All of Your Questions About RV Air Conditioners Answered

Contributor

Tucker Ballister

Favorite Trip

5 Months Solo on the Road

Home Base

Hendersonville, NC

Favorite RV

2008 Fleetwood Bounder

About Contributor

Tucker Ballister is our Technical Content Writer. He’s a lover of the open road and the proud owner of a 2021 Sunlite Classic travel trailer (his 3rd RV to date). Check out more of his RV adventures, gear reviews, and outdoor advice at thebackpackguide.com.

RV life is much more comfortable when your RV air conditioner works efficiently. A functional AC unit is also essential for keeping the temperature inside your RV safe for pets and humans, especially in hot and humid climates.

Like all RV appliances, your AC unit requires you, the RV owner or renter, to operate and maintain it properly. This guide will teach you the basics of air conditioner use and maintenance by answering the most commonly asked questions about RV air conditioners

How To Use an RV Air Conditioner

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Photo by Camping World

The basics of safe AC operation begin with ensuring you have ample power supply to run your air conditioner. Before moving on, let’s answer a few questions: 

Can You Run an RV Air Conditioner on 30-amp Power?

If your RV requires 30-amp service, that will be enough to run your RV air conditioner. If your RV has multiple AC units, you’ll likely need 50-amp service to run both (or all) units. If your RV requires a 50-amp service, you may be able to use a 30-amp adapter to run a single air conditioning unit, but not multiple.

Your best bet for safely running your RV’s air conditioner is connecting to the electrical service your RV is designed for.

Can You Run an RV Air Conditioner on 15-amp Power?

Theoretically, 15-amp power is enough to power an average air conditioner. The problem is figuring out whether your specific AC unit is “average.” You’ll need to know the exact amperage required for your unit. If you have a larger unit that draws more than 15 amps, you won’t be able to run your AC on 15-amp power.

Even if your AC draws less than 15 amps, you may be unable to run any additional electrical appliances without overloading the circuit. For example, the combined draws of your AC unit, RV refrigerator, and electric water heater may be enough to trip a breaker. 

There’s also the question of surge watts versus running watts. Even an AC unit that draws less than 15 amps when running may draw more when starting up, resulting in a tripped breaker. 

To combat this issue, some have gotten away with installing a soft-start device or manually soft-start by turning on the fan for about 30 seconds before switching to the lowest AC setting and working your way up from there. 

However, installing soft start devices or manually attempting to operate an AC with less than the designated power supply minimums may void your warranty, cause damage to the equipment, and possibly result in fire. 

Bottom line: your best bet for safely running your RV’s air conditioner is connecting to the electrical service your RV is designed for.

Can I Run My RV Air Conditioner on 120?

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Photo by The Toidi via Shutterstock

Standard 120 electric power supplies about 15 amps. So, running your AC unit while plugged into a standard 120 outlet is possible if your AC draws less than 15 amps and you’re not running too many additional RV appliances simultaneously. 

The problems are the same as running on a 15-amp shore power connection. You’ll need to consider surge watts, you won’t be able to run many other appliances, and you’ll need to know exactly what else is drawing on that circuit. If someone plugs a box fan into an outlet on the same circuit, it could be enough to trip the breaker. 

Safe AC Usage Tips

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Photo by Camping World

Now that you’re familiar with AC power considerations, here are a few tips for safe use: 

  • Turn off all appliances before starting your air conditioner. AC units draw more when starting up (surge watts) than they do once they’re operating (running watts). Turning off appliances reduces the chances of overloading a circuit when the unit starts. 
  • Inspect the shroud regularly. The shroud protects the AC components mounted on your roof. Check it before and after each trip to ensure it isn’t cracked or missing. Cracks allow dust, moisture, and other debris to degrade sensitive AC components.
  • Keep doors and windows closed. Minimize the stress on your unit by trapping cool air in and keeping warm air out. 
  • Park in the shade. This also reduces how hard your air conditioner needs to work by limiting your RV’s exposure to direct sunlight.

How to Clean an RV Air Conditioner

The basics of safe AC operation begin with regularly inspecting and cleaning the unit’s air filter. Here are some tips to help:

How to Clean an RV Air Conditioner Filter

Inspecting and cleaning your air filter should be done every 3-4 months. To clean the filter, either rinse with water and allow it to dry completely or vacuum out loose debris before rinsing and drying.

Here’s a complete guide to maintaining your RV’s air conditioner for more AC maintenance tips. 

