View/Navion & Staying Cool

Don't have any experience on this in an MB Class C but I guarantee that any Ford V-10 will keep the entire coach of a 24' Class C nice and cool eliminating any "need" to run the house air. I live in southern Arizona and we use our coach extensively year round in temps up to 115+ and have never had an issue with the dash AC getting the job done.

If it is going to be excessively hot we just open the rear Maxair hatch and run the fan on low. This draws the cold air from the front of the rig {the dash AC} and blows the hot air out. This would probably enhance the effectiveness of the Dash AC in a View/Navion. Our pooch {who has since passed over the Rainbow Bridge... sigh}, was always cool and comfortable lying on the rear queen as we traveled throughout the southwest.

IMHO: If you need to run the genny to power the roof air you should have bought a better coach.

As always... Opinions and YMMV.

:C

we have a liesure travel van, on a sprinter and have not had any problems cooling the rv going down the road, with just the chassis AC unit about the same size as a navion. drive back and forth from ohio to AZ.

Ours is 31' on a Ford, even then we can cool the coach back into the "living room" just not the rear bedroom with chassis (dash) air on the road.

But the question started out about Rooftop Air, run by Generator. That leads me to wonder "What about A/C while Camping?"

What's the BTU of the Rooftop A/C? Sprinters carry smaller "houses" than possible on Fords and Chevys, but I don't think I'd want anything smaller than 13500 on a Sprinter-sized Class C.

What kind of Generator? I'm sure it'll be size to run the A/C, but if so, with anything else. Our 4KW won't consistently run our 15000 A/C and let us microwave, but it's a large microwave.

And, what Fuel is the Generator? On Sprinter, Diesel is logical, but more expensive than Propane, so they're often Propane. Think of my questions coming back in a loop: If Camping is Off-Grid/Boondocking, in the Desert, AND Generator is Propane, your onboard Propane won't last as long as you might want to stay.

A few weeks ago we were camping in the Texas gulf coast, and daytime temperatures were close to 100 degrees. While traveling to the next campground, the in dash air kept the Via cool, but if we stopped for lunch, we had to put the generator on and run the roof air because the rv warmed up quite fast. At campgrounds the singe A/C kept it comfortable during the day and did get it down to low 70's after dark. We usually kept Reflectix in the front windshield while camping if the sun was hitting the front of the rv.

Regarding use of the cab A/C system - whether it be a Sprinter, Ford, Chevy based chassis - it's most effective if you don't expect the cab A/C system to keep cooling fresh incoming hot air from the outside.

Set the cab A/C system to it's recirculate mode so that the system is merely adding cooling to already-cooled interior air. Make sure to have all windows and vents closed to maximize this process. Don't worry about feeling weak from the interior oxygen getting low ... when going down the road there's plenty enough leaks even with all windows/vents closed to supply what our lungs require.

We travel this way in hot weather all the time and rarely has our Ford E450's cab A/C system had to be set to it's highest cooling setting or fan speed setting to keep the coach comfortable from the cab on back. The recirculate mode for our E450's cab A/C system is labeled as "Max A/C".

P.S. When traveling this way you also keep the coach interior nearly free of outside airborn dust/dirt, keep the interior air nearly free of other vehicles' exhaust fumes, and keep the interior air nearly free of slaughter yard/etc. smells. ;)

Just finished a trip with our 31' on an E-450 chassis Arkansas to California through New Mexico, Arizona, Needles, CA. Temperatures were near 110 in Needles. Dash Air worked great until Sun started coming in non-tinted windows. Fired up generator and ducted house air. Cab and living area stayed reasonably cool. Rear bedroom - a heat sink. Oscillating fan running trying to pump cool air into the bedroom helped.

When we got home, I purchased a Coleman Mach 8 9.2k BTU AC and added to the bedroom. A world of difference in cool down time. I prefer to sleep cool.

Smaller RVs probably do not need two AC units.

Rooftop a/c is only good normally for a 20 degree temp difference. Due to the outside factors of rv's. ( poor insulation etc...)

pnichols wrote:
Regarding use of the cab A/C system - whether it be a Sprinter, Ford, Chevy based chassis - it's most effective if you don't expect the cab A/C system to keep cooling fresh incoming hot air from the outside.

Set the cab A/C system to it's recirculate mode so that the system is merely adding cooling to already-cooled interior air. Make sure to have all windows and vents closed to maximize this process. Don't worry about feeling weak from the interior oxygen getting low ... when going down the road there's plenty enough leaks even with all windows/vents closed to supply what our lungs require.

We travel this way in hot weather all the time and rarely has our Ford E450's cab A/C system had to be set to it's highest cooling setting or fan speed setting to keep the coach comfortable from the cab on back. The recirculate mode for our E450's cab A/C system is labeled as "Max A/C".

P.S. When traveling this way you also keep the coach interior nearly free of outside airborn dust/dirt, keep the interior air nearly free of other vehicles' exhaust fumes, and keep the interior air nearly free of slaughter yard/etc. smells. ;)

I agree with you completely, why waste energy cooling outside air when you can more effectively use energy re-cooling the inside air that is already somewhat cool.

A Sprinter has one quirk that I am left wondering what MB was thinking when they did it....... The recirculate mode will only stay on for 15 minutes and then it will switch back to outside air. Every 15 minutes when you notice the A/C barely working again, you reach over and hit the recirculate button again.

On my Sprinter chassis one of the plastic cranks in the recirculate door linkage is broken, and irreplaceable, and I have permanently secured the door in the recirculate position. If I want outside air, I open a window.

Charles

pnichols wrote:
Regarding use of the cab A/C system - whether it be a Sprinter, Ford, Chevy based chassis - it's most effective if you don't expect the cab A/C system to keep cooling fresh incoming hot air from the outside.

Set the cab A/C system to it's recirculate mode so that the system is merely adding cooling to already-cooled interior air.

In numerous tests me and a bunch of others have proven this is not the most effective way to do it.

The fan in the dash A/C system is by FAR the weakest part of the system.

That’s why so many people incorrectly believe the rooftop unit is more powerful when in reality (in the case of a Ford C chassis) it’s barely a quarter the capacity of the Ford unit in the dash.

You need to move air, and LOTS of it.

Opening the rearmost roof vent completely and leaving the dash A/C on normal has been (informally) proven to be the most effective by far.

We live in the Arizona desert, and travel frequently in 100+/- degree temps. We like it cool and comfortable. We run both the chassis air and the generator/roof top air...every time. The generator usually needs some exercise anyway. And no...I don't care how much gas it uses.