Wimpy AC units?

[Steve and Cindy]

It’s pretty hot here and our AC units can’t keep up. They seem to be blowing cool air but it’s still hot in the coach. AC has been on all day. This winter we’re going to Florida. I’m sure we’ll need the AC to keep up. Just wondering if any of you have ACs that don’t keep up or do we just have an issue with our rooftop ACs. They keep up just fine if it’s not that hot outside.
Also, is there any way to run both at the same time?
2000 London Aire.

 

[Neal]

I think most coaches, okay, well, mine, you have to stay ahead of the heat. Once you have heat it's hard to cool it back down. This means shades down, maybe insulation pads in the fantastic fan vents, magneshades to keep heat on the outside of the glass, the list goes on and I posted a thread here long ago about keeping cool tips. Cool down early and stay cool as again, once you're behind you won't catch up. With that, I've had good success.

Tip - Tips for staying cool in the summer in your RV

Tip 1: Stay ahead of the heat If you wait until you're hot to turn down the temps in your coach you'll never catch up. While it may be slightly uncomfortable on the cold side earlier, try to keep ahead of the heat indoors Tip 2: Balance your AC's I have a 40ft with 2 AC's. I typically keep...

rvforums.com

 

[Sealyn]

I run all 3 of mine at the same time, if you're on 50 amp running both is no problem.

 

[osuallen]

In addition to Neal's list, have you kept up with AC maintenance - cleaning the evaporator and condenser coils. Cleaning the filters. Also, if (big if) those units are original, they are probably getting old and tired.

 

[Kevin D Pem]

Back in the good old days, you know, when people knew what is a book? The answer to cooling was shade! I didn't say no ac just that shade reduces wall temperature thus the need for BTUs. The books gave the numbers, sure that is done digitally now! But I knew the book in my book shelf that had that information. Now it is just memory, so I lack the gains.

Are you using your awning?

 

[Sealyn]

To all responding, did you see where the OP is only running one AC unit at a time?

 

[Kevin D Pem]

To all responding, did you see where the OP is only running one AC unit at a time?

Of course we did! I only run one at a time, and the awning is out, and the solar panels shade a good part of the roof.

 

[Neal]

Also, is there any way to run both at the same time?
2000 London Aire.

If you're connected to 50A you should be able to run both. Does yours not allow this?

 

[AbdRahim]

I always run both AC's. I run the one where I am not sitting 2 degrees or so, lower so as to minimize blowing cold air on me as intensely. When I had a 30 ft class C with only one AC, it was difficult to cool the coach on a 95 degree day.

 

[Rich W.]

You can only expect a 20°-30° difference between outside and inside temp - for an older unit, probably closer to 20°. So the more you do to help (all the pointers previously offered), the better. Also as I think Neal pointed out, these units don’t recover well, so start early, get it cool before its hot, and then keep it that way.

 

[John&Andrea]

We just came back from three weeks in Navarre and Gulf Shores. It was a challenge to keep things cool inside. It was extremely hot. But we managed.

Shades down most of the day and extra shade on the windows as needed.
Cover and sky lights to keep heat out.
Cover any window that does not have a shade.
We covered the windshield inside and outside.
About 2 hours from arrival, we started the generator and ran the AC to cool things before arriving. This helped. When arriving the temp was around 100. We knew it would be a challenge to keep things cool.

Rich is correct, about 20 degree difference from outside is what we will see from these units.

 

[Neal]

About 2 hours from arrival, we started the generator and ran the AC to cool things before arriving. This helped. When arriving the temp was around 100. We knew it would be a challenge to keep things cool.

Absolutely great tip and something I do as well. Again, once the heat is in your coach you're behind. Use your GEN and A/C's even while driving in peak summer heat to help keep temps under control if your coach has this capability.

 

[Dan_Frisbie]

2017 34 ft Class A with one 15k a/c heat pump combo and one 12 k a/c. In Florida, in July, in partial (less than half) shade, the 15k alone kept the coach at 65 degrees with two adults and two dogs inside. We loaned it to my wife’s son and fiancé for the week.
It was a 30 amp campsite, so both units couldn’t run safely and reliably.

If your a/c is not keeping up with the heat, get it fixed. There’s no reason why a relatively modern unit can’t keep a coach cooled down.

 

[Rich W.]

A lot of good info here. For your coach, which appears to have one 15k btu and 1 13.5 k, I’d say the key take-aways here are to clean the units, run both at all times and start them early in the day, do everything you can to shield windows and skylights, park in the shade, and if that doesn't work, consider replacements if you still have the original 23 year old ACs. And if you do that get two 15k units.

 

[RKins]

I still have the original 13.5 k btu units on our rig. I follow all the advice already given and even if I'm only on 30amp site, I can run both AC - just nothing else

Another thing we figured out was that you need to have wind blowing on you to stay cool - we use a 12V "Endless Breeze" box fan, made by Fantastic Fan. Obsolete now though but it really works great. I tried to buy a new one but alI I found was on a scam site.

 

[BGMAC]

To help the AC I painted my roof with a white Acrylic Reflective roof coating like SunShield that they say blocks/reflects 95% of the solar heat. It helped a great deal and was glad I did.

 

[Bigblockyeti]

If you're not paying for water, you can get a $10 sprinkler and fix it temporarily to the roof to cool the top, some of the sides and the condenser.

 

[Kevind]

Watch out with a sprinkler. Make sure your ac seals are good, you don’t wast leaks. Replace your ac units!

 

[osuallen]

If you're not paying for water, you can get a $10 sprinkler and fix it temporarily to the roof to cool the top, some of the sides and the condenser.

Lots of hard water deposits, not to mention having things continuously wet is not a good thing.