Dash air vs generator
I'm sure this has been beat to death but, is it more efficient to run the dash air or to run the generator and one roof air.This is on a gas Ford v-10 and a 7000w Onan. Thanks for any input.
Forum Discussion
Mile High wrote:Effy wrote:SoCalDesertRider wrote:
The most economical way, is to run only one engine, not two.
Not necessarily true. While the engine does a good job of producing power to move the vehicle, it's not so good with the added load of driving the dash AC compressor. Thus why it's been argued that MPG suffers greater when using the engine to drive the dash AC to cool a portion of the coach rather than the paltry amount of fuel the gen requires to run the electric to power the ducted air and cool the entire coach. The generator is more efficient at producing the electrical power. So, in this case 2 engines being used at greater efficiency is better than one at a lesser efficiency.
1.2 gallons an hour for the generator isn't paltry. At 60 mph that brings fuel consumption down to 7.2 from 8.3. I don't think that AC compressor would impact mileage on my diesel anywhere close to that.
The efficiency difference is in how many btu's the dash air can push vs the full 40,000 btu's the generator can push through 3 ACs for that 1 mpg. When its hot and the passengers are miserable, none of the math matters.
What I said was" MPG suffers greater when using the engine to drive the dash AC to cool a portion of the coach rather than the paltry amount of fuel the gen requires to run the electric to power the ducted air and cool the entire coach"
so my comment was relative of the fuel usage of cooling the entire coach as opposed to the mileage suffering via dash air alone.
And yes to me the .5 MPG - my gen usage is nowhere near 1.2 - I doubt anyone else's is either - is paltry. All things considered when a rolling apartment gets 9mpg - who cares if it becomes 7 or 8? Heck a good headwind or hills will do that for you.
It's all a moot point for me as I don't measure MPG. I didn't buy my MH to monitor how much fuel I am using. I knew it used a lot before I bought it so 6.6 or 10, I don't really care. And so many factors affect MPG that it's such a moving target that gen usage becomes the least of my worries. I bought my MH to travel in comfort. I bought the unit I did so my budget wouldn't force me to watch mpg. It's smiles to the gallon for me.
