Community Forums

KanzKran · 07-31-2019, 09:19 AM

I'm getting really close to pulling the trigger on a Class B, and after looking at a Chinook, I'm getting concerned that the dash A/C system alone isn't enough cooling while driving in hot climates. It was blazing sun and hot for my area (mid-90's), and the unit wasn't getting cool at all, even though the air was quite chilly coming out of the dash vents.

Sales guy clicks on the 50,000 BTU/hr 12VDC Pro Air unit in the back, and after a while it started getting better in there.

It also had the customary 120V 13,500 BTU/hr roof unit, but I don't know if that can run off the inverter while driving. I don't want to run a propane generator just to run the A/C.

So for those with Winnebago, Coachmen, etc. Class B units with only the dash air, how well does it keep up on a hot, sunny day while driving? We're buying this unit primarily for driving long distances in the southern US, including during the summer, rather than parking and living in it while plugged in to shore power. I don't want to make a big mistake in thinking the dash air will be adequate if it isn't, especially in the back on the couch, and I'm then stuck with my choice. Midwest offers the Proair system, as does Chinook, but they're pricey, but if it's really a necessity, that's what it's got to be.

A search here turned up very little, other than a mention of the Proair system in a Coachmen thread on their generator-free version.

**pasdad1** · 07-31-2019, 09:32 AM

Quote:

Originally Posted by KanzKran

Sales guy clicks on the 50,000 BTU/hr 12VDC Pro Air unit in the back, and after a while it started getting better in there.

Is that a typo? 50,000 BTU ? Even my sticks and bricks doesn’t have that kind of cooling capacity on 220 VAC

Winterbagoal · 07-31-2019, 09:38 AM

Our dash air cools the cab area, which is what it's supposed to do. The area to the rear, aka the coach, isn't really intended to be cooled by the dash air, but if you close the windows/vents and drive long enough it might.

A motorhome, of any size has different zones that can/will often be cooled by auxiliary rooftop units because of the distance from the cab area. The farther from the cab/dash zone you sit, the lower the cooling effect of the dash air, if that's all you're using to cool your motorhome.

KanzKran · 07-31-2019, 10:19 AM

Quote:

Originally Posted by pasdad1

Is that a typo? 50,000 BTU ? Even my sticks and bricks doesn’t have that kind of cooling capacity on 220 VAC

Yes, that is a typo. It should read "60,000 BTU". 5 tons of A/C, which is why I had "5" on the brain. 1-1/2 tons more than my single zone home A/C.

Check out the options at the bottom of the Midwest product page, under the Available Options tab.

https://midwestautomotivedesigns.com...nder-camper-rv

I've guessing that when they say it's 12VDC air conditioning, they're referring to the blower. The compressor is almost certainly engine-driven.

Jyrocharlie · 07-31-2019, 11:31 AM

Did the van skid to a stop when he clicked on that 50,000 btu 12v ac unit. (13,500 BTU Roof Top AC (shore-line / Gen) from that site.

Jlo11111 · 07-31-2019, 01:58 PM

I have a class B. The dash air cools the cab just fine on hot days, but the very back of the van will be a bit warm. Since I'm not back there when driving, who cares. If you do have people riding in the back, just start the generator and turn on the roof AC. Literally, don't sweat it. And if your van has enough battery/inverter/alternator horsepower, as some of the newest one do, just turn the roof AC on when your driving. I will note that when parked, my 13.5K BTU roof AC will only keep the van luke cool on very hot days.

goreds2 · 08-04-2019, 06:05 AM

Is there a way to hang a curtain just behind your drivers seat to keep tje cool dash air on your side?

hoosiermark · 08-07-2019, 12:49 PM

In the 70s when I had a hippy van I used a shower rod and curtain to block off the cab from the rear of the van. It was easy to slide open and closed and not permanent.

KanzKran · 08-10-2019, 03:51 PM

I’ve been looking at Coachman Galleria’s and just noticed some new ones with the optional Pro Air system at 20,000 BTU. I’m assuming it’s in addition to the MB dash air, but I’m trying to find out for sure. Two compressors or one? A complete second system of almost 2 tons of cooling would be great for me since the intention is to spend most of our time inside it traveling rather than plugged in somewhere.

magicbus · 08-11-2019, 02:53 PM

Quote:

Originally Posted by hoosiermark

In the 70s when I had a hippy van I used a shower rod and curtain to block off the cab from the rear of the van. It was easy to slide open and closed and not permanent.

Me too in my Dodge Tradesmen!

KanzKran · 08-21-2019, 09:50 AM

Is it feasible to upsize an inverter to power the roof A/C while travelling? Most of the units I'm looking at have either a 1kW or 2kW inverter, but they don't run the roof air conditioner. A very few units have the ProAir 20,000 BTU system, which I believe has an engine driven compressor, but none of the new ones I've found have the right exterior color and interior styling for DW.

So I started thinking maybe I could just run the roof air using a larger inverter instead of the generator, which is LP and won't run for long on the small tanks the Coachmen Gallerias come with.

But I don't know if the engine alternator can keep up, or will burn out prematurely even if it can, or could be upsized in order to keep up. The OE alternators listed in parts pages go from 120A to 220A, and the 220A would be running about half-output continuously just for the A/C, which may not be acceptable.

Or a second one added, but by that time, I'd have too much money into it and should look at other ways to increase A/C. Or spend the extra up front and buy the generator-less Galleria, but that's not really worth the giant cost adder to me just for A/C in the back, and I think I'd rather have the generator anyway.

Diesel-Lover · 08-21-2019, 11:59 AM

Remember the amps that the engine based alternator maxes out at and yes that is 12V. If you convert the amount of electricity needed for that roof air then add the residual necessary to run the vehicle you will be able to judge if you really want to do it. Besides MB alternator is probably not too cheap and a breakdown along the roadside is well a sweaty headache waiting to happen, unless you replace the alternator say every year of 20 k miles or some such crazy preventive maintenance, it would be best to source your AC running off a generator, if you like convert to a diesel generator or a gas fired one.

RossWilliams · 08-21-2019, 01:59 PM

We haven't run in really hot +100 heat, but the dash AC by itself seemed to keep the back pretty cool in our Sprinter based Roadtrek. Remember, the space being cooled has been shrunk considerably by cabinetry etc. In theory, the separate under-hood generator and inverter will both handle the AC if we needed it, but we never have.

KanzKran · 08-22-2019, 08:22 AM

Yeah, maybe I'm putting too much weight on the need for a second A/C system like the ProAir. If the dash A/C can mostly keep up, I suppose I could run the 2.5kW generator and use the roof air for those times when it's needed. The small 41 lb propane tank is only good for about 20 hours or so at 75% load, but if it's not needed all the time, I may be able to stretch that out over 30 hours travel time (with breaks) between Lake Ontario and Houston TX (for instance). That's assuming 41 lb usable, which would be a 12 gallon tank (100 lb WC), but the literature doesn't make that clear.

It would be nice if the Coachmen came with a larger tank, but they have the smallest of all the brands I've considered except maybe the Winnebago with the Murphy bed slide, which we aren't considering. I'd even install a larger tank, but I rather doubt there's room for that or Coachmen would have used a larger one, since the cost difference it usually pretty small for a significant increase in volume.