How Cold? (heat pump)

[reedbr]

What is the lowest temperature that a reverse cycle A/C (aka heat pump) will be effective down to?  I tried running one yesterday, but water in the line must have been frozen overnight.  Somebody else told me they wouldn't really work below 44 degrees anyway.  I don't know where they picked that number up from.  Does anybody have experience or spec's on this?

Thanks.

[Bob Kuba]

I moved my boat from Cleveland to Chicago early last spring, and the water temperature at the Presque Isle, Mi harbor was down around 38 degrees one night. The reverse cycle heat pump on our a/c unit kept the cabin a cozy 72 degrees all night. I don't understand how you could get any heat out of water that is 38 degrees, but my crew was sure happy!

Bob K.

[Stu Jackson]

Bob

The way you get heat out of 38 degree water in the winter is the same way you get cooling out of your heat pump on your boat (or your car's air conditioner) when it's 95 or 100 degrees outside during the summer.

Only backwards...

[jentine]

Heat pumps have a break-even point at about 40 degrees, Farenheit.  Generally they also have an electric heat supliment to provide heat when the temperature is too low.
Jim