AC doesn't keep up with heat

[BobsYourUncle]

Not sure if I have an issue or not, but my AC can't get ahead of the heat.

We arrived in Fairmont Hot Springs RV Resort in BC this morning, set up and turned on the AC. It has been running non stop all day, and although it is reasonable in here, it is by no means really cool.

32' TT in sig, with a 12' X 3' slide. It is blowing cool, but not really cold. Unit is a Dometic 13.5.

Temperature outside is 34.3 C, or just under 94F.
Temperature inside is 24.8C or 76.6F. Not bad but I'd like it cooler.

I put my hand to a ceiling outlet and it's cool, but not that cold like I'd expect of AC.

We are pretty much open to the sun, obscured as it is by smoke from half the country being on fire.

Does this sound normal?

[dougrainer]

Desert Captain wrote:

Jack_Diane_Freedom wrote:
Well you have a 32 foot TT with a large slide. 13.5 Dometic will never do the job in that size of a trailer. I would think that even a 15k would have trouble keeping up. You are seriously under air conditioned in my opinion.

My thoughts exactly. A 13.5 BTU AC is only good for anything 25 - 27' tops. Secondly no RV AC, regardless of size is going to cool more than about 20 degrees {F} below the ambient temperature. Since the manufacturer skimped so severely on the AC I would be wondering what else they cheaped out on... just sayin.

:h

WRONG. the only 20 degree that is ever mentioned has to do with testing a functioning AC unit. HAS NOTHING TO DO WITH OUTSIDE AMBIENT. IF the RV has the correct AC unit/s it will get below 70 degrees in 90 and up temps. Doug

[jdc1]

BobsYourUncle wrote:
Thanks for the input everyone.
OK, guess it's normal then.
If I ever have to replace it, I'll put in a 15K unit.

Don't waste your money on a 15k unit. It's probably wired for a second unit. Same price, much better results. You may not even need another 13.5k unit. You can get a 9.5 unit, and be able to run it and the 13.5 you already have off the 30A you probably have.

[GMH]

Hi Bob. Thanks for your advice on my window issue. The airflow on your unit can be improved by pulling off the main grill and re-taping the duct inlets. Also a lot of units seem to have the divider between the warm and cold sides out of place which allows the system to short circuit. Check out this YT video and my thread here.

https://www.youtube.com/watch?v=a81Mq_hSzj0

https://www.keystoneforums.com/forums/showthread.php?t=48171

[valhalla360]

It's certainly possible to get more than 20 deg below ambient...just not with an underpowered system.

Another option to mitigate is to change out the vents with ones that can be closed and then open up the dump vents right on the unit. Then close off the bedroom and focus all the air into the living room area. Now you aren't cooling the bedroom/bathroom during the day. At night, without the sun beating down, you can open them and it should do better keeping up.

[wa8yxm]

The problem is not enough "R" in the walls and roof. So too much heat comes in. Also the color of the RV matters. My wife wanted a darker color so even upgrading from 13.5KBTU to 15KBTU it got hot.

Clean the condenser,, run fan setting on high, best I can offer.

[YC_1]

BobsYourUncle wrote:
Thanks for the input everyone.
OK, guess it's normal then.
If I ever have to replace it, I'll put in a 15K unit.

I went from 15K units to 13.5 on our 42 foot diesel pusher. We have dual pane windows and cover the front glass from the outside.

We cannot see any difference in the size of the units. We live in Central Florida where it is miserable in the Summer.

Shade is your friend and getting sideways to the sun if possible.

Close off the sleeping area during the day if possible.

One AC in that unit will not keep up so adding one might be possible.

[Grit_dog]

I’ll pile on and confirm the same.
Our 31’ single slide, in the sun mid - high 90s outside, AC would pull the temp down to about 80F inside.
Camper is basically new, AC works fine and once the sun goes down you could hang meat in it if you needed to.

[rhagfo]

If you don’t have an cover for your slide get one, it will help reduce the heat transfer through the roof.

[3_tons]

If it’s dropping temps by 20degF, better off to count your blessings…

3 tons

[down_home]

Check out and possibly clean the ac unit on the roof. If it still won't do the job higher output units are available. I don't know whether you are 30 amp or 50 amp. Competent Technicians, Mobile Tech generally better can advise on this. Some Towables 50 amp have provision, or did, such as our 2002 Holiday Rambler Fifth Wheel for two a/cs but came wit only one, wires everything and framing were there just covered by ceiling and roofing. Wee upgraded one heat pump that was acting up to, nearly double output,in Kingman, Az. Turned the RV into a meat locker. maintained 72 degrees in 103 to 113 degrees or thereabouts...and heat side kept it warm down to below freezing...but furnaces did kick in once or twice.

[ktmrfs]

BobsYourUncle wrote:
Thanks for the input everyone.
OK, guess it's normal then.
If I ever have to replace it, I'll put in a 15K unit.

A 15k unit will help but only marginally.

We have a 32ft with double slides and a single 13.5K Coleman.

If we are in the sun with the awning side facing east, it's brutal, inside drops about 15F sometimes less when temps hit over 100 and direct sun all day. And it hits 80 or so by late morning.

If we are in the sun with awning side facing west, as long as the awning is out even in 100F we can keep the inside in the mid to high 70's and it doesn't hit that till late afternoon. Awning keeps the afternoon sun off the side windows and trailer.

If the front of the trailer faces west, can keep the inside below 75 easily all day, AC will cycle on and off.

Front of the trailer facing east, trailer will stay below 75 but stay on all afternoon, Rear of the AC has a huge window.

And I have mesh window screens on the outside that help a great deal.

Trailers this size really need dual air.

Now, it's maybe a few days/year we have temps like this, some years non at all in the summer with max temps where we camp in the mid 80's in which case the AC does fine for us.

[BobsYourUncle]

Thanks for the input everyone.
OK, guess it's normal then.
If I ever have to replace it, I'll put in a 15K unit.

[wowens79]

I’m down here in the Southeast, so we deal with that regularly. My camper is a similar size, and only has a 13.5. Couple of things to try.
Get 2” thick seat cushion foam, and cut to fit in any skylights, or vents. Cut them just a little big and they will stay in place. Makes a big difference.
Keep the shades down during the day.
Set it on 65 at night and let it get cold all night, and that gets it a head start for the next day.

[Desert_Captain]

Jack_Diane_Freedom wrote:
Well you have a 32 foot TT with a large slide. 13.5 Dometic will never do the job in that size of a trailer. I would think that even a 15k would have trouble keeping up. You are seriously under air conditioned in my opinion.

My thoughts exactly. A 13.5 BTU AC is only good for anything 25 - 27' tops. Secondly no RV AC, regardless of size is going to cool more than about 20 degrees {F} below the ambient temperature. Since the manufacturer skimped so severely on the AC I would be wondering what else they cheaped out on... just sayin.

:h

[navigator2346]

Sounds like the AC is working fine. A 20 degree difference is about all that can be expected from a roof air