Motorhome AC in desert

[Carolina_Moonsh]

We are thinking of going to Bullhead City for the summer in our motorhome. We know how hot it is there as we lived in the area for several years. We have a Newmar 1995 Mountain Aire with ducted AC. Can a motorhome AC handle that heat or will we need window units or portable AC's? Thank you!

[Cloud_Dancer]

Keep in mind that on these Newmars if the ceiling sags/droops where the ceiling air conditioner registers(small round and many of them) are mounted with/to the round "duct" that connects them to the linear ducts inside the ceiling, it will cause them to separate from these main ducts, and you will lose a whole lot of efficiency. The air conditioners will suck hot air inside the ceiling, and the cold output air will leak into inside the ceiling/roof cavity. IMO it's a design deficiency.

BTW any kind of small shade over the roof air conditioners will help noticeably. It did on mine, during Arizona summer.

[pnichols]

Also, even when you're not inside the RV during periods of exteme heat ... it's not good for the interior materials and appliances to be exposed to high heat hour after hour. High heat eventually destroys adhesives, plastics, dries out materials, etc., so the inside of the motorhome should be kept below 90 degress or so at all times, anyway.

Once while staying only a few hours in obscenely high heat in the Texas Panhandle during August in our motorhome, we found that running both it's ducted air conditioning and the cab's air conditioner (by idling the main engine) cooled down the entire coach in a real hurry. Motorhome cab air conditioners are usually much higher capacity than motorhome roof air conditioners.

I'm not a fan of swamp cooling for only cooling purposes. I believe it's main advantage is lower energy costs in the low humidity areas where it can be used. If you can afford it, I recommend increased air conditioning capacity .... which of course allows for greater camping flexibility in that if you ever want to stay comfortable in both high temperatures and high humidity conditions .... you can with adequate air conditioning capacity.

[Carolina_Moonsh]

Yes, I agree- thanks so much to all of you for your help!

[tpi]

If I was staying there for the summer I'd look into adding at least one more 15K BTU.

Also maybe check out campgrounds section and see if there are any campgrounds there with extensive shade or canopies you can park under. I can't stress enough how much difference that makes.

[Carolina_Moonsh]

only 1 AC- ducted

[tpi]

How many AC units are on the Mountainaire? It can really get hot there. I camped there one time in my trailer with high of 117, and I've seen it as high as 123F.
There will be a temperature rise in the interior in the afternoon.

It is not typically shady there, but if you can find a shady camping place you will be much better off. Nights can be in the '90s but the AC will work fine due to no sun loading.

For me an extended stay would depend on being in the shade, or not needing to occupy the RV in the afternoon, early evening hours. Perhaps with two or three good AC units in a class A, you would be better off than what I experienced in a trailer.

Swamp coolers are hit or miss effectiveness there due to frequent bursts of humid monsoon air. Quite a few homes in the area have both evaporative and AC installed-for any contingency. There can be periods of clouds and showers which help out the AC.

[time2roll]

Should still cool you off fine as the sun sets to get some sleep.
If you plan to hang out in the RV all day you might be disappointed.

[jrnymn7]

Actually, a humidifier with a block of ice in the water tray can serve as a very effective swamp cooler.

[2oldman]

Your Newmar might be ok. They're very well-insulated, more than most coaches.

Can't say I'd consider a swamp cooler. Adding moisture to the air doesn't make me feel comfortable.

[jrnymn7]

Dry heat? Use a swamp cooler. Humid heat? Use a/c.

I've been pondering the idea of a reflective fly, like you see on dome tents. That would block out some of the Sun's heat, while allowing air to pass between the fly and roof. Of course, it would not go well with flat mounted solar panels.

[Happytraveler]

We have an 35 ft. Itasca motorhome with ducted air. We stayed a lot in Palm Springs in April, May and June and the ducted air didn't keep up especially with the temps. reaching the 90's. So my husband temporally added a window air to cool off our motorhome. It helped tremendous.
Just recently we replace one of our fantastic fans with an Atwood air conditioner and tested it out last week in Canyon Lake, Az. We ran both air conditioners and it was nice and cold inside the motorhome.

[dahkota]

If you are parked in direct sun, it will be hot. To relieve some of the heat, try opening up the roof vents (heat rises). It will still only be 10-20 degrees cooler, but that is something.

When we were in Phoenix last year, it was 113 degrees. We had no shade but there was a breeze. It felt cooler outside under the awning with the breeze than it did in the rig. So we opened the windows on the breeze side and cranked up the A/C. Got the temps inside down to about 85 while the sun was still high overhead.

If you can find shade from the afternoon sun, do it.

[MEXICOWANDERER]

Forget air conditioning. It will prove near useless. Overwhelmed by magnitudes.

You need a swamp cooler. One measuring about three feet square. They are a SNAP to sell when you are finished with it.

The evaporative cooling from such a cooler is worth about TEN roof airs. And no this isn't a joke or exaggeration. The chilled air MUST have exits to outside. Both ends from the middle.

One 10-wheel Crown bus conversion. Two 13.5K roof air units on max. Outside temp 115F in Mojave desert. Inside temp 97F

Fitted one evapoative cooler. Same environment. Inside air temp 82 with AC turned off. I won't mention the utlility savings nor the 100+F in the bedroom heat.

This changes in late summer and early fall when monsoon season arrives. Higher humidity. Evaporative cooling becomes useless.

Yes, fitting a swamp cooler is not inexpensive and it's a bit of a hassle. But keep in mind Casinos with RV parking use swamp coolers for a reason.

Trying to keep a rig cool with AC in such brutal temps would be akin to fighting a brush fire with a water pistol.

From The School Of Hard Knocks

[rr2254545]

You will be hot