If the Vapor aspect works well then this might make air source heat pumps tenable in cold countries. The current crop here in the UK are costing home owners a fortune as the 3-4 kw multiplier drops to 1 below 0degC or so and hearing becomes horrifically expensive. I know a chap who was paying £1,200 a month to hear is home at the worst of this winters cold and the energy price jumps we have here.
FYI, air-to-air heat pumps are very popular in Norway. There are models that have >2 COP in -15 C, for instance Toshiba Daiseikai 9S at 2.35 at -15C, and >5 at +7C.
"Cold climate" air source pumps have been available for years. Even my cheap MrCool Universal has 100% output down to -5F and it is not even really a "cold climate" heat pump.