The Top Questions About RV Air Conditioners

Let’s explore these common questions to learn about AC units and how to responsibly cool your RV. 

How Many Amps Does an RV Air Conditioner Use?

The average RV air conditioner draws between 11 and 16 amps, but there are units (smaller and larger) that fall outside that range. Energy efficiency also comes into play. You can have two AC units of the same size, but the more efficient model will usually draw fewer running amps.

Here’s a quick breakdown of average AC amp draw relative to unit size in British thermal units (BTUs):

Amp ratings are listed for 70℉. Add 1 amp for every 10℉ outside temp above 70. 

AC CapacityRunning Amps
5,000 BTU~4.35
6,000 BTU~5.22
8,000 BTU~6.96
10,000 BTU~8.70
12,000 BTU~10.43
13,500 BTU~11.74
15,000 BTU~13.04
20,000 BTU~17.39

How Many Watts Does an RV Air Conditioner Use?

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Photo by Camping World

Calculating AC wattage requires multiplying amps by voltage. AC units run on a 120-volt circuit, which you can multiply by the unit’s amperage to convert to wattage. You’ll notice that you can also divide a unit’s BTU rating by 10 to get an approximate measure of running wattage.

This is helpful when determining if you can safely run your air conditioner with a generator, which usually offers a wattage rating versus an amperage rating.

Here are some average wattage ratings by AC size: 

AC CapacityRunning Wattage
5,000 BTU500
6,000 BTU600
8,000 BTU800
10,000 BTU1,000
12,000 BTU1,200
13,500 BTU1,350
15,000 BTU1,500
20,000 BTU2,000

Will a 3500-watt Generator Run an RV Air Conditioner?

The short answer is yes, for most. But you’ll need to know your unit’s surge and running watts. Larger units will draw more wattage and may hinder your ability to run other RV appliances, even with a 3500-watt generator. 

Here are some generator size recommendations based on your RV’s electrical demands: 

  • 30-Amp RVs: Minimum 3,500-watt generator
  • 50-Amp RVs: 6,000 to 8,000 watt generator for RVs with dual ACs; 10,000 to 12,500-watt generator for RVs with three ACs.

Check out more tips for choosing the right size generator for your RV.

How Long Can You Run an RV Air Conditioner?

Most RV air conditioners last 6-8 years if maintained properly. The more diligent you are with service and maintenance, the longer you’ll be able to run your unit. 

When camping, you can run your AC 24 hours a day. You’ll just want to use a modest thermostat setting that allows the compressor to cycle on and off periodically. For larger RVs with two or three units, you can cycle between them to give the units intermittent breaks. 

Having a consistent power source is the most important thing to keep your unit running efficiently. This isn’t an issue when you’re plugged into 30 or 50-amp service, but you’ll be limited to your generator’s run time if powering your AC using an appropriately sized RV generator. 

How Do I Make My RV Air Conditioner Colder?

If your air conditioner isn’t lowering the temperature inside your RV to a comfortable level, here are a few things to try: 

  • Adjust the thermostat. It could be as simple as telling your unit you want it to be colder inside your RV.  
  • Move to a more shaded location. Reducing your RV’s exposure to direct sunlight will make your AC more effective because it won’t have to work as hard. 
  • Add insulation to roof vents and windows. This traps cool air inside instead of allowing it to escape. 
  • Clean and/or replace the air filter. Insufficient airflow reduces your air conditioner’s effectiveness. 
  • Clean the coils or fins. Clogged condenser or evaporator coils will also reduce AC efficiency. These should be checked and cleaned every other year. 
  • Check your power supply. Insufficient power will cause your AC to operate below its cooling capacity. 
  • Minimize the number of occupants. Our bodies give off heat. The more people you have inside, the harder your AC works to cool things down. 
  • Cook outside. Easier if your RV features an outdoor kitchen, but worth it to keep things cool inside your RV. 
  • Shower in the bathhouse. Eliminates steam and condensation from hot water…unless you like cold showers. 
  • Minimize the use of appliances and electronics. Every appliance in your RV gives off heat when it’s on. Reducing appliance and electronic usage will make life easier for your air conditioning unit.

Read our complete tutorial on how to improve the performance of your RV’s air conditioner.

What is the Smallest RV Air Conditioner?

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Photo by Camping World

Roof-mounted units are the most common type of air conditioner for RVs, but there are also small portable and window-mounted units. These are great options for RVs without AC or for supplementing an existing RV air conditioner. NewAir and EvaPolar are two top brands for small RV air conditioners. 

