Have you had this air conditioning mystery?

ladywendolyn · 07-19-2011, 02:31 PM

I woke up today and had my daughter turn on our rooftop air conditioner (non ducted) We are staying somewhere that it is very hot all day, but cools down at night. I got out of bed 20 minutes later, and noticed it was awfully quiet. It seemed that the compressor was working, but the fan was barely pushing any air out. Boy was I mad, a brand new unit, and now no fan. After calling around... No service available for a week... I pulled the grill off and looked inside. I noticed a bit of ice inside, so I turned it off to let it melt, and also put a little fan inside to help with it. One hour later... Ice is gone unit is working fine.....
But here is the question.... It was off all night...how could it be iced up so soon? Could this still be ice from yesterday? My daughter turned it on... If she accidentally turned it to the heat option... Would this cause icing? Anyone else had this experience? I am keeping the little fan running inside the unit, to help it not ice up... Anything else I can do?
Thanks

dimurrrw · 07-19-2011, 02:48 PM

No mystery. Phenom is called icing or freezing. Lots of info out there. Try searching for "rv air conditioning icing." Keep the fan on "run."

08flagvlite · 07-19-2011, 03:36 PM

This can be caused by dirty filters or dirty coils, also running the unit on "ON" instead of "AUTO" will cause this, because the compressor coils need time in the off mode to thaw out before coming back on to cool again. Which is also why running it on "LOW" isn't a good idea either. Not enough thawing out time. Our Coleman popup had some of these problems, which are also closely related to trying to cool a tent, basically. Also, humidity plays a role in the equasion, as well. We live in humid Florida. You cannot expect much more than a 20 degree drop in temperature inside the camper from the outside temp, so if it is 95 outside, 75 will be about it inside. Randy

The_Stuff · 07-20-2011, 06:25 PM

you sure the AC's fan is going? if it stopped it would ice up.

jimh · 07-21-2011, 08:44 AM

i wouldn't think switching from heat to cool would cause that. although, there are a different set of problems that occur with the switch valve inside a heat pump. (that's all i've ever been told...they didn't go into detail).
the air flow would be from the ice. u could have shut it down and waited abt 5 minutes and switched to heat for a couple (2) minutes and it would have thawed it out.
if it gets the trailer down to temp and then does it i would have it looked at. it could be humidity.

when i bought my trailer, on the walk thru, they told me that if i opened the quick cool vent on the a/c for a long time, it would ice up. (mine is ducted). quick cool would make it work more like a non ducted unit.

trudinator · 07-21-2011, 09:20 AM

Quote:

Originally Posted by 08flagvlite

This can be caused by dirty filters or dirty coils, also running the unit on "ON" instead of "AUTO" will cause this, because the compressor coils need time in the off mode to thaw out before coming back on to cool again. Which is also why running it on "LOW" isn't a good idea either. Not enough thawing out time. Our Coleman popup had some of these problems, which are also closely related to trying to cool a tent, basically. Also, humidity plays a role in the equasion, as well. We live in humid Florida. You cannot expect much more than a 20 degree drop in temperature inside the camper from the outside temp, so if it is 95 outside, 75 will be about it inside. Randy

Our house A/C isn't working properly, so we slept in our Rockwood TT for the last 2 nights. It was 99 yesterday during the day, and only "cooled" down to 88 by the time we went to bed. Humidity has been so thick you could cut it with a knife!! I'll be SO glad when this "heat dome" moves on. We're in Wisconsin, and I'm not used to this many days in a row with staggering heat and humidity. Our 13,000 BTU A/C has had no issues keeping up, although we're running it only at night. I'm pretty sure our AC is much more than a 20 degree drop in temp from inside to outside.

Kpinto · 07-21-2011, 09:29 AM

On your A/C that is freezing up. If the thermostat wire, cooper wire with a bigger end on it has came loose and dropped down off of the condenser it will cause it to freeze up because it will constanly run. Something is making the compressor run all the time and there has been a few reasons why listed. The only other thing would be if the unit is low on freon, probably not likely but possible.

Bill_C · 07-21-2011, 09:50 AM

Quote:

Originally Posted by trudinator

Our house A/C isn't working properly, so we slept in our Rockwood TT for the last 2 nights. It was 99 yesterday during the day, and only "cooled" down to 88 by the time we went to bed.

I wish it would get warm enough here in BC to turn off the HEAT !!

