Roof A/C

[Woolfy]

Need some input on the roof A/C while driving down the road. In the 80 to 90 degree heat range and using the roof A/C to keep your MH cool are the roof units large enough to handle it. The unit were thinking about has a 14,800 BTU rating and the MH length is 31'. We were looking at a Class A MH and were told that over 30' in length it's recommended to have two A/C to keep the MH cool. And how much more gas does the generator use while driving does it decrease your MPG a lot? Our knowledge in this is that you use the generator and the roof A/C to keep your MH cool and not the A/C on the engine motor as you will loose power driving

[Woolfy]

Need some input on the roof A/C while driving down the road. In the 80 to 90 degree heat range and using the roof A/C to keep your MH cool are the roof units large enough to handle it. The unit were thinking about has a 14,800 BTU rating and the MH length is 31'. We were looking at a Class A MH and were told that over 30' in length it's recommended to have two A/C to keep the MH cool. And how much more gas does the generator use while driving does it decrease your MPG a lot? Our knowledge in this is that you use the generator and the roof A/C to keep your MH cool and not the A/C on the engine motor as you will loose power driving

[smlranger]

Woolfy:

Welcome to the forum . You will find lot's of helpful folks and information here.

This is my opinion only but unless a class A is very small, I would suggest you look for one with two roof AC's. A lot of heat comes in via the large windshield of most class A rigs. We had a 32' 1997 Winnebago Adventurer before the current rig with two roof airs. We had no problem keeping the rig cool running the generator while underway.

Newer Winnebagos (above the most entry level rigs) have the basement air conditioners/heat pumps which seem to do a good job.

With our current rig, unless it is very hot (mid 90's and up), we keep the front of the rig very comfortable running the dash air. You are correct, that puts additional load on the engine but we've had no problems.

Whichever you choose, a fan or fans moving air in the rig will also help move the cool air around.

[Clay L]

The fuel used depends on the generator and the load.
Mine uses about .6 of a gallon per hour at full load as I recall.
Two ACs is not usually a full load for most generators and both ACs don't usually run all the time. Unless it's really hot they cycle on and off.
My best guess is that my generator normally uses about .3 to .4 gallons per hour while we are driving down the road with both ACs on.

Although power robbed from the engine by the dash AC is not really a problem for my motor home except maybe going over the Rockies. I run the roof ACs because it does a better job of keeping the motor home cool in both the front and back.
The dash air is really pretty good, but it has to struggle to keep the front really cool on really hot days.

["007"]

Woolfy welcome to the forum.
On my coach I have a 15,000 and 13,500 in bedroom area. The 15 will cool the front living area if I close a sliding door at mid coach and run AC on chassis from front dash area. I do not feel a lost of power with my chassis engine running AC. The mpg,s will be minor to you if your want to feel cool and comfortable while traveling.
Most of the coachs have the same combination of AC's in coach but you can option for larger ones and heatpumps from most MFG's you just pay the higher price.
Enjoy the forums and do ask the questions before you buy you have that right.

[Oemtech]

I had a 32' class C with a single 13.5k A/C unit installed. That unit was ok but worked hard in 100 degree heat. I had it replaced due to hail damage. I replaced it with a 15k A/C unit and it made a world of difference. SOOOO, when I got my 37' class A I opt'd for 2 15k units. They work in 100 degree heat. Bottom line, SIZE matters.

[Woolfy]

Thanks all your response to A/C question. I would just like to make a note here. Were looking at a Winne Class C Impulse 31C model and if we go ahead with it will get the larger A/C which is 14.800 BTU. It sounds like it might be border line for that unit to be comfortable in. I don't think Winne offers two roof A/C as an option. But one thing for certain will get the larger generator to handle the load.

[TXiceman]

I never heard of them offering more than 1 A/C on a class C.

Get the largest one you can get on it. Them you will need to cut the foil bubble insulation to fit the larger windows to help on hot sunny days, and also get a exterior windshield cover and line it with the same insulation. I added a felt backer to keep the aluminum from marring the paint.

Then park in shaded sites as much as possible and keep the windows shaded.

Ken

[tomsm]

Woolfy - Just a few general comments after owning several class "C"s and a couple of class "A"s. In general, it's easier to cool a C. You don't have that big windshield and the windshield you do have is partially shaded by the overhead "box". Also, when you set up camp and put up the privacy shade across the rear of the cockpit, you're only cooling about 25'-26' of a 31' coach.

You probably will want to use the dash air if it's really hot as it's hard to get a good flow of cooled air from the ceiling ducts down into the front seats of a C. I don't think you will even notice the loss of power.

I looked at the specs on the Impulse and noticed they don't offer dual pane windows. If you should decide to move up to the Spirit, I would highly recommend the dual panes. They help a lot with the heat load and also stop the sweating on the inside of the glass on cool nights.

Good luck with your choice - you're gonna love whatever you pick! Have fun!