I have a heat pump and this morning I was thinking about it's efficiency.
The pipe/tubing insulation is on the thicker of the two lines and it goes from the exterior of the air handler to the exterior of the condenser. Looking through the fan blades on the condenser, I can see the thick tubing continuing to the reversing valve - there is about 1 ft. of tubing there. After the reversing valve, up to the compressor itself, there is another 10 inches of tubing.
So, when the HP is running, there is almost 2ft of tubing that sits outside in cold temperatures and inside of a metal box that is even colder (it is basically air conditioned).
Is there any problem with insulating the thicker tubing inside the condenser box? I bet I am losing 5-10 degrees right there (when it is, say, 35* outside).
Does it also make sense to insulate the thin tubing (for A/C) because of the same issue in the summer?