Find small portable RV air conditioners in our complete selection of RV AC units. 

Can You Add a Thermostat to an RV Air Conditioner?

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Photo by Camping World

Most AC units have a built-in thermostat or are wired to a wall-mounted thermostat in your RV. Aftermarket residential thermostats rarely work with RV air conditioners, and while upgrade kits are available, they must be from the AC’s manufacturer and be designed specifically for your unit.

These kits will likely require the installation of additional components that allow them to communicate properly with your AC. If your thermostat needs to be replaced, your best bet is to consult the owner’s manual and wiring diagrams for your model and contact your local Camping World Service Center.

Does RV Height Include the Air Conditioner?

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Photo by Camping World

Most RV manufacturers list heights measured from the ground to the highest point, typically your AC unit. A potential exception would be if the base model doesn’t include an air conditioner, but one is available as an upgrade. In that case, the listed height may not include the air conditioner. 

Can You Run an RV Air Conditioner While Driving?

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Photo by Camping World

You’ll only be able to run your RV’s air conditioner while driving if it’s equipped with a built-in generator and that generator is running. You should NEVER run a portable generator while driving in an attempt to power your air conditioner. If you’re riding in the cockpit, the dash AC should be enough to keep you and your navigator cool until you reach your destination. 


Hopefully, you know a lot more about air conditioners for RV use, how to use them, and how to ensure they keep your RV cool and comfortable. If you feel like you need to upgrade your AC unit, check out our full collection of RV air conditioners

Do you have any additional questions about RV air conditioners? Let us know in the comments below. 

And if you’re still learning the ins and outs of RV maintenance, check out our downloadable RV ownership and maintenance booklet!

  • Comment (39)
  • Kenny says:

    How can you safely test your ac in the winter time to make sure it is working? Outside high temp is 45°. Inside temp is 65.

    • Hi Kenny,

      I’d like to better understand what you’d like to test. Are you just wanting to fire up your A/C to make sure it’s producing cool air? Or are you interested in testing temperature, air flow, and sound output?

      I’ve seen folks use an anemometer (air speed) and a decibel meter to test their A/C’s operation in addition to a “feel test” to ensure it’s producing cold air. Let me know what exactly you’re wanting to test and I can hopefully provide further direction.

      Thanks!

  • Kim Johnston says:

    We have a 2009 Winnebago Vista 26P. The a/c was working fine at home and we drove to a campground an hour away and now it won’t cool. Campground checks all electric outlets and they were fine. We checked all breakers and fuses and they are all good. Is there a rest button somewhere for this a/c?

    • Paul says:

      Hi, not sure if this helps but, I ran into that issue myself and found that if the a/c fan is not set to auto and the high speed fan is on, then the until won’t cycle the compressor on just causing air to blow from the high fan setting. That’s how I learned about both my G.E. a/c units. God bless

    • Hi Kim,

      I reached out to our technical service team to get their thoughts. Here’s their reply:

      Did it work when you got back home? There are many reasons that the power at the campground may have caused the problem: low voltage, reverse polarity, open ground, or even high voltage. Next time this happens, unplug the shore cord and try it with the onboard generator. If it works, the campground power is the issue. If nothing works at all since the trip, the outlet at the campground or an RV upstream could have been supplying 240VAC resulting in damage to the system. Did you leave the battery disconnects on while camping? The A/C system requires 12VDC for control power.

      Let us know if you have any follow up questions!

  • Mike Tiner says:

    I have an older Domitic (1993) forced air. On the inside of unit I remove the filter, then the plastic cover. There is the control box that has the wiring coming out of it. There is one with plug on it. Where does it plug in? Thanks.

    • Hi Mike!

      Can you find a model number or any other identifying information on your unit?

      With that, I can attempt to look through Dometic’s archived manuals to see if I can find the applicable one for your unit.

  • Aimon says:

    Jayco 195 2023
    AC. Turn off them self . Ac stop all
    And I can’t turn it on.

    What should I do?

