How Does the Air Conditioning System Work in an RV?

One perk of RV camping is having an air conditioner to keep you comfortable in warmer temperatures. Recently, my RV air conditioner couldn't keep my rig as cool as I wanted. So I had to do some research about how air conditioning works inside an RV.

Simply put, an RV air conditioner works by removing heat from the air inside your RV. The AC unit draws in the hot air, expels heat outside of the RV, and pushes the cool air back into your RV through air vents. The basic components of an air conditioner that make this process happen are:

  1. a compressor
  2. a condenser
  3. an evaporator
  4. fans
  5. refrigerant liquids

Please read on to find out what I learned about how RV air conditioning works. I'll also share tips for helping your AC run more efficiently and how to power your air conditioner without electrical hookups.

camper travel summer time interior home sea ocean view, How-Does-the-Air-Conditioning-System-Work-in-an-RV

How RV air conditioning works

As I mentioned before, RV air conditioners work by removing heat, not creating cool air.

The RV AC system is a closed system, which is different than the AC in your automobile or home.  This means that the refrigerant fluids (similar to the Freon in our cars) are sealed up in the tubing, with no exit or entrance.  They continually cycle through the system, to expel hot air and push cool air back into your RV. I'll describe this process in simple, layman's terms.

The compressor works to circulate, heat, and compress refrigerant vapors inside the AC unit. When the vapors are pressurized at a high enough level, they will give off heat in the condenser.

The condenser works to take the heat out of the air and push it out of the RV.  Inside the condenser, the refrigerant vapors are being cooled down and turned back into a liquid.

This cool liquid travels to the evaporator, which is absorbing heat from the warm air inside the RV. This hot air gets washed over the cool coils of the evaporator, and the temperature of the air drops. This cool air is blown back into the RV through the vents.

As the refrigerant liquid absorbs heat in the evaporator, it turns back into a vapor so it can go back into the compressor and recycle through the system.

RV Air Conditioners Need a Lot of Energy

In this simplified description, you can see why the process of refrigeration inside the AC unit requires so much energy. Think back to science class and the physical states of matter. Changing the refrigerant gas to a liquid, then back to a gas again requires a lot of energy.

In air conditioning, the unit used to measure energy is a BTU. The more BTUs, the more powerful the AC unit will be. Most RV air conditioners have between 11,000-15,000 BTUs.

The longer your RV, the more BTUs you'll need to cool your rig down. This is why longer RVs tend to have two AC units installed. If you are over 32 feet, it's likely that one AC unit is not going to be enough for your needs in warmer camping weather.

Realistic expectations

RV air conditioners are simply not going to perform as efficiently as a home AC unit, so we need to adjust our expectations a little. Experts say that an efficient RV air conditioner should output air that's between 16-22 degrees cooler than the air coming into the AC unit.

For example, let's say the temperature inside your RV has reached 90 degrees while sitting in the sun one day. When you turn on your AC, if it functioning properly, it should put out air that is close to 70 degrees.

It's going to take time for the air in your RV to completely cycle through the AC unit, producing a comfortable inside temperature. However, there are some things you can do to help the AC unit work more efficiently.

Tips to help your RV AC run more efficiently

rv camper air conditioner repair by mechanic

Here are a few quick tips to help you run your RV air conditioner in a way that's efficient and saves on energy (super important when you're running on generator power!) and generally keep your rig cooler.

Make sure your AC filters are clean

Proper airflow is very important in keeping your AC running efficiently, and dirty filters will slow that process down. Filters can collect dust quickly while on the road, so check your cold air return and filters every couple of months.

Use fans to circulate cool air

An RV air conditioner tends to cool up the air right in front of the vent, creating a pocket of cool air.  Ceiling fans such as these models can help disperse the cool air throughout the room and bring the temperature down more quickly.

Park in the shade whenever possible

man holding steering wheel driving car

Use your awning to create more shade around your RV.  The more you can keep the RV from heating up inside, the less your AC will have to work to remove the heat.

Close doors to parts of the RV that you're not using

Consider closing the vents in bedrooms that you're not using during the day so the AC can push all of the air into the room you're sitting in.

Avoid adding extra heat into the air

Cooking or using the RV microwave will add extra heat to your interior space. This will just offset the cool air being released by the AC unit. While running the air conditioner, try to use your outdoor kitchen or grill to cook food outside the RV.

Insulate your RV

Consider tinted windows or double pane window options for your RV to better insulate your rig against warm temperatures. Pull down the shades and create tight seals in places where heat can get into your RV.

Read more about true four-season RV's here. They're also better at keeping the heat out, not just the cold.

Can I use my air conditioning when I'm boondocking?

rv motorhome camper interior bed room area

The answer is yes, but only if you have an alternate source of energy that will supply the amount of electricity you need to run the AC unit.

When connected to 50 Amp electrical hookups in a campground, it isn't a problem to run one or even two AC units in your RV. With a 30 Amp hookup, you can probably run one AC unit, if you are careful about not running other high-use electrical appliances at the same time.

Boondocking, however, is camping without any electrical hookups. Contrary to what your RV salesman may have told you, the battery inside your RV will not be able to provide you with enough energy to run your AC unit on its own. You will not be able to boondock and use your air conditioning without another power source.

There are a few options for getting electricity into your RV when boondocking. The main power sources that RVers choose is a generator or solar panels. Extra batteries may also be used to store additional energy.

Choosing a generator

In order to run an AC unit, you will need a powerful generator.  The air conditioning system requires more energy than any other appliance inside your rig. If you know that you need to have air conditioning and will not be connected to an electrical hookup, you need to invest wisely in a generator that will meet your needs.

To run one AC unit, a suggested starting point is a mid-size generator with 3000 watts. Alternately you could purchase a pair of smaller, 2000 watt generators to power one AC unit.  Check out this guide on types of RV generators to learn more about the right generator for your needs.

What about solar power?

camper travel summer time interior home sea ocean view

Fulltime RVers who have made a considerable investment in solar panels, an inverter, and extra batteries have found ways to run their AC from solar energy.

Solar power is a big up-front investment and requires many calculations in order to purchase the solar panels, inverter, and extra batteries needed for your rig. The air conditioner is a large appliance and will require more energy to run than other appliances in your RV. We recommend doing further research on your electrical needs and the different products available before committing to solar as your AC's power source.

Read more: Are Solar panels worth it in an RV?

Staying comfortable in your RV is worth the commitment of a reliable power source to make it run smoothly.  Maintaining your air filters and following energy-saving tips will also keep your RV air conditioner working at its best.  Wherever you camp, we hope you stay cool this summer!



How Does The Air Conditioning System Work In An RV?

Share this article


  1. Steps to Making Your Motorhome’s AC Quieter: One of the easiest ways is by checking all the system’s components and parts for any signs of looseness, or if the vents are filled with dust and other particles that can make your air conditioner work harder and create noise. AC units have many components that can contact one another, producing vibration and noise. You should cover the hoses and pipes to prevent them from rubbing against one another or also insert foam or rubber cushions between the RV AC unit and the RV rooftop. Another potential source of AC noise is the coils. I think you should inspect the AC coils and check their integrity. Besides that, a broken or faulty fan motor can also cause a loud noise. Finally, you might want to check other components for leaks if you want a quieter motorhome AC.

  2. A noisy RV air conditioner can mean different things, including loose hardware, dirty components, or a unit begging for a replacement. Identifying the main cause and doing regular maintenance should resolve the problem.

Leave a Reply

Your email address will not be published. Required fields are marked *