4 ms·

There's no reason you couldn't just switch a couple valves out in your AC and perhaps change the refrigerant to make it into a serviceable heat pump. However, y

by elil17 3y ago

There's no reason you couldn't just switch a couple valves out in your AC and perhaps change the refrigerant to make it into a serviceable heat pump. However, you'd need to retrofit controls/electronics, which I don't think most HVAC technicians would know how to do. It's also not advisable to attempt to DIY something like this because it is very easy to accidentally vent the refrigerant, which is a very potent greenhouse gas.

__MatrixMan__ 3y ago
Right. It's a problem best confronted by the AC manufacturer. Except they have no incentive to do so (because if they don't, they get to sell an entirely separate heat pump down the line). Which means it's perhaps a problem for the regulator. There are tax breaks involved with installing "energy star" rated equipment. Perhaps we ought to start witholding the star from AC units that are not easy to convert to heat pumps (and from thermostats, etc, which are not ready to handle the conversion).
- elil17 3y ago
  I think that would be an excellent regulatory solution. You should write to your representatives. Since heat pumps are getting a lot of regulatory attention, it might actually get considered.
amluto 3y ago
By the time you do that, you might as well also put in a variable speed compressor and a variable speed fan, at which point there’s not much left. (Seriously, where I live, you will likely pay $1k or slightly more to drain and refill the refrigerant. The hardware for an entire modern heat pump, indoor and outdoor components, is maybe $3-4k. Is it really worth it to drain an old existing unit, cut the pipes, add a reversing valve, retrofit in the controls, pressure test everything, deal with the fact that the outdoor unit (formerly the condenser coil) will start producing copious amounts of condensate that the manufacturer and installer did not anticipate, and refill the system?)
- elil17 3y ago
  This is because HVAC companies wildly overcharge. It does not take $1,000 worth of labor to drain and refill refrigerant, but it does take a qualified technician, and there are not enough of those.
  - amluto 3y ago
    That’s absolutely true. But the same problem would exist, much worse, if everyone started modifying their old A/C systems to turn them into heat pumps. To add to the list of why this whole idea seems dubious: a conventional air conditioner operates with its evaporator coil at a balmy 50F or so. If you reverse it, the outdoor coil will become the evaporator, and it will operate below freezing if it’s cold out (even if the outdoor temperature is a bit above freezing). As a result, condensate can form and freeze on the coil. This is entirely manageable (any modern heat pump can operate in decently chilly conditions, and heat pumps equipped for low temperature operation can operate in very cold conditions), but I expect that at least some engineering is involved.

by elil17 3y ago

__MatrixMan__ 3y ago

Right. It's a problem best confronted by the AC manufacturer. Except they have no incentive to do so (because if they don't, they get to sell an entirely separate heat pump down the line). Which means it's perhaps a problem for the regulator. There are tax breaks involved with installing "energy star" rated equipment. Perhaps we ought to start witholding the star from AC units that are not easy to convert to heat pumps (and from thermostats, etc, which are not ready to handle the conversion).

elil17 3y ago
I think that would be an excellent regulatory solution. You should write to your representatives. Since heat pumps are getting a lot of regulatory attention, it might actually get considered.

amluto 3y ago

By the time you do that, you might as well also put in a variable speed compressor and a variable speed fan, at which point there’s not much left. (Seriously, where I live, you will likely pay $1k or slightly more to drain and refill the refrigerant. The hardware for an entire modern heat pump, indoor and outdoor components, is maybe $3-4k. Is it really worth it to drain an old existing unit, cut the pipes, add a reversing valve, retrofit in the controls, pressure test everything, deal with the fact that the outdoor unit (formerly the condenser coil) will start producing copious amounts of condensate that the manufacturer and installer did not anticipate, and refill the system?)

elil17 3y ago
This is because HVAC companies wildly overcharge. It does not take $1,000 worth of labor to drain and refill refrigerant, but it does take a qualified technician, and there are not enough of those.
- amluto 3y ago
  That’s absolutely true. But the same problem would exist, much worse, if everyone started modifying their old A/C systems to turn them into heat pumps. To add to the list of why this whole idea seems dubious: a conventional air conditioner operates with its evaporator coil at a balmy 50F or so. If you reverse it, the outdoor coil will become the evaporator, and it will operate below freezing if it’s cold out (even if the outdoor temperature is a bit above freezing). As a result, condensate can form and freeze on the coil. This is entirely manageable (any modern heat pump can operate in decently chilly conditions, and heat pumps equipped for low temperature operation can operate in very cold conditions), but I expect that at least some engineering is involved.