Warm weather traveling

[wjschill]

After traveling in a 35 foot fiver for many years, we have now started looking at class A gassers. We like to travel out west and southern locations.

My question...Do you need to run the roof a/c's while driving to keep the rv cool? If so, doesn't this mean running the genny and killing an already challenged gas mileage?

May sound like a dumb question...

Thanks

[wjschill]

OP here.

Thanks for all the feedback. The DW was asking if she would be comfortable sleeping on the bed or sofa during our travels.

I figure, bouncing around while trying to sleep will be more of an issue than temperature.

Thanks again.

[mfinnerty]

When we had a 24ft class C with factory air. The dash air was able to keep the cab area cool. I attributed this to the smaller glass area of the windshield and cab over bunk shielding the windshield from the sun and reducing the area to be cooled. Now in our class A there is no way that the dash air can keep the cab area cool. I attribute this to the very large windshield. We always run the gen and usually only one of the two ACs. I learned long ago not to worry about MPG when driving our house down the highway. It is what it is.

[way2roll]

Since the generator is more efficient at producing power there have been strong arguments that the amount of fuel used by the generator to supply power to run the rooftop air is less than the drain on mpg from the engine having to run dash AC compressor. And I would like to see some statistics that the output of the dash air is greater capacity than two rooftop AC's. I struggle to find reasoning behind the logic of not using your onboard gen and Ac's, that's why they are there. If the dash air was more efficient why do you need a generator at all? Why not run the coach engine and the dash AC? The answer is simple - the dash AC is not better at cooling the coach, the rooftop air is. I know personally that when travelling in temps above 85, without the rooftop airs it would be downright miserable. No way the dash AC can cool the whole coach. Spend all that money on a MH with all the conveniences and not use them seems silly.

To the OP, this is simple. Yes you can run the genny and rooftop airs. Most folks do it all the time. The impact to MPG isn't worth the time trying to do the math. Do what makes you comfortable.

[DrewE]

The dash air is plenty powerful enough to keep the RV cool in nearly any conditions; it's generally equivalent to two or so roof air conditioners in capacity. The problems are getting sufficient and properly directed airflow through it to use the capacity and get the cooling where you want it. One thing that seems to help with my RV is to open the rearmost roof vent (with a vent cover, of course) a little while underway in order to promote cool air moving all the way through the RV--or, in cold weather, heated air.

It certainly is possible and sometimes reasonable to run the generator and roof air conditioner while underway, too. Occasionally on very bumpy roads some generators might stumble a bit, but generally it's no problem at all.

[way2roll]

On both our prior MH's we almost always ran the genny while underway. When travelling it's not just the sun above that increases heat, it's the engine, tranny and heat from the road. The only way to combat this is to run the rooftop air. And your passengers will thank you. The ability to use the central air, microwave, watch a movie on TV etc are all the reasons we had a MH in the first place. It's a rolling apartment and all the conveniences available at any time. Fully self sustainable with your own power plant. There is no more comfortable way to travel. Your MPG difference will be negligible, especially compared to your comfort. Frankly I never understood the curtain behind the front cabin to use the dash air and the heck with the rest of the MH. Doesn't that defeat a lot of the reasons of having a MH? And depending on where you go, it will take hours to cool the rest of the coach down when you get there. To each his own.

[H___E]

We always run ours in weather that is warm enough to warrant it. I also run the generator for the the heat pump in cold weather. That is one of nice features of a class A.

[craig7h]

With my three class a's I have always ran the gen.,I start the motor then start the gen. unplug and off I go.

The reason for me makes sense. The coach stays cool all the time, this way once stopped with no dash air the coach is already cool. I also like to keep the frig running on 120v with the gen. running my frig stays cold also. When stopping and want something warmed up to eat in the microwave its ready to go. Generators are made to run the little fuel they use to me is not worth it. But then I am not concerned about my fuel mileage. I have the coach to use if I get 5mpg or 50 mpg I am going to use the coach.

Enjoy

[Janss]

We've had two Class A gas motorhomes. Never ran the generator and house a/c. We've run around the western States every summer for the past many years. The dash a/c has kept us cool enough. Point the vents right at you.

When I have trouble is after we stop for the day. Very first thing I do is plug in to electric post and turn on the house a/c. Then I do the rest of the campsite setup outside, sweating, while the inside of the mh cools down.

[Tom_Barb]

wjschill wrote:

My question...Do you need to run the roof a/c's while driving to keep the rv cool? If so, doesn't this mean running the genny and killing an already challenged gas mileage?
Thanks

That's why diesel is better.

[Tom_Barb]

We have run the gen/set to get both A/C on full. The Newmar doesn't seem to mind.
of course it uses fuel..

[gbopp]

Hang a temporary curtain behind the driver/passenger seat.
The chassis A/C will keep you cool.

[rk911]

wjschill wrote:
After traveling in a 35 foot fiver for many years, we have now started looking at class A gassers. We like to travel out west and southern locations.

My question...Do you need to run the roof a/c's while driving to keep the rv cool? If so, doesn't this mean running the genny and killing an already challenged gas mileage?

May sound like a dumb question...

Thanks

not dumb at all.

- need? no, depends on how hot and when during the day you travel but it sure helps. we do.
- yes to running the genny. yes to affecting the MPG but it's minimal.

[rlw999]

My Onan 4000 is rated to use around half a gallon of fuel an hour at half load. My RV (28 ft class C) gets around 9.5mpg, so at 60mph running the generator would only lower my mileage by around 10%, which isn't a big strain on my travel budget.

As long as I get going in the morning when it's cool and don't stop for long, I haven't needed to run the RV A/C to keep it cool, the chassis RV keeps the front cool enough. But if I stop and park in the sun for an hour, then I need to run the big AC for a while to cool things down. For me, warm weather means up to around the mid-90's.

[Lwiddis]

Not a dumb question! Depending on the temperature you may need to run the ACs powered by the generator to maintain a comfortable temperature in the MH while driving.