[nqzero]

tangent: for a small air-to-air heat pump, what's the best commercially available coefficient of performance (COP) for a zero-delta-T ?

all the common ratings that i've found online refer to COP at a non-zero delta-t over a ranges of conditions. to illustrate my question, if you needed to pump heat from 70°F indoor air to 70°F outdoor air with a 1-ton unit, what would be the best COP you could achieve in 2022 ?