Adding freon in cold weather

[murraybeck]

I need to add freon to my Cruisair unit to keep it from freezing up on heat cycle. Mechanic says the water temp is too cold (<60) to let it pull a vacuum. Is that right? Am I going to have to wait until spring for heat (at which time I won't need it)?

 

[bahamabreisus]

I am not an AC guy, but I would assume as long as the compressor is running it will pull the Freon. I'm sure one of the AC guys will chime in

 

[mainstream]

You can charge in cool weather you need to put system in cooling mode and you also may need to warm the refrigerant bottle you will not get accurate charge numbers but should be able to get fairly close are you sure the refrigerant is the problem on heat pumps there should be a defrost cycle but I'm not sure on marine heat pumps

 

[peterkvs]

Murray,

You might need a different mechanic. There is no reason you can't put Freon in the system because of the water temperature. You can always charge in cooling mode. There is never a vacuum on the input side of the compressor, just a lower pressure than the output side. What you need is to have the pressure on the low side of the compressor be less than the pressure in the Freon bottle. That way Freon will flow from the bottle to the unit. If the mechanic has a fairly full bottle of Freon and immerses it in a 5 gallon pail of hot water he will have plenty of pressure in the Freon bottle to get it into the unit.

However, are you sure that you have a Freon issue? if you have insufficient flow of the raw water through the cruiseair unit, you can't take the cold away fast enough from the heat exchanger and it freezes up. Check that you have a strong flow, check the strainer, check to pump impeller, check for kinks in the lines, and if your boat has spent much time in the salt water the heat exchanger might be fouled with marine growth.

Good luck,

Pete