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perryg114 · 10-04-2011, 07:19 PM

I was out working in the trailer today and it seems that if the sun is out the AC is pretty much worthless. The ceiling is always hot. The heat from the sun goes through that aluminum skin and what little insulation is in there. It was about 80 today here in Alabama and sunny. I think that with the AC on it was still about 80. THe AC seems to be working ok. I got a 20 degree differential between the intake and exhaust. I am assuming hot ceilings are normal? I do need to clean the roof which will help it reflect more heat.

Perry

overlander63 · 10-04-2011, 07:28 PM

Perry, you can paint the roof sheet with white Kool-Seal, and it will cut down a lot on the heat. I did this on ours, and was able to comfortably work on the roof in the sun (in shorts), but our friends' identical Airstream with silver roof left me feeling like I needed to roll myself in some breading. I installed air conditioners on both trailers the same day.

Splitrock · 10-04-2011, 07:43 PM

My air conditioner gets so cold in mine that I could hang meat in there.

Inland RV Center, In · 10-04-2011, 08:41 PM

Quote:

Originally Posted by perryg114

I was out working in the trailer today and it seems that if the sun is out the AC is pretty much worthless. The ceiling is always hot. The heat from the sun goes through that aluminum skin and what little insulation is in there. It was about 80 today here in Alabama and sunny. I think that with the AC on it was still about 80. THe AC seems to be working ok. I got a 20 degree differential between the intake and exhaust. I am assuming hot ceilings are normal? I do need to clean the roof which will help it reflect more heat.

Perry

Add a small fan, for better circulation.

That should help with the temperature.

Also, don't wait for the trailer to get hot before you run the AC.

Turn the AC on early in the day, giving it a chance to cool things down, BEFORE they get hot.

Andy

kidsgone · 10-04-2011, 09:46 PM

We have two Fantastic Fans that we turn on first prior to setting the a/c. We also turn on the fan at the a/c control and let all the hot air out. We have practiced this many many times with great success even in upper 90 degree weather. We let all of this run for about 15-20 minutes, then turn the a/c on. Cools down pretty fast after that.

idmtman · 10-05-2011, 09:01 AM

We discovered our AC unit had failed while returning home from Virginia via the southern tier. We were able to cool off the AS each evening enough to sleep comfortably by opening the windows, using the awning, and running the fantastic fan... at least until we got to Carlsbad, NM where it was 108 degrees. At that point we replaced the AC unit.

nautiqueman · 10-30-2011, 08:37 PM

I have had a '86 31footer and I now have a 2001 34' and both have very cold air. I suffer some heat at the beach when we are set up on sites without trees in Destin or Orange Beach, but the AC will freeze you at night.

Something is not right with your AC in my opinion. It is not hot enough here in Alabama in October for you to be uncomfortable in your AS with the AC on.

Inland RV Center, In · 10-30-2011, 10:13 PM

All RV AC systems can easilt and quickly be checked for proper cooling.

Run the AC for a few minutes and then measure the air temperature as it immediately exits the AC.

That temperature should be 18 to 20 degrees cooler than the ambient temperature inside the trailer.

If it's less than that, that would indicate a problem, such as low freon, or even a dirty coil.

Andy

perryg114 · 10-31-2011, 04:37 AM

I found a rats nest in mine and about half of the Evap coil was blocked with insulation. This helped a lot with increasing air volume. It was cold initially but now there is twice as much air. I get the 20 degree differential in temp from intake to outlet.

Perry

dznf0g · 10-31-2011, 06:49 AM

Quote:

Originally Posted by perryg114

I was out working in the trailer today and it seems that if the sun is out the AC is pretty much worthless. The ceiling is always hot. The heat from the sun goes through that aluminum skin and what little insulation is in there. It was about 80 today here in Alabama and sunny. I think that with the AC on it was still about 80. THe AC seems to be working ok. I got a 20 degree differential between the intake and exhaust. I am assuming hot ceilings are normal? I do need to clean the roof which will help it reflect more heat.

