A/C question

[SpinnerBait_Nut]

My father-in-laws mobile home has a central air unit outside and a cooling grid in the furnace inside that cools the trailer.<br /><br />Now my questions is, why is it freezing up and stopping blowing cold air?<br />Is it low on freon maybe?<br />Dirty filter?

 

[ob]

Re: A/C question

Either the charge is low( due to a system leak ),the return air filter is dirty,or the fan blower is not working or its cupped blades are loaded with dirt and not letting it move enough air.The evaporator coils may also be packed with dust and causing an air flow restriction which will also cause it to ice over.

 

[SpinnerBait_Nut]

Re: A/C question

Thanks ob. I don't think the freon is a question cause after you let it thaw out, it will run you out if you let it.<br />We keep it set at 72* for him, or there abouts.<br />I will check the filters and stuff for dust.

 

[ob]

Re: A/C question

Bare in mind that once you confirm that the filter, evaporator,and blower are clear and clean and if this doesn't remedy the icing, that there is a fine point of undercharge that results in an icing evaporator.An excessively low charge won't do it.The drawback to running a system that tends to ice up (from slight undercharge)the evaporator at this point can result in refigerant oil being accumulated in the evaporator coils which can cause premature death of the compressor.Common leak sources are the suction and liquid line schrader valves on the outdoor condensing unit.Good luck and I hope its just a dirty filter.

 

[Ben Konopacky]

Re: A/C question

sbn; ob is on the money,just one more thing ,check dampers & registers,supply/return,make sure they are all open and not restricted (furnature,drapes)if it was a constant problem could be duct work..TOO SMALL..

 

[petryshyn]

Re: A/C question

SBN<br /><br />I don't know if you guys have such a thing down south but if the furnace has a humidifier built in, check to see if the bypass duct and the water supply is closed off for A/C useage...

 

[SS MAYFLOAT]

Re: A/C question

Spinner, occassionally I get this problem in some of our stores. Usually it is from overnight lows dropping down. This brings your head pressure down which in turns lowers you suction pressure. This will also cause your evaporator to frost over. Usually it is due to someone lowering the setting below 70.<br /><br />I would first check the temp of the stat by using another thermometer to verify that it is close to calibration. The stat could be saying it is set at 72 when actually it could be a lot lower.<br /><br />If your filters are clear, I would first try to raise the T-stat temp up at night to a higher setting to see if that takes care of the frosting.<br /><br />There are safties that can be added you your system to prevent frosting. One is a limit switch that just snaps onto your suction line. THe other is a low pressure control that will shut down the compressor if the suction line pressure drops down into the temperture where it causes your evap to frost over.<br /><br />OB is right about the death of the compressor if this is a continuing problem. The unit will pump all your lubrication into the evap. So it should be corrected before your compressor gets fried.<br /><br />Again overnight lows with a out of calibrated Thermostat can cause this as well. Just another thought for ya.... Good Luck.

 

[petryshyn]

Re: A/C question

SBN<br /><br />Be sure you are getting high fan speed when a/c is on. You should notice a difference between "heat fan speed" and "cool fan speed"...

 

[SpinnerBait_Nut]

Re: A/C question

Thanks all for the replies.<br />I checked all the filters and grills for any obstructions and it still doing it, so I called a professional to come tomorrow to look at it.

 

[SpinnerBait_Nut]

Re: A/C question

Well the repair guy came and found it to be less than a 1/2 pound low on freon, but said that was enough to cause this.<br /><br />Also informed me that the 2 compression fittings at the cooling coil were the culprits and that over time they will move just enough to cause a small leak like this.<br /><br />So all is cooling now like it should.<br />Again, thanks all.

 

[ob]

Re: A/C question

Glad you got her up and running and found your leak SBN.