Air conditioning

[Elycas10]

I have an Itaska 34B and was recently told that while under way, I should use the gen and coach AC as opposed to the chasis AC. I was told that my mileage will improve. Is this true?

KW

[Old Scout]

Probably not----curious, what fuel powers the genset???????? A bit less engine fuel, a bit more genset fuel--probably a wash....primary reason for running genset and roof air is to supplement dash air on really hot days---not to save fuel....

[smiller]

Your dash air uses a compressor powered directly by your engine and your coach air first has a generator turn mechanical energy into electrical power, then converts the electrical power back to mechanical energy by the compressor in the air conditioner so with the extra (lossy) conversion steps it's hard to believe that latter could be more efficient per BTU. As above, the reason you'd run your coach A/C is simply because you need more cooling than the dash system can provide, not because it's magically more efficient. Both methods burn diesel fuel and would likely be a wash at best.

[Davel]

I agree that it's pretty close to a wash in expense, My gas generator manual states that it uses .6 gal/hr vs. what the engine would use powering the dash unit. I resisted using the generator until we took a trip thru the Rockies in very hot weather. The dash air would not cool the coach very well and I didn't want to give up horsepower running it going over the mountains. I started using the generator/house air and very quickly came to enjoy the improved cooling. I doubt if it would make much difference in expense...and when you're talking about how much it costs to run one of these it seems like a drop in the bucket.

Good luck,
Dave

[NeilV]

You should do what makes the coach comfortable for everyone.

Sometimes the best choice is to run both with the house AC set warmer and the dash AC set to keep the driver comfortable.

I have an auto-start on my generator and just set it to start and only run when the house AC needs it. I live and travel in the South Eastern US where the roadway temps are regularly over 100 degrees and have a living room slide closed right behind the drivers seat so driving you are in a boxed off area surrounded by a lot of glass which can make for a dead spot that does not get enough cooling from the house AC at times so its all very fluid and varies by whats required to keep everyone comfortable.

[cochise1949]

Living and traveling throughout the southwest, in summer we tend to use both in midday. Roof air doesn't come close to reducing the gap between inside/outside when it is 100 plus out. The dash air isn't enough if the roof air isn't on. I agree that the driver gets the brunt of the heat when roof only is on. We do turn off dash air on the 16 mile grade to Vegas from Barstow though, I think the additional cooling in the F53 chassis would be up to the task.

[s1njin]

I use my generator all the time when I'm underway - mostly b/c I never use the generator any other time as we always camp w/ hookups. I need to put cycles on the generator, so why not do so while I'm underway?

I could care less about what saves more - I will tell you that if you can forgo the dash air it leaves more HP and torque for the engine since the engine isn't driving the AC compressor. So I'll take the performance gain, even if I don't see a MPG gain.

2 birds w/ one stone. Generator gets important cycles on it and I get all available engine power to drive the wheels.