Perry

Something I found in mine...more sloppy workmanship. There was little effort to separate and sealing between the cold air outlet routing above the lower inside shroud and the warm intake air entering the bottom side of the shroud. In other words, I was recirculating a LOT of cold exiting air right back into the warm air intake before the cold air ever left the plenum. A little studying and duct tape and I had a significantly better performing A/C unit.

perryg114 · 10-31-2011, 06:58 AM

Yes I have noticed at least on the Coleman's that it is possible to recirculate a lot of the air. This can also cause the thermostat to turn the AC off prematurely because it thinks that the temperature is lower than it really is. I moved the sensor outside the unit to fix this problem. Mine was set as cold as it would get and it was still cycling on and off until I moved the sensor. Right now, I have the cover off because of another issue with the fan motor not wanting to start.

Perry

dznf0g · 10-31-2011, 07:07 AM

Perry, I get the moving the thermostat thing, but not ensuring a good seal between intake and outlet air still reduces cold air exiting VOLUME considerably.

perryg114 · 10-31-2011, 07:18 AM

Yes you are correct and I will deal with that issue when I put the cover back on. Right now that is not a problem with the cover off. I do need something on the intake to keep from clogging my Evap coil again. I need to get on the roof to replace the fan motor. Someone has already put some dents up there messing with the AC so I don't want to cause problems. When I replace the fan motor, I will blow the Condenser and Evap coils out with compressed air. I may be putting more work into this 30 yr old unit that it is worth but it still works. I already replaced the outside shroud on it. Every possible opening on this thing was full of mud dobber nests. These things can ruin lots of stuff.

Perry

Tim J · 02-04-2012, 04:41 PM

When we lived in ours for 2 years....we ran a soaker hose on the roof to cool the exterior surface. This allowed the A/C to catch up!

Inland RV Center, In · 02-06-2012, 08:14 AM

Running the AC, before the trailer gets hot, is the best way to keep it cool.

That gives the AC a "head start".

In that way, the AC doesn't have to fight an excess of hot cabinetry or interior metal.

Andy

c_lewis77 · 02-06-2012, 08:45 AM

During the summer here in South GA, I have found that if I have my A/C running in the early morning through the day is good. If I wait until mid day to turn it on it never catches up. At night it will freeze you out. I had an issue with condensation collecting in the covers of the exhaust fans that are inline with the A/C vents.
I can see why many people add the 2nd A/C on the larger trailers.

perryg114 · 02-06-2012, 11:53 AM

Well I don't have an AC anymore :-( . I am still debating replacing the unit or trying to find a fan motor that does not cost and arm and a leg. Time and mud dobbers have taken their tole on my unit. If I go new I will go with a 15,000 BTU unit. I am leaning towards a 15,000 BTU Dometic. Most places don't like shipping to a home address and I understand that because big trucks and sub divisions don't mix.

Perry

BIGED52 · 02-06-2012, 01:50 PM

Perry, Do you have a shop that could rebuild your electric motor? I have a place called Rock Island Electric Motor Repair about 10 miles from my home that rebuilt my Univolt. They are able to repair burnt windings and bad bushings etc. That might be cheaper and easier than finding replacement motor. Ed

perryg114 · 02-06-2012, 05:00 PM

Yeah, I have not had a chance to get up there and pull the motor. It is a bit of a pain to get at. Rats have been living in the thing on the inside. I would have to remove it to get all that junk out of there. I would rather replace it and maybe fix up the old one as a backup or sell it for $200 to someone who wants it. I figure the motor and cap are going to be $100+ and then almost another $100 for a new inside vent assy. I am already about $150 into it with a new shroud. It is getting to the point of diminishing returns. Outdoor Mart have given me a good quote on a new unit including the drain add on. I need to figure out how to ship it since they don't like shipping to home addresses.

Perry

TouringDan · 02-06-2012, 07:15 PM

Perryg114- My a/c cools my TW just fine, I guess because it is only 24 ft long. However I do wish that it was better insulated, so it did not run as much and did not have to drain off so much condensate.

idmtman- Now you are talking about my plan for keeping cool when I boondock at music festivals. I figure with 3 fantastic fans, LED interior lights, one or two small efficient 12v fans and four 6v golf cart batteries, I should be able to keep cool at night without the hassle and noise of running a 3 or 4 kw generator and my air conditioner. I have a 1 kw Honda genny that I will use during the day as needed to recharge the batteries. I alway try to point my trailer to the north also, so that the afternoon and evening sun does not shine on me directly but allows the Airstream and the awning to protect me from the heat of the evening sun. I have plans for solar too, but that will come later. I probably need to paint my AS lid white also.

Dan