Looking for feedback/knowledge from folks...what should our expectations be about the Dash A/C in our motorhome? We have a Georgetown Class A that is on the Ford V10 chassis. It has a dash A/C, which blows cold air (if you put your hand right in front of the vents) but you don't really feel it being cold when it blows on you.I had our dealer check it out, and they said it's blowing fine...but that in a motorhome like ours the dash A/C really isn't supposed to be useful. You're supposed to rely on the big A/C units on the roof. Well, that means that we always have to have the generator running when driving.Is this true? Or should I be arguing with the dealer that the dash A/C just isn't right?

Our Ford V10 does not have great dash air either. Depending on the outside temps, we can usually drive comfortably, but it will not cool the entire coach. I usually leave a top vent open in the back, and/or run the fan to pull cooler air further back. If it is very hot, we do have to run the generator and overhead airs. Many folks hang an insulating curtain right behind the drivers seat the localize cooling to the front.

I expect it is fine. We use ours and aim the vents at us on hot days. On really hot days we fire the genset and cool with it in conjunction with the chassis air. There is just a lot of cubic feet of air in the driver's area for even a robust dash unit to cool

Bottom line is if you can get a 25-30º drop below ambient at the vent you're doing very well. If I remember right 20º is considered "acceptable" by most techs. I use a thermometer like THIS to check the temp' of the air coming out of the vents.On hot days I pre-cool the coach with the ACs before travel, and if running into the sun will fire up the generator and front AC to help the dash unit.

check the outlet temp and the inlet temp, down on the floor at the passenger feet. You should have good air flow out and be able to feel it. If not check the hose connectors. Also check to see if it is blowing up on the defroster. If so you have a gate that is not close. Post back on what you fine.

My dash air works great (workhorse). I just close the back bedroom door and run the AC on recirc. Of course I am only 27 feet long too. Only had to use the rooftop once, when I was stuck in stop and go traffic to give the engine a break. Didn't want an overheat.

Dash Air Conditioning | Good Sam Community

Johno02
Explorer
Jun 08, 2013
Our Ford V10 does not have great dash air either. Depending on the outside temps, we can usually drive comfortably, but it will not cool the entire coach. I usually leave a top vent open in the back, and/or run the fan to pull cooler air further back. If it is very hot, we do have to run the generator and overhead airs. Many folks hang an insulating curtain right behind the drivers seat the localize cooling to the front.
Horsedoc
Explorer II
Jun 08, 2013
I expect it is fine. We use ours and aim the vents at us on hot days. On really hot days we fire the genset and cool with it in conjunction with the chassis air. There is just a lot of cubic feet of air in the driver's area for even a robust dash unit to cool
daveshan
Explorer
Jun 08, 2013
Bottom line is if you can get a 25-30º drop below ambient at the vent you're doing very well. If I remember right 20º is considered "acceptable" by most techs. I use a thermometer like THIS to check the temp' of the air coming out of the vents.

On hot days I pre-cool the coach with the ACs before travel, and if running into the sun will fire up the generator and front AC to help the dash unit.
MountainAir05
Explorer II
Jun 08, 2013
check the outlet temp and the inlet temp, down on the floor at the passenger feet. You should have good air flow out and be able to feel it. If not check the hose connectors. Also check to see if it is blowing up on the defroster. If so you have a gate that is not close. Post back on what you fine.
weathershak
Explorer
Jun 08, 2013
My dash air works great (workhorse). I just close the back bedroom door and run the AC on recirc. Of course I am only 27 feet long too. Only had to use the rooftop once, when I was stuck in stop and go traffic to give the engine a break. Didn't want an overheat.
dougrainer
Nomad
Jun 08, 2013
ANY Motorhome dash air should get to at least 60 degree output at hiway speed at the outlet closest to the evaporator/blower housing. If you do not get 60, then there is something wrong. Most Motorhomes will get below 60 almost to 50 at hiway speeds. The operational guidelines by the AC makers sometimes state a higher temp but real world is at least 60 degrees. You MUST get a digital Thermometer temp to verify the actual temp. Doug
Cobra21
Explorer
Jun 08, 2013
Yes, 20 degree drop and will get cooler as cab does.
Mr_Mark1
Explorer
Jun 08, 2013
I might be mistaken but A/C is A/C whether it's in a class A diesel or gas unit, right? We can run the dash A/C up to about 95 degrees outside. After a prolong period of that temp, the rear starts to warm up from the engine heat.

Anything over that temp I'll crank up the genny and run all three air conditioners. It's nice to arrive at our destination with the interior cooled off on a hot day.

MM.
Fredzo
Explorer
Jun 08, 2013
I rarely use the dash air, since it seems like wherever I go is uphill both ways, and we live in the desert. You only consume about .6 gallons per hour with the Onan 5500 with both roof ac's running, and you're not using engine horsepower to run the dash air.
-Gramps-
Explorer
Jun 08, 2013
With front engine...20 degrees cooler than outside is a reasonable expectation. With Rear engine expect it to be a bit more. My AC will turn my knees blue but doesn't do much for the top half of me due to placement of the vents. Plus I don't have any mounted dash fans. They make a huge difference I think.

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