A working engineer's tour of the heat pump as a thermodynamic machine: the vapor-compression cycle walked through honestly, Carnot as a ceiling and COP as a measured quantity, why cold-climate units do not collapse below freezing the way the 2010s ones did, the R-410A to R-454B refrigerant transition under the AIM Act, Manual J as the only honest sizing method, heat pump water heaters and dryers, and the homelab tie-in that almost nobody is brave enough to plumb.
Electrification
-
Heat Pumps: Carnot in Your Garage