  • Ken says:

    Hi I have an Arctic Fox Silver 5th wheel and lately with the warmer weather we are having the single 13,500 btu unit is not quite up to it as well. The unit is pre-wired for a second unit in the bedroom which would take the place of the fantastic fan there. I have just started to look into doing this and it can be a bit confusing. I am handy enough to do this install myself as it’s pre-wired and the hole is already there. I’m trying to get my head wrapped around what I will need to purchase. I think I would need the compressor unit with cover for the exterior and just the control cover inside with it being vented only from that part of it, correct ? Only other thing would be the btu,’s needed for the second unit. I believe the area of this RV is 295 and I wouldn’t really need another 13,500 unit but maybe around 10,000 btu’s ? Also the next question is what brand or model should I be looking for and any advantage of looking at the heat pump style of unit, thanks in advance !

  • Karen Hargis says:

    Will a ac unit and a heater unit from a 2008 Sunnybrook Bristol bay fit a 1997 travel supreme ??? Mine went out and they are parting out the 2008 ???

    • Hi Karen,

      This is a tough one to answer. The short answer is probably, “I’d need more information on the makes of the specific appliances.” But I reached out to our technical service team to see if they had any thoughts. Here’s their reply:

      In general, all manufacturers have many different models. They will have a chart on their respective webpages to show which components are compatible with one another. Be aware that most roof air conditioners are a three-part system: the roof unit, ceiling assembly, and thermostat and all must be properly matched. The prewiring in the coach must also match the set up. Even if all three are the same in both units, the 11 year separation will likely mean the revisions are incompatible.

      You can also reach out to our renovation department to get their opinion or ask any follow up questions: https://rv.campingworld.com/rv-collision-renovation

  • Haylea says:

    Hi I have a fifth wheel I have been having trouble with my air conditioner in the front bed room it shut off when it 98 out side and when it get cooler at night it still sometime shuts off what could be wrong with it and how could I fix it

  • Holly says:

    Great post! Air Conditioners truly bring a breath of fresh air to the world of mobile living. Your blog eloquently captures the significance of these cooling champions that turn caravans into comfortable sanctuaries even on the hottest days.

  • Jennifer Bogle says:

    Hi David! We have a 2013 Tiffin Allegro Red with two roof top ACs (Coleman Mach 8). When connected to shore power, they work fine. When boondocking, they work fine using the generator. However; when we run them while driving using the generator, they cool for the first 10-15 miles, but then warm air starts blowing out. We’ve tried driving at slower speeds; we’ve tried only running one AC and closing doors in the rear of the coach. We start the engine, then generator, wait a few, then turn AC on to HI. We’ve taken it to a few places, but no one can figure out why. We are in 100 degree heat, so I don’t expect it to cool down drastically. Any suggestions?

    • Hi Jennifer,

      Sorry for the delayed reply, but I wanted to reach out to our technical service team to get their thoughts. Here’s their reply:

      We wish we could get our hands on it for a better look, but the system is pretty basic. You’ve already established that the shore power, generator power, and air conditioners work great when stationary, so it pretty much has to be related to airflow over the roof units. Things that come to mind are a speed induced vacuum or pressurization that starves the condenser fan and reduces or stops airflow across the outside coil. The same pressure anomalies could cause cooled discharge air to be forced into the return air plenum resulting in icing of the inside coil. The freeze probe in the inside coil might also sense temperatures below the cut off point due to this cold air infiltration which would result in the compressor shutting down.

      You might benefit from scheduling an AC diagnostic at one of our service centers: https://rv.campingworld.com/rv-service-maintenance#js-anchor-locations

      Hope that helps!

  • Dave White says:

    My Colman/ Mach AC unit runs great with my 3500 inverter or on my shore power 15 amp outlet. Recently my shore power breaker trips several times and eventually will start the AC. Also my inverter struggles to start the unit as well. I purchased my used trailer 3 years ago, it is 2011 Sprinter so I have no idea how old the AC unit is. Do I need to replace the unit or replace an internal part?

  • Cindy Barnes says:

    I am plugged into shore power but when the power went out during a storm my AC did not kick back on when the power came back and I lost the time on the microwave….does that mean my batteries are low or shot?

    • Hi Cindy,

      It’s more likely that you popped a circuit breaker or blew a fuse when the power went out. Have you checked the breaker on the shore power source, as well as the breakers and fuses on your RV’s circuit panel?

  • Glen says:

    Our AC units, the main one in particular, don’t seem to be cooling well in the triple digit temperatures here in Texas. Our 5th wheel is parked for the next two years with shade unavailable. Is this normal in extreme heat?

    • Hi Glen,

      Yes, this is normal operation for what you are describing. Try starting your AC earlier in the day, run the fan speed on high, and verify even air flow from all vents (you can use an anemometer for this). The main unit may need servicing. From your description, we’re guessing that the main unit is in the main living area and the other unit is only cooling the bedroom? RV ACs are only expected to cool 20 degrees less that the ambient temp within the RV.

