Fellow desert dwellers AC question

[prepilot_3ck]

All,

just picked up a 2016 Thor Outlaw 37RB. So far it's pretty slick. Been dig'n it on our first trip this weekend. We had a 2000 Class-A previously and sold it about a year ago. It was a really low-end, short DP, but we loved it. Anywho.. My question is regarding the AC.

This unit has dual 13.5K BTU AC units. One just behind the drivers/passenger seats, then one just aft of the kitchen. There is a window-style AC unit in the garage part that works pretty well, but we've kept that all closed off for the most part.

We're camping at Lake Mead in 105+ temps, no shade and it seems our AC units can't keep up. I'm not sure if they are not working 100% or if this is just simply too extreme for them. We're getting cold-ish air out of them, but set on full-blast (60 deg) we can't get the coach down below 80. It's just brutal in here. We have all the blackout shades pulled, the toyhauler is closed up, and all 3 ACs running on full blast. We're not cooking or doing much of anything inside. In fact we left for about 4 hours this morning, and came back and it was still 83-84 inside.

My question is, should a coach like this be able to get cool (into the 70's) under these conditions? I don't recall our old RV struggling this hard, but I might be mis-remembering.

What do yall think?

[theoldwizard1]

I have never camped in the desert BUT, ...

I am amazed that someone has not figured out some kind of sun shade that would cover major portions of the roof. Fabric or even screening to the wind can blow through. Get the A/C units in the shade make a BIG difference.

[the2sharps]

You can also add the bubble foil insulation on the outside wall in your cabinets. That should help some.

[ArchHoagland]

I had an external windshield cover made for my coach and use it in cases where the sun hits the front all day.

I think it's important to have an external shade as opposed to inside insulation. Block the sun before it gets in.

We also have a 20" box fan on the floor and circulate the air when it gets really hot.

In the evening I will open all the cabinet doors and let the hot air out. As you mentioned they get very warm.

[2oldman]

If you're in a park with everyone cranking the a/c, check your voltage. Just putting out your awning will help. I would have thought 2 airs would work better than that. I have one and yeah, when it's over 100 it starts getting uncomfortable inside.

Tinstar wrote:
If the air going into the return is 80 degrees, you should have, at least, 60-degree air coming out the A/C vents.

Mine blows 55 no matter what the input air.

[Chris_Bryant]

Depending on the layout, don't hesitate to install window awnings that are full available length , not just the Windows, but sidewall also.. Our old trailer had a full length window awning on the curbside, but only three windows, the rest was sidewall. Made a huge difference, but then I was in a 31' trailer with a single 11k but air.

[prepilot_3ck]

Everyone Thank you!

You've confirmed a few things for me.
I didn't buy a super crappy coach.

There is likely nothing wrong with my AC units, although a thorough inspection is probably a good idea.

and some great suggestions for dealing with the heat. Pulling the slides in (smart!) and working on some sort of sunshade for the front window beyond what's already there.

Thanks everyone, this is the information I was after. Outstanding.

Brian

[prepilot_3ck]

gsf35099 wrote:
The sun screen in the front window is a must. Our last big trip to Laughlin, NV back in last week of April it extremely unusually hot 103 to 107 for the first 5 days we were there. I jumped on the Harley & went to Home Depot & bought 15' of 46" bubble insulated aluminum stuff and blocked the window. It literally dropped the temp 10-15 degrees in the front & my AC units started turning off as the temp would get below 70 inside. I've got 2 15k's & have fought the heat for ~9 years like a goof ball. 😉

This entire summer in our area has been 100+ many days & I wish I would have done this years ago. Coach stays nice & comfy at 72 easily now even parked directly into the west sun with zero shade.

Good luck....

I love this suggestion. I'm going to start playing with this. I have 2 motorized shades in the front window. A sunshade, and a night shade. So no light is coming in, but that front area is like an oven. Next trip to The Depot, I'm getting a roll of the stuff.

Thanks,
Brian

[prepilot_3ck]

rgatijnet1 wrote:
Quite a few AC units are not sealed properly at the factory and some of the cool air leaks in to the roof frame instead of in to the AC duct. You may want to pull the bottom covers and make sure that all of the duct is sealed and that all of the cool air is going in to your ducts for the maximum amount of cooling.

I saw this on a Youtube video. Interesting.. I'll have my shop look at it when I take it in.

