Heat Pump Question

[joemach]

My brother has a Lennox heat pump (sorry no Model or Serial #) about 10 years old, with a 3 ton condenser and a 4 to air handler. He asked a question as to why the temp in the winter coming out of the vents seems to modulate so much. He says it goes anywhere from 85* to 110* F. Seems to start out at higher temp and the more it runs, the lower the temp goes. I have not had a chance to look at it yet.

Any idea what might be going on with this system. He lives out of town but I will be over to see him next weekend.

Thanks for any help.

[RyanHughes]

With temps around 110* plus, the electric heat elements ("auxiliary" heat) could be active during those periods of time to meet the temperature differential quicker. Also, outdoor temperature will affect the air temperature coming out of the registers.

[joemach]

Hey Ryan - thanks

You make a good point. Must be having brain meltdown from working on a/c last few months. I should have know about heat strips coming on to meet demand.

[BaldLoonie]

Depends on outdoor temp and frost buildup on the coil too. But to get 110° air, likely the strips.

[joemach]

Me thinks you are right.

Thanks