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Updated March 31, 2024
I don’t know about you, but I can’t stand being too hot. And sometimes on super hot days I just can’t get cool enough while driving our RV. So I was wondering if I could run the RV rooftop AC while I was driving to help keep me and the rest of the RV nice and cool.
Of course, I did some research, and I was very happy to learn that the answer is YES! It is perfectly fine to run the RV A/C while driving!
Now when we drive on hot days, I stay cool, and we keep a blanket in the front seat so Susan can stay warm.
When I told Susan I was researching for the article, she asked me a bunch of questions about it. Do you have to run the generator while driving to run the A/C? Do you need a propane generator to run the A/C? Is it safe to run the generator? Is it cost-effective?
Well, we will answer all of these questions and more in the article ahead. So keep reading to learn how to stay cool while running the rooftop A/C while driving on hot days.
Why Would I Want to Run the Rooftop A/C While Driving?
This seems like a good place to begin the article. There are several reasons why you might need some additional A/C to stay cool while you are driving. And the type of RV you drive may play a role, as well.
One reason you may want to run the A/C when you are driving is that it may be so hot outside that the dash air conditioning just isn’t strong enough to keep you cool. This happened to us while we were driving in Death Valley, California, but it could happen anywhere.
The reason this happens is that the dash air has to keep the driving cabin cool while overcoming the heat from the back of the RV too.
Another reason you may want to run the rooftop air conditioner is to have more engine power when you are driving through mountains on hot days. Running the dash air puts a strain on the engine when climbing uphill. In order to get more engine power, I will turn off the dash A/C and run the rooftop A/C so we can stay cool and maintain a decent speed on the uphill climbs in mountain areas.
And finally, you may have passengers on board and the dash A/C will not keep the back of the RV cool enough to keep them comfortable. So, this is a great time to run the rooftop A/C and keep everyone cool and happy.
Does the Type of RV Make a Difference?
Yes, the type of RV (Class A versus Class C) does make a difference. We have a Class C RV so we have a couple of advantages just because of the design of the RV.
First of all, the windshield is shielded from the sun by the over the cab bunk, which extends out over the windshield like a giant visor. Also, the Class C design allows us to put the cabin curtain up behind us while we drive. This creates a smaller area for the dash A/C to cool while we drive.
Class A RVs are a different story. The windshield is huge and unshielded from the sun so the cab can heat up quite a bit. Also, separating the cab from the rest of the RV in Class A is more difficult.
Therefore, the dash A/C has to cool the cabin and some of the warmer air from the back of the RV to keep the driver cool. Although Class A RVs usually have fans around the windshield that can help to keep the front cabin area cool, on very hot sunny days, the fans may not be enough.
Do I Have to Run the Generator to Run The Rooftop A/C?
Yes, you have to run the generator to run the rooftop air conditioner. You have two different air conditioning systems in your RV. One is the dash air, just like your car’s A/C. It is powered by your engine and blows warm or cool air through the vents.
The other air conditioning system in your RV is the rooftop air conditioner, which runs off of electricity. So, you can actually run your dash A/C and rooftop A/C at the same time. And in fact, many people do just that.
There are two sources of electricity for your rooftop A/C. One is shore power, which is where you would plug the RV power cord into the electric receptacle at a campground, for example.
The other source of electricity that can power your rooftop A/C is the generator onboard your RV. Whether your generator is powered by propane or gasoline it produces electricity, which in turn, powers your A/C unit.
Is It Safe To Run The Generator While Driving?
Yes, running the RV generator while driving your RV is perfectly safe. However, you should know a couple of things to ensure you don’t have any problems.
If the generator is gasoline-powered, you should be sure to fill up the gas tank before driving with the generator on. The generator uses the same gasoline from the same gas tank that the RV uses to fuel the engine.
You probably won’t run out of gas while driving, but the generator will automatically cut off if the fuel tank drops below 1/4 tank. This is a safety feature built into most generators to ensure that all of the fuel in the gas tank isn’t used up just powering the generator. The safety feature helps prevent a situation where you end up stranded in the middle of nowhere with no gas in the gas tank.
If your generator is fueled by propane, then you should be aware of state or local laws that may prohibit the use of propane while driving. For example, in Maryland, where we live, you can’t run a propane generator while going through the harbor tunnel.
Check out the video below for more info. RVTravel and The RV Doctor put together this quick informative video.
Is it fuel efficient enough to run the rooftop A/C while driving?
Sorry, but I wouldn’t say running the rooftop A/C while driving is fuel-efficient. A gas generator will burn about 1/2 gallon per hour, and I doubt your fuel mileage will increase enough to compensate for the generator’s fuel consumption. But, in mountain conditions, turning off the dash air while climbing hills could make the break-even point a little closer.
