Advocates want new building codes to include a heat-pump provision that could benefit consumers and the climate. But regulators have cooled on the proposal.
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.
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.
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.
They’re heat pumps in a technical sense, but coloquial terms, a “heat pump” is a heat pump which can actually heat a space.
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.
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?