Alan wrote:

Thanks, I often wondered about the efficiency of running A/C heat pump
systems all year to heat and cool a building as required.

It works well in places with mild climates. The greater the temp diff
between outdoor and in, the less effieicnt it gets. So its inefficienct
in the coldest weather, not ideal. Still better than plug in leccy
heaters tho.

The other issue is the upfront cost. I gather this has fallen a lot now
tho.


I guess by the same token, the cooling process is reasonably energy
efficient also.

not compared to the other options, no.


NT