      If yours continues to struggle, I’d schedule a service appointment: https://rv.campingworld.com/rv-service-maintenance

      Let us know if you have any follow up questions!

  • Lakin Zoe says:

    When selecting a generator for your AC unit, compare the starting and running wattage to the generator’s capacity. Simply refer to the AC unit specifications to make an informed decision. In general, a 2,000 to 4,000-watt or higher generator should suffice for most RV AC units.

  • Paul Dane says:

    We have a 2022 Coachmen Sportscoach and the a/c runs great on power but when we try to run it while traveling using the generator the a/c won’t run.

    • Hi Paul,

      I ran your question by a few of our technicians and they’d have several follow up questions. They replied that a quick test would be to see if both breakers on the gen set are in the on position. They’d guess that a circuit breaker is popped on the generator not allowing it to provide power to that circuit, but it’s always hard to guess without all the facts.

      Your safest bet is to schedule a service appointment for a general AC diagnostic: https://rv.campingworld.com/rv-service-maintenance

      Let us know if you have any follow up questions!

  • Richard Matthews says:

    Do I need to have my slides open to run air conditioner, I just cooling things down while getting ready to travel and cooling the Refrigerator.

  • Shelly says:

    I am having trouble with my 2023 Astoria FW. We have two a/c units (one in the main bedroom up front and one in the back bedroom) and have been running them for about 3 hours now. Both bedrooms are cool, but the living room/kitchen area in the middle of the rig is still soooo warm. Even with the I interior doors open so let the air flow through, the middle area will not cool down. All windows are closed and we have even tried opening the vent on the roof to see if that helps, but it is now working!

    • Hi Shelly!

      It really should go back to the dealer for inspection and testing. It sounds like all of the airflow is going to the ends as it follows the path of least resistance. The dealer will be able to determine if the vents are in the correct locations, that there are the required number, and that there are no obstructions. It may be necessary to add additional vents or baffles to balance the airflow and by default, comfort zones.

      Here’s where you can find the dealership nearest you: https://rv.campingworld.com/locations

      Hope that helps, but let us know if you have any follow up questions!

      • Kimberly R Vossah says:

        My ac stopped working while battling the three didget heat wave here. Now it will not turn back on. I can hear it click as if it were going to come on but then it doesn’t and no air blowing out? Please help me, what is the problem?

        • Hi Kimberly,

          Have you checked your fuses and breakers?

          Your best bet is to contact your local Camping World Service Center to schedule an AC inspection: https://rv.campingworld.com/rv-service-maintenance

          Let me know how it all works out!

          • Dave says:

            I replaced a control box so that my turnstyle ac knobs are converted to thermostat controlled ac, propane furnace and heat strip. When testing, my newer Mach 3 Plus fan works on low and high but the ac won’t kick on. I ran a 30amp to 20 amp adapter to a 20 amp power cord and plugged in to 20amp plug at my rv storage area. No other electrical appliances were used during test. Any thoughts? Thanks much.

          • Hi Dave,

            I reached out to our technical team and here’s their reply:

            There are a bunch of conversion kits for various models and brands of A/C’s. Without specifics, it’s hard to say for sure, but it’s possible that one or more wires were not connected properly. Even if you followed the directions precisely, there may be a slight variation in his actual product from the instructions. Also, there may be DIP switches or terminal jumpers that are improperly configured.

            Your best bet might be to schedule an AC diagnostic at one of our service centers: https://rv.campingworld.com/rv-service-maintenance#js-anchor-locations

            But let me know if you have any follow up questions!

  • David says:

    I have a new 5th wheel coach with 3 of the dometic low profile ACs
    I recently noticed that if the power goes off, and back on, they don’t auto reset and come back on until you physically turn them on. Is there a setting or something to change this?
    Thank You

    • Hi David!

      There are quite a few logic control systems on the market that manufacturers are utilizing to control today’s systems, acting as the thermostat if you will. Most are all 12-volt DC controlled. This being said, as long as the 12-volt DC remains when the shore power goes away, this should not happen. I would first ensure that the RV’s DC batteries are turned on while using shore power, this way if the shore power goes away the DC logic control system can retain the AC programming. If all is good there, I would need more info on the particular logic control system or thermostats.

      Hope that helps!

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