A/C Condenser

[whaler23]

My A/C condenser in the front cabin of my 36C will often start to ice up from the bottom towards the top if I run it continuously at 70 or below. Do I have a leak, is it low on freon, or do I not have enough fan speed across the condensing unit to prevent freeze up. It does blow cold about 56 degrees.

[Trojan]

Try changing the temp control raising it up some and increase the fan speed. It sounds as if you are trying to cool down to much and you are not passing enough warm air over the condenser. Make sure your condensate drain is not plugged and you not freezing the condenser because of backed up condensate. I had that problem once in my aft cabin. I don't think you have a problem with your unit.

BILL

[Fanfare]

Sounds like classic low freon.

[SKYCHENEY]

I've got one doing the same thing. I'm going to put the gauges on it next weekend and see what it looks like. I still have 6 cans of R22 that I bought before they pulled it from the retail stores. Hopefully a little shot of freon will do the trick.

[Trojan]

You can't freeze anything if you lack freon. Adding more freon could make things worse. Not better. If you can't dissipate the cold, the unit will freeze. If anything the unit could be over charged, but I would try the fan increase and the temperature increase first. Trying to cool a hot boat down to quick will also cause this.

BILL

[SKYCHENEY]

Yes, but the gauges will tell the story. Then we will know for sure what to do next and we won't have to guess.

I still think it's probably just a bit low on freon. I've seen this happen before but I will let you know the outcome after I get into it.

I'm no HVAC expert, but I imagine it starts to freeze up when the pressures are low because the liquid does not evaporate to a gas at the proper rate.

[67hat34c]

trojan, not sure what you are trying to say.

Fact is that freon when compressed gets hot, when it expands in the evaporator it gets very cold. If you are low on Freon, it has more room to expand and in fact gets colder. This is how a hight efficiency unit works. You build a larger evaporator and the freon will expand faster. You need to move more air through it or it will freeze up, need larger condensor to remove the extra heat.

There are a few reasons for a unit to form ice in the evaporator, low freon or low air flow throught the unit or both.

[67hat34c]

Whaler do you mean the condensor is icing or do you mean the evaporator is icing. evaporator is the unit that the air passes through, condensor is on the compressor unit in a split system unit.

[whaler23]

the unit that is mounted in front of the fan in my forward cabin, looks like a radiator.

[krush]

A low charge can definitely freeze up because the pressure drops on the low side and the temperature of the coils is directly caused by the pressure (look up some refrigerant tables). However, this is usually only the case for fixed orfice units. Low airflow and/or dirty coils can cause freezing too.

Check out this thread I posted on A/C stuff if you want some more info. http://www.samsmarine.com/forums/showthread.php?t=7126

You need to get some gauges and get some pressure readings, otherwise you are just shooting in the dark.