so technically, it's not generating electricity, it's moving heat from point A to point B, and believe it or not, 20f air still has a lot more heat energy in it than 0k air. So yeah, it's more than 100% efficient. Comparing it to electric resistive heating, which is producing the heat directly from electricity, rather than moving it around.

An electric resistive heater is 100% efficient, the efficiency of gas furnaces is measured similarly, though they hit about 90% eff, due to basic mechanics. Geothermal systems would also have greater than 100% efficiency as well, due to the fact that they just move fluid around, which is then cooled by the earth, (or warmed by it) though external heating wouldn't be.