AC Not Keeping Up

I have one ac in my 37 ft trailer and 2 weeks ago temps in 100-105 I could maintain 80 in full sun except for the one day we took the dog out for a walk and came back and I thought the ac was in a cycle but it actually blew the breaker by the time I got it back on it was too late trailer got to 86 and could not get it down lower until evening. I only have single pane windows and I hung heavy each towels over all the window in the sun to help keep the heat out. It worked pretty good but it was very ugly visually.

dtappy3353 wrote:
do floor model/stand alone a/c's help if you only have 1 roof 13K unit?

Yes and no.

If it has only one exhaust hose, then it will "spot cool" the area that the cool blows on at the expense of the whole rest of the inside area.

This is because that hose exhausts a LOT of air.....which has to be replaced by air from somewhere. The replacement air is HOT air from outside, being sucked in through holes and cracks.

So to wrap it all up you need to get 2 more AC units, park in the shade, put solar shades on all the windows, park with the bedroom facing south, bring in all you slides and stand outside and hose down your rig. Simple!

first thing is the divider between the intake and exhaust properly sealed with foil tape?if not the ac is cycling to fast

dtappy3353 wrote:
do floor model/stand alone a/c's help if you only have 1 roof 13K unit?

Just asking.

You can buy a 'portable air conditioner' that has TWO air ducts, and it will bring in outside air, dump all the room heat into that air, and blow out really hot air through the other tube. It will effectively cool the RV and would be a good fix get you thought a miserable situation, but they will cost around $750.

Chances are that most local hardware stores will stock a single tube portable A/C. It takes inside air, heats it and dumps the heat into that 200 CFM air stream, and sends that air outside. Problem being that 200 CFM of humid and dusty air will infiltrate back in, warming the RV all the time, and you will not really ever get it cool.

Home Depot sells portable A/C units. You can sort 'single pipe' and 'Double pipe' - but most of what they stock in the local stores are single pipe, that cost around $100 less to buy them.

I would be looking for a cooler motel room, or going back home if it was 90F and I could not sleep!

Fred.

Hi,

Simple test. Check the air temp going into the A/C unit. Say it is 90F, then there should be 70F blowing out. If you are getting 90F in and 80F out, you are low on Freon, or have another problem that must be checked by a pro.

Cleaning the outside coil would have been my first recommendation, but you said that you have down that. IS the air blowing out on the roof really warm? I am guessing it is around 100F outside, so it should be heated by 15 - 20F warmer than the air going into the unit. If it is a lot warmer = say 100F in and 130+ out air on the roof top fan, you might have a clogged coil, clean it again with a garden hose. Yet my guess is that you have 100F in and 105 - 109F out, again indicating that the Freon level is way to low.

Finding a company to service them will be difficult, and could be really expensive, that is why many replace the $800 unit, rather than spend 5 or 6 hours of shop time working on it. The last HVAC company that I worked for charged around $120 - $150 per hour to work on commercial buildings!

You might check for local appliance repair places. Look for a small shop, perhaps advertising on Craigslist? If they can fix a refrigerator, they can also recharge a rooftop A/C. Both require a Freon fitting be installed to add Freon. It is just that home refrigerators use R-134 while the rooftop A/C on a newer unit is R-410, or ones installed before about 2010 would use R-22, like most home systems still in use today.

Good luck!

Fred.

do floor model/stand alone a/c's help if you only have 1 roof 13K unit?

Just asking.

During really humid conditions a delta-t of an RV AC unit can still be around 14 degrees and considered okay. Certainly short cycling could be an issue, but a probe thermometer measuring intake air and then cooled air, for 5-6 minutes at each location closest to the roof unit will yield the best diagnosis at this point. If less than that dig deeper for possible air leaks. If you get 14 degrees or more of temperature difference then the unit is operating as designed.

2001chevyturk wrote:
Our 2013 Sandpiper 365saq Dometic AC just can't seem to keep up on hot humid days.

What's the temperature of the air coming out of the vent(S) ?

If there is not at least a 20 degree drop from the intake, there is a problem with the A/C unit.
Then, how's the air flow....does it feel like the air is blasting out good like it should ??

Even in my little C, I find that I must run the A/C most of the day.
If you leave it off until mid-afternoon, it might be midnight before it's really comfortable again.

If the air is cold and the flow is good......it might be doing all that it can.

Just one AC on that 41' trailer? Definitely you need to add another if not two. We had two in our 38' Toy Hauler and two in our 35' motorhome. In high temps it gets it cool but not cold, but if temps are 95 I can easily maintain about 72-74. One thing you can do now to help is to bring in slides, that reduces the volume of air you need to cool and may help out some.