extreme 2 ton heat pump installed to provide my heat and A/C. It does not have a heat strip or any other backup source. Since the weather started getting cold 3-4 weeks ago I've discovered that during the defrost cycle it blows very cold air. I understand that as designed during defrost the heated air will be diverted from the interior to the heat pump, and I'll probably need to add a heat strip which will turn on when it defrosts. But I've had air as cold as 27 degrees coming from my vent (outside temperature was teens to twenties). This causes the room temperature to decrease, and then the system generates heat again, then it defrosts and the room gets cold - it's an endless cycle. With air that cold I wonder if the heat strip would even be able to increase the temperature enough to make a difference. The installer thought it might be because my ducts are in the attic and as soon as the air is no longer being heated it instantly gets cold from the attic air. But I did a test where I turned off the heat pump and just ran the fan to recirculate the air, and the air coming out was room temperature - as I would expect.
Just wondering if anyone else in a similar climate has experienced frigid air during the defrost cycle, and what was done to solve it. Thank you.

Comments (12)