Insulate hot parts on outdoor unit of air to air heat pump

Outdoor unit, starting to add insulation

There are several hot parts in the outside unit of an air to air heat pump. This heat is basically lost, but most of it can be retained if properly insulated. This advice is valid in climates where the heat pump is used for heating during the winter, and not so often used as air-conditioner during the summer.  After reading about this topic at the Norwergian http://www.byggebolig.no forum I decided to do this on our Panasonic CS-CE7GKEW. There are claims of adding another 500W additional heat from the indoor unit during cold days. I have a small heatpump already partially insulated, so it might be more like 200W, but it sure will make a good pay off compared to the minimal cost of some insulation.

So I turned off the air to air heat pump unit, and opened up the outdoor unit using a screw driver. Some pipe insulation were already in place from Panasonic, but there were also pipes that were exposed and warm to the touch.

Insulation poking on outdoor unit

Extra inside insulation completed

I got a sheet of insulation and tore off small pieces that I poked lightly in between all the pipes, leaving an inch free at the bottom where there might be water collecting during the winter. Some pipes are cold and do not really need insulation, but adding will also insulate them from cooling the warmer pipes. So I just filled up nicely between the pipes. On the top I added som layers of insulations, but not covering the transformer in the upper left corner of the picture. I do not know, but it might get hot, and electronics are happier when cool. On the right side of the picture you can see that I have also added insulation where the two pipes connect to the indoor unit. The pipes itself do also benefit from more insulation, so I added some there as well, covered by some plastic to keep rain out. I have a roof covering the outdoor unit, so this should be sufficient for weather proofing.

Summary in Norwegian: Utendørsdelen på en luft til luft varmepumpe har mange varme rør som har lite eller ikke noe isolering. Ved å fylle på med isolasjonsmatriale kan man unngå dette varmetapet. Det vil da istedet komme til nytte som levert varme til innedelen.