Brian

[prepilot_3ck]

2gypsies wrote:
Window awnings help greatly.

AH! we had those on our old RV. I must have underestimated their effectiveness because that was a much cooler coach (temperature).

Brian

[prepilot_3ck]

Chris Bryant wrote:
Just a note that the "20 degrees below outside" is 100% wrong. As Tinstar correctly stated, you get a 20 degree drop between return and supply air. If that rig is black, likely you need three 15k but units to keep cool in above 100 degree weather.

Bottom line is, reduce heat gain first, check ducting for air leaks, last add capacity.

Cool, that makes sense. It is mostly black, blue and white strips and whatnot but the primary color is black.

Brian

[prepilot_3ck]

Executive wrote:

gemsworld wrote:
Like others have said, expect the inside temp to be 20 to 25 degrees cooler than the outside temp.

This is true unless you your rig is prepped for the hot weather. I.E. Dual paned windows, black out shades, sun screens on the outside etc. We cranked up all three 15,000btu units in Yuma two months ago (117degrees) put the sun screens on and still had to drop the shades in the front to even get some semblance of coolness. In heat like that, you need to experiment with your particular coach to determine what you can do to make it comfortable. Parking under some shade will help as well. Get a roll of sunblock from Home Depot and make cutouts for the windows. Outside covers work best..How's the water level at Lake Mead? Where are you? AZ or Nev?.....Dennis

Yeah, this coach seemed better insulated than our old on, but apparently not enough. It's like eyeball frying hot out there. I love the idea of getting that bubble insulation for the windows. I might have to play with that a bit.

We are in NV. We love this park here in Boulder City and this is our go to park for a quick weekend get-a-way or a shake-down trip like we're doing this weekend. We're ready to get out and explore more though.

[prepilot_3ck]

Tinstar wrote:

azdryheat wrote:
Your a/c's seem to be working fine. Your a/c's only cool down about 20 degrees from the outside air temperature. Your RV has zip for insulation (it's only Styrofoam in the walls); you have about as much insulation as a Coleman cooler. I'll bet you don't have dual-pane windows, either. I've got 3 a/c's and the mid to low 80's is about all I get when it's triple digits outside.

That's not quite right. The A/C output should be about 20 degrees cooler than at the return air. The recirculating air has nothing to do with the outside air. If the air going into the return is 80 degrees, you should have, at least, 60-degree air coming out the A/C vents.

I've heard that about those piezoelectric coolers, and whatnot but not legit AC units. I'll have to have my shop double check the funk build-up in/on the AC unit and check pressure as well.

[prepilot_3ck]

ArchHoagland wrote:
Do your slideouts have covers?

Yep.

[prepilot_3ck]

doxiemom11 wrote:
Put pillows in the vents to keep heat out. Have a fan blowing, it helps you to feel cooler with the air moving. I think your A/C's are probably working just fine. Maybe less insulation and single pane windows contributing to less cool down. As someone said, putting the slides in does help.

Thanks. The slides seems like a common theme here. I might try that next time.

[prepilot_3ck]

time2roll wrote:
Could be normal. Certainly worth a look up inside. First check the plenum divider is well positioned and properly sealed between air in and air out of the unit. Some are done poorly and significant air just circulates in the unit instead of cooling the RV. Also check the ducting to the RV is well sealed to the unit. You don't want any extra cold air leaking into the ceiling cavity. Use aluminum A/C tape as needed.

After running a several hours non-stop look up inside to verify there is no ice on the evaporator. If they are getting iced up you will not be getting the proper air flow or BTU rating of cool air.

Assuming you have a wall thermostat you should have a freeze sensor that is placed against the evaporator to cycle the compressor if frost forms. These freeze sensors are often poorly placed or fall away from the evaporator allowing a freeze up.

If you are comfortable on the roof it is worth inspecting if the condenser needs to be cleaned.

If the park is full do check your voltage is above 108 in the RV in the afternoon. If voltage is sagging the compressor works extra hard.

Otherwise just let it run and keep a cold drink in hand.

I should get on the roof for sure. Not sure whats all up there. I need a ladder first. 🙂 This shake down trip has revealed some issues that our extended warranty could probably look at. I'll have the shop inspect the ACs....and I'll buy a ladder while I'm there.

Brian