Pumping refrigerant into evap?

[Larry2]

Years ago when I had to move the A-coil on my air conditioner, I pumped all the R22 into the condensor unit. I closed the high side valve, watched the gauges and when the suction dropped near zero, I switched the unit off and closed the service valves. I did this one occasion to move the A-coil. I did this again later when I decommissioned the system and brought the bits back for recycling. It seemed like most all of the refrigerent was captured with little lost.

What I want to know, is can I do a similar operation with a heat pump, where on heat cycle, I pump all the refrigerent into the indoor coil, so the outdoor unit doesn't have much refrigerant to recover. That would leave minimum refrigerent to be pumped off into the canister and make the compressor accessible for replacement.

[donato]

in cooling mode it will work. anyhow you said it has some servicevalves and your gauges so, just do it...

[Sir Josiah Sodd]

What I want to know, is can I do a similar operation with a heat pump, where on heat cycle, I pump all the refrigerent into the indoor coil, so the outdoor unit doesn't have much refrigerant to recover. That would leave minimum refrigerent to be pumped off into the canister and make the compressor accessible for replacement.




No.

I can't be done in the same way because the outdoor unit is the place where the refrigerant is stored when the system is pumped down (i.e. what you did before).

You can let the lot go (probably illegal) or do it properly and use a reclaim unit to remove the entire charge of refrigerant.

[Larry2]

I was thinking of putting it into heat mode, which exchanges the function of the evaporator and condensor coils. Then close the return line from the indoor coil and let the compressor run while it pumps hot refrigerant to the indoor coil,which is operating as a condensor coil for heat cycle. Then close the other valve and shut down the unit. I know the compressor is not happy pumping a vacuum because it needs return gas for cooling, but I think it may tolerate 30 seconds of that as it's last mission before replacement.

Next recover what remains in the outdoor unit through the service fitting on the condenser coils with the pump and storage bottle.

I wouldn't just vent the charge. The fine is $10,000 per event and its just not the right thing to do anyway.

[Brian_UK]

Larry, I assume that you have valves at the indoor coil to allow you to do you want.

You might find that the storage capacity of the indoor unit is less than the outdoor as the return line from the evaporator to the condensing unit should be full of liquid when in heat mode.

If you are planning repair works with all the pipework connected then perhaps you could run in heat mode with the 'suction' service valve at the outdoor unit closed until you have pumped the gas into the indoor coil and pipework.

[Larry2]

I don't have any valves at the indoor coil, but there are two valves at the outdoor unit. I assume they work like the service valves for the Carrier unit. I was thinking to close the suction side, let the compressor pump the indoor coil and then close the other valve. I think you're right though. The indoor coil is quite smaller than the condensor coil outide. It probably would hold only a portion of the charge. I think I have 10-11 pounds charge in this system. I guess it would be simper just to recover directly to cylinders.

[frank]

I guess it would be simper just to recover directly to cylinders.

And safer ;)

[Larry2]

And safer ;)

You know us yanks, always looking for the quicker way out. :D

[fruit656]

good thinking i see no problems with your method