The main reason for running the A/C while driving is simply comfort. If you are on vacation or a full-time RVer, why forego the creature comforts of home like A/C and roast while you are driving. We put thousands and thousands of miles a year on our RV, and we certainly don’t want to be uncomfortable while driving.
Final Thoughts about Running the RV A/C While Driving
Driving with the generator and rooftop A/C on is perfectly safe and will help you stay cool and comfortable while driving your RV. Even though it is not the most fuel-efficient way to drive your RV, you and any passengers on board will be cooler and happier on very hot days.
I hope you found this article to be helpful for staying cool in hot weather while driving your RV.
Do you have an idea or suggestion to share about how to stay cool while driving in hot weather? Please leave your comments below!
If you would like to contact us directly, please feel free to visit our Contact Page and send us an email.
Learn More:
– How to Maximize Your RV A/C Performance
– WackO RV A/C Silencer: A Quieter Cooler RV A/C
– Can I Run The RV Generator While Driving?
– Will My RV Air Conditioner Run on 110 Electric Power
– Can Solar Panels Really Power an RV Air Conditioner?
To see a list of all of our articles check out the Blog Archive!
Mike Scarpignato – Bio
Mike Scarpignato created RVBlogger.com over five years ago in 2018 to share all we have learned about RV camping.
Mike is an avid outdoorsman with decades of experience tent camping and traveling in his 2008 Gulf Stream Conquest Class C RV and 2021 Thor Challenger Class A motorhome.
We attend RV Shows and visit RV dealerships all across the country to tour and review drivable motorhomes and towable trailers to provide the best evaluations of these RVs in our blog articles and YouTube videos.
We are 3/4-time RVers who created RVBlogger.com to provide helpful information about all kinds of RVs and related products, gear, camping memberships, tips, hacks and advice.
We tried doing this on a very hot day, but both ac’s blew warm air while we were driving running the generator. When we pulled over and restarted the ac’s, they were cooling while we were parked. When we started driving on the road, more warm air from ac. We asked several techs, but no one can tell us why. ACs run fine on shore power and while parked when using generator, but nnot while driving. 2013 Tiffin Allegro Red.
Great information! What happens if you are in an RV park in the summer but you don’t have any electric hookup and need to cool down your coach? If there is designated “quiet time” in the campsite what do you do?
Hi Salvatore,
I’ve been in this situation where I was boondocking and it was too hot. In that situation, I left and found a campground with electricity so I could turn on my AC. If I couldn’t do that and I couldn’t run my generator we use a large battery and a fan that we keep on board.
We can use the Schumacher Instant Power Station to plug things in, it all has USB ports to charge our phones and camera gear, and an air compressor, and an air pump to blow up air mattresses and it can jump start the battery that powers the RV engine. It does a lot and I highly recommend you keep one on board too. Here’s the link to find it on Amazon too https://amzn.to/3nfWCTW
It will power our fan overnight and then when we can turn the generator on after quiet hours we recharge it so we can use it again!
Your article was very informative, but (you knew that was coming). My 40′ Itasca Class A does not have a roof AC. It is in the “basement”. Actually under the bed in the right rear. Anything different in running a “roof air” vs running a “basement” AC?
Thank you so much for this invaluable information…we drove in suffocating heat yesterday and couldn’t keep our coach cool because we didn’t know we could run the rooftop AC!
In 100 degree weather, is there danger in overheating the generator while driving?
Not on a modern generator. I leave the Phx area every July heading for cooler climates. Often it is 115deg+ and I run the coach AC’s off my onan marque gold 5400 without difficulties. The generator has an Overtemp shutdown safety. I’ve never triggered it. Once when it was 118deg I couldn’t get the coach cooler than 80deg while driving. Better than the alternative. Having said this, I do run full synthetic oil in the generator because of its better heat handling qualities. It makes me feel better. Not sure it really matters. My generator has over 1,200 hours on it.
My class A is gas engine up front. One thing to consider. If you get into slow traffic. The engine puts out a lot of heat plus the road is hot. The generator is using this air to cool itself. It may overheat.
Hi Stan,
That is a really good point.
Thanks for sharing!
Mike
Thanks for the info! I plan on becoming a full time Rver in the future so I’m trying to gain as much knowledge as I can.
Hi Jennifer,
I’m glad you found the info helpful. If you have any questions please don’t hesitate to email me directly or leave your question in the comments section.
Thanks very much for letting me know you like the information!
Mike
I too enjoyed your blog. My husband said you could run generator and ac while driving, but I didn’t believe him .I do you.