The_Stuff · 07-21-2011, 10:55 AM

the heat wave lifted here last night about 9pm! AC cut out and gf and i were like 'whats wrong with the ac' then we noticed it was down to 21 in the TT!

(70f)

trudinator · 07-21-2011, 12:58 PM

Quote:

Originally Posted by The_Stuff

the heat wave lifted here last night about 9pm! AC cut out and gf and i were like 'whats wrong with the ac' then we noticed it was down to 21 in the TT!

(70f)

Please, please PLEASE send that our way!! We have to wait until Sunday night before nighttime temps are back down in the 60's. Can't WAIT. Please remind me I'm saying this in January/February if I start complaining about the bitter cold.

dezolen · 07-21-2011, 04:52 PM

This can happen on home AC as well. Not a big deal unless it keeps happening. Keep fan running as this can happen with insufficient air flow. Also do not run fantastic fan with air on as it will only draw more humid air into trailer and Ac will not be able to keep up with excess humidity.

ng2951 · 07-24-2011, 06:43 PM

Pretty simple, lots of humidity and a a/c the coils froze up. Since the coils have iced air flow goes to zero and the system becomes a block of ice.

Just turn the compressor off and let the fan run. After an hour or so you will start to notice flow again. Let it run for a while after that before turning the compressor on.

Jf you want to confirm that you will probably notice that condensate water from the a/c is no longer dripping off the roof...

ladywendolyn · 07-26-2011, 12:46 AM

Thank you for all the info.... It seems most likely I caused this by running the unit on low. Too much compressor and not enough fan for the amount of heat and humidity. I will make sure I make a few changes.

rockwood06 · 07-26-2011, 05:16 AM

Major cause of A/C freeze up.

1. Low on charge due to a leak on the system. Your unit can not be recharged as it is, because there are no service ports, but that can be modified.

2. Lack of air flow, dirty filter, dirty eveporator coil, dirty blower wheel, blower motor not operating properly, loose blower wheel on motor shaft (blower wheel not spinning at the same RPM's as the motor, operating the unit in A/C Mode below 50 degrees with out a head pressure controller or a heat load with in the space that you are trying to cool.

If your unit has none of the problems above then there should not be any problem operating the fan on the "ON" position, high or low speed.

As far as humidity, the higher the humidity the more condensate you will produce from your unit this should not cause a freese up unless you have one or more of the problems above.

Here in the North/East our temps have been well over 90 degrees for some time now and we are living in our RV until our house is built, the A/C is on all of the time and i keep the fan mode on "ON" and on low speed all of the time to help with hot spots in the camper, the air is always moving and have not had any problems.

When a unit is low on charge there is not enough refrigerant in the system to obsorb the heat from the return air, this is when the unit will freeze up and if the unit is over charged then there is too much refrigerant, the unit will not cool but it will not freeze up as well and this can damage the compressor.

You may want to have your unit checked just incase.

Covfam · 07-26-2011, 05:54 AM

Quote:

Originally Posted by trudinator

Our house A/C isn't working properly, so we slept in our Rockwood TT for the last 2 nights. It was 99 yesterday during the day, and only "cooled" down to 88 by the time we went to bed. Humidity has been so thick you could cut it with a knife!! I'll be SO glad when this "heat dome" moves on. We're in Wisconsin, and I'm not used to this many days in a row with staggering heat and humidity. Our 13,000 BTU A/C has had no issues keeping up, although we're running it only at night. I'm pretty sure our AC is much more than a 20 degree drop in temp from inside to outside.

me too this humidity is painfull here in wisconsin.. we had heat indexes between 107-118 for a week and half .. i didnt get much done and hid in the house.

trudinator · 08-08-2011, 06:48 PM

Quote:

Originally Posted by Covfam

me too this humidity is painfull here in wisconsin.. we had heat indexes between 107-118 for a week and half .. i didnt get much done and hid in the house.

Where are you in Wisconsin, and where are your favorite camping spots?

Covfam · 08-08-2011, 09:05 PM

our farm is in jackson county about 8 miles out of black river falls. to be honest we havent camped IN wisconsin yet we have only lived here 5 years and most all our camping has been in south dakota, colorado and texas so far. most all our trips in wisconsin have been just overnighters at the holaday inn express

we are actually planning to go camping up in door county this fall and enjoy the fall colors there

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