I think that the power required to strip heat from exiting air and insert it into incoming air is very modest, for a couple of reasons:
1. The quantity of air involved in bringing enough fresh air into a house to improve air quality is small.
2. The 'lift' that the machine is called on to do is also small. The machine will input warm air and output cold air, and the working temperature range falls easily within the R290 working range.
I think that 12K or 9K is just crazy large, unless you are talking about a substantial mansion or moderate+ manufacturing building.
It may have been mentioned before, but there are European units that admittedly operate in a modest-size, well insulated Euro house. I was not able to capture numbers, but the small compressor produced modest amounts of excess heat, which was stored in a DHW tank that was centrally located in the house.
I dug through my archives and wasn't able to ffind the reallly good one as listed above but I did find
THIS_ONE
It has some small pix of how they constructed it.
-AC