Derek Cole explains the loud noise from heat pumps in cold weather: it's the defrost cycle, where the system reverses to melt frost on the outdoor unit. Emergency heat uses three times more electricity, so let the defrost cycle run unless the unit is completely iced over.
When it goes into defrost and it has to go on that cycle, it actually reverses the flow of refrigerant. So instead of being in heat mode, it switches to AC mode and it turns on those heat strips so you don't get cold in the house. So the reason it makes that loud noise is all that gas and refrigerant is saying, "Brrr," back the other way. So that is the noise you're hearing. A lot of folks don't know that and probably don't need to know that, but it's actually going into AC mode because it's burning off the frost on the outdoor unit. So it's actually taking the heat that's in the house and blowing it back outside like it was summertime. So that's how you melt that frost. So it does make kind of a loud noise, especially if it's at the bedroom or wherever the outdoor unit is. It will probably wake you up or at least until you get used to it, wake you up. But it's nothing to worry about. And some folks have asked too, you know, when it's really cold outside, should I just turn my unit to emergency heat only? And the answer is no, do not do that. There's still heat in the air. The heat pump can still function with the emergency heat. If you go straight to emergency heat, that is 3 times more expensive than regular heat. So that is not a good option unless that unit is just packed with snow and ice and you can't get to it and it can't defrost. And that's a good reason. But to have the unit work less by not having to go to defrost cycle is actually going to cost you more money. So Just a little tidbit there, but the noise is the defrost cycle.
How to Prevent Mold and Odor in Your Air Conditioning System with UV Light #shorts
