this post was submitted on 28 May 2024
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They're heat pumps in a technical sense, but coloquial terms, a "heat pump" is a heat pump which can actually heat a space.
The outside is a space too.
It's weird that there are any AC that can't function in heating mode at this point. In Australia at least, you'd be hard pressed to even find one that doesn't support heating.
I, for one, would support a law that requires any new unit over a certain size must be reversible and maybe even a tier where they must have variable speed compressors. But I can already hear the Republicans lying that the feds are coming to steal your window units.
Of course, even modern window units (and portable AC) support reverse cycle. But conservatives will find a way to complain about it, agreed.
This way it's $5 cheaper! Profit.
Here in Cali there are a ton of homes that have wood burning fireplaces in them so often that’s viewed as the “heater” if need be and the AC is for cooling.
AFAIK most American AC units can be retrofitted to be heat pumps pretty easily. You're just making it flow in reverse, after all.
In automotive at least, it's pretty common to size the evaporator and condenser coils based on their expected operating temperatures and (therefore) pressures. Usually this means condenser is a lot bigger than evaporator.
If you reverse the flow with the right valves and compressor setup, then the heat exchangers will still be sized wrong for efficiency. I suppose you could design a bidirectional system from the start that trades off for middling efficiency in both modes.
I'm not at all convinced that there are a substantial number of such bidirectional-sized residential systems installed in North America. But it's also possible that the residential folks don't care much about HX efficiency.
That makes sense, but also most heat pumps I know of are also AC units - like those mini splits installed in new apartments these days.
Would that not also be a balanced system?
And even if we're talking about lower efficiency it's still more efficient than burning gas in a furnace right?