getting hot going down road with all ac on

[mmraceca]

it is a 2000 monaco diplomat, dash ac is cooling 20 to 25 degrees, which helps the driver and pass, but all the other people in the bus gets hot. I learned something going down the road the other day. I have been told to not run the dash air, so i tried it. I put a small fan on the floor pointing up at me driving. It is blowing very warm air, if i stand up and feel near the ceiling i feel very cool air from the duct work. We ran into some construction work and slowed to 10mph for 5 mins or so and i noticed the bus started cooling down. Then the traffic took off again, about 100 yards later the air from the fan on the floor blew very cold air for 30 sec and then the room was very warm again. Just for the record the motorhome gets nice and cold parked. Riding down the road, my wife said she thinks she feels heat from under the slide. Looking outside, the slide is tight up against the rubber seal and never leaks any water. Just interested in what all you think could be my problem, thanks in advance, Justin

[coachmanrvr]

Your (our) problem is capacity of the AC units vs the air "leaking or moving" through the coach at speed. Mine does the same. When still, your RV AC can cool the coach fine. When at speed, you have air actually moving all around the coach bringing in nice HOT air. Your AC system just can not keep up when moving. Don't know if the Prevost or MCI type rigs suffer the same, but anytime you use expanding foam to seal a coach it is not going to be air tight.

[Mvlawn]

We get a lot of heat in the back from the engine, if we dont close the bedroom door the ac units wont keep up. But with it closed they do fine.

[racer478r]

Had this same problem with my 2000 Diplomat. I cut a peice of sheet metal and attachecd it to the inlet for air to the coils on a/c. On this peice of sheet metal 2" by length of air inlet I cut several louvers bent out to force air in at speed. This helped my cooling.

[racer478r]

Had this same problem with my 2000 Diplomat. I cut a peice of sheet metal and attachec it to the inlet for air to the coils on air. On this peice of sheet metal 2" by length of air inlet I cut several louvers bent out to force air in at speed. This helped my cooling.

[mmraceca]

First time i have ever shut the bedroom door, but will have to say it was a big improvement. Just courious racer478r, are you talking about the recirculation vent by the steps? On max that is where the air is going back through the ac correct? Either way could you email me a pic or 2, cause i would like to improve anyway possible. mmraceca@yahoo.com Thanks, Justin

[Diplomat Don]

mmraceca......I've never heard of turning off the dash A/C when running the roof air. The dash A/C is still needed and the roof A/C just supplements the dash unit. On a 75-80 degree day, I'm sure you just run your dash A/C. When the temps go above that, you add the roof A/C.

I'm not a big fan of running the roof A/C when we drive, but were forced to on occassion. Its just the two of us when we travel, so I put a spring rod with a clear shower curtain up just behind the front seats. If we end up driving late into the day when its hot, we'll turn the roof A/C on.