to Virginia where the house is equipped with a “heat” pump. The poorest excuse for a heat source ever invented by man.
Since Heat Pumps have an
economical Temperature Difference Design,
Latitudes of the world make big difference in performance.
Virginia's Latitudes are at the upper edge for landlubber Heat Pumps, so they are still good, but not as good as Gulf Coast Latitudes.
Most heat pumps, even marine type, use
40-45°F as the
maximum difference between the heating source Air or Water AND the desire Home/Cabin for
economical sizing their heat exchangers.
Simple example for home:
Desired inside temperature 75°F
75° - 40° =
35°F
So a
heat pump will begin to struggle when the outside Air temperatures
drop below 40°F.
As they struggle, the desired 75° will begin to drop too.
But they still remove "
free heat" from the outside Air.
The
cost for supplemental heat by fuel or electricity is still much reduced.
Marine systems work much the same, using water temperature variations, but they are designed more for the Summer time cooling than Winter heating.
Since Water temperatures are LESS variant than Air, the Latitudes that work well are much further North than Virginia.
_____
It must be the new refrigerants.
The newest ones claim 10-35% efficiency improvements, but it from the Compressor designs innovations allowed.
Jim...
PS: How do I know this? I just replaced my
R-22 compressor [17 yr service].
R-417a was supposedly the newest replacement refrigerant. I talked directly with Tecumseh®, which is MOST marine refrigeration compressors makers. After full consideration of efficiency versus $$, I picked....
R-22.
Longer story and no thread
.