Air to air heat pump modifications

[Vekke]

I have bougth 2 heat pumps this year and will propably buy the 3rd later this year. As some of you know I live in finland where its really cold in winter. I still did not want to spent big bucks to nordic climate heat pumps. I bougth best I could afford ones Panasonic KIT CS-FZ35WKE. It worked well on temps when it was maximum of -10 celsius but it started to freeze the outer unit slowly but steadily. I knew that it will happen and I have to install a heating cable to the outer unit, Which I did a 35w 2 meter long cable.



That boosted little bit the performance and it now worked well to around -15 celsius, but if it get colder than that inside temps started to drop. Well my house is pretty big which is one reason. I measured outer unit temperatures and noticed that the stock insulation in the pipes and connectors were not good. I added more insulation materials on the outer unit walls in made double insulation to coolant pipes.




After those mods the impact to heating was big. Not inner unit max temps get +10 celsius hotter and its able to keep inside temps on +20 celsius to aroung -20 celsius. Pump did not newer shut down even at -35celsius but it did not make any heat either at those temps so more work is ahead.

[freebeard]

It's hard to tell from the close-up pix, is that a cover in the upper left?

A proper wind shield could reduce the wind chill effect.

[cRiPpLe_rOoStEr]

Originally Posted by freebeard

A proper wind shield could reduce the wind chill effect.

A removable one does the trick for the Citroën 2CV and the Aero Boero AB-115, decreasing the cold air flow around their oil coolers during winter.

[Isaac Zachary]

Just to be clear, you'd want all the air you can get to the evaporator. Low pressure lines can also be let out in the open (when used for heating only) since they will always be colder than ambient temperature, with or without wind chill. The only problem is you'll get ice build up on them if you do. But yes, the more you cover up the high pressure lines the better.

[Vekke]

There is a external roof/shelter which have big a hole where it can blow the air out freely. It protects the unit for snow that falls down from the house roof.

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

The only problem is you'll get ice build up on them if you do.

Even though heat pumps seem to not be so much of rocket-science, I guess it would be a PITA having to work around some de-icing

[maanma]

One could improve performance in very cold weather with car radiator behind pump circulating liquid from underground pipes.

Another is lead all exhaust air from house inside to rear side of pump.

[freebeard]

OEM car parts are economical, but the buried pipes, not so much. The problem isn't the unit as a whole, just the heat exchanger/condenser. Ice blocks the air flow.

[cRiPpLe_rOoStEr]

Originally Posted by freebeard

OEM car parts are economical, but the buried pipes, not so much.

Repairing buried pipes is often a PITA too.

[freebeard]

....when they are laid out like a septic field just below the surface.

A bore hole has a vertical element that could be winched out if needed.


http://www.brightgreenhomes.co.uk/for-home/heat-pumps/