Can I Run the RV A/C While Driving?

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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. So, 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 AC 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 AC? Do you need a propane generator to run the AC? 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 AC 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 AC 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 AC and run the rooftop AC 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 AC will not keep the back of the RV cool enough to keep them comfortable. So, this is a great time to run the rooftop AC 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 AC to cool while we drive.

Class A RVs are a different story. First of all, the windshield is huge and unshielded from the sun so the cab can heat up quite a bit. Also, it is more difficult to separate the cab from the rest of the RV in Class A. Therefore, the dash AC has 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 AC?

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, which is just like the AC in your car. 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 AC and rooftop AC at the same time. And in fact, many people do just that.

There are two sources of electricity for your rooftop AC. 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 AC is the generator onboard your RV. Whether your generator is powered by propane or gasoline it produces electricity, which in turn, powers your AC unit.

Is It Safe To Run The Generator While Driving?

Yes, it is perfectly safe to run the RV generator while driving your RV. However, there are a couple of things you should know to make sure you don’t have any problems.

If the generator is gasoline powered then 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 make sure all of the fuel in the gas tank isn’t used up just powering the generator. The safety feature helps to 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 which 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 at the end of the article for more info. This quick informative video was put together by RVTravel and The RV Doctor.

RELATED READING: We also have an article titled Can I Run The RV Generator While Driving for more info.

Is It Fuel Efficient to Run the Rooftop AC while Driving?

Sorry, but I wouldn’t say it’s fuel efficient to run the rooftop AC while driving. A gas generator will burn about 1/2 gallon per hour and I doubt your fuel mileage will increase enough to compensate for the fuel consumption of the generator. 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 AC while driving is simply comfort. If you are on vacation or a full-time RVer, why forego the creature comforts of home like AC, 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 doing all that driving.


Driving with the generator and rooftop AC on is perfectly safe and will help to make you 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!

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6 thoughts on “Can I Run the RV A/C While Driving?”

  1. 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!

  2. 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!

  3. 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

      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!


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