How Do RV Air Conditioners Work?

Have you ever sat inside an RV, enjoying precious cool air pouring in from your A/C unit, and wondered, “Exactly how do RV air conditioners work?” Well, you’re not alone—whether you’re an RV owner or an aspiring buyer. 

Understanding how critical RV systems, like your air conditioning unit, operate will help you troubleshoot issues when they arise. Knowing what to expect from your air conditioning system also alerts you when it isn’t operating as expected, giving you a jump on critical maintenance before a more expensive repair is required. 

So, let’s detail the basics of running an RV air conditioner.

How Do I Turn on My RV Air Conditioner?

All RV air conditioners are operated by a control board or a wall-mounted thermostat inside the unit. On many smaller campers, the controls for the A/C fan and the thermostat are directly on the unit’s interior ceiling panel. 

On other RVs, the air conditioner operates from a digital or analog wall-mounted thermostat. Fan controls typically include:

• Fan Only
• A/C (i.e., Cooling)
• Heat (if the unit has a heat pump or heat strips) 

The thermostat control may allow you to set a specific temperature. But it may also feature a dial that simply allows you to adjust hotter or colder, depending on your preference.

For your information, a heat pump is essentially an air conditioner in reverse. It is coupled with an RV furnace via the control board because the heat pump won’t work in freezing temperatures when the furnace can take over.

Technician Tip: Consult your owner’s manual if you’re unsure which type of control your RV’s air conditioner uses. 

How Does an RV Air Conditioner Work?

An RV A/C unit removes heat from the air inside your RV, cooling down the interior temperature. It uses a refrigerant in the unit’s evaporator coil, which absorbs heat. The pumping action of the unit’s compressor then pumps the heat out of your RV to the condenser coil on the RV’s exterior—either the roof, basement, or sidewall—and the heat dissipates.

Here’s a step-by-step breakdown of what happens when you turn your RV air conditioner on: 

1. The evaporator blower draws warm air into the air conditioner through the return air grill and filters it over the cold evaporator. 
2. The refrigerant extracts heat and moisture from that warm air. 
3. The warm air changes the refrigerant’s state from a liquid to a gas at low pressures.
4. Cooler air is returned to your RV’s interior.
5. The gas passes through the accumulator to the compressor, compressing it to a higher pressure.
6. That high-pressure gas goes into the condenser coil, where cooler exterior air is pulled in through louvers in the air conditioner’s shroud and passed over the coil. 
7. That cooler air transforms the high-pressure gas into a liquid that is metered into the evaporator. 

Simply put, an RV air conditioner removes hot air from your RV. It doesn’t necessarily create and pump cool air in. The laws of thermodynamics aside, when it works properly, your RV air conditioner regulates the temperature inside your RV to your desired thermostat setting. 

Can an RV Air Conditioner Run Continuously?

An RV air conditioner will continue to run as long as it has an ample power supply. A/C units will cycle intermittently to regulate your RV’s interior temperature. The fan will run continuously, but the compressor will cycle to maintain the temperature according to your programmed thermostat setting. 

While your RV A/C can run continuously, there are some practical concerns to consider. 

The first is whether you’re paying for electrical service. While your electrical usage won’t be metered for most short-term stays at RV parks, the same cannot be said for monthly rentals. Many RV parks charge for electrical service on long-term site rentals. In this case, the more you run your air conditioner, the higher your energy bill goes.

The second is longevity. Simply put, the more you run your A/C unit, the more wear and tear it will sustain. More frequent use also increases the frequency of periodic air conditioner maintenance. Most RVers service their air conditioning system annually, but you’ll need to do so more frequently if you run your A/C continuously. 

The third is short-term viability. An air conditioner that runs continuously is more likely to experience the evaporator coil freezing up. When this happens, it can prevent cool air from returning to your RV’s interior. The result is an air conditioner that isn’t doing its job and will require an extended shutdown to thaw. 

Your best practice is to run your A/C strategically and periodically to keep your RV comfortable. You can also use these RV climate control tips to keep your RV cool without A/C. 

What Is the Best Setting for an RV Air Conditioner?

The ideal setting for your RV air conditioner depends on your climate control preferences and the options available on your specific unit. However, we can offer a few important tips when selecting your air conditioner settings. 

• A lower fan setting will put less strain on the blower motor over time. However, you’ll likely need a higher fan setting on particularly hot and humid days.
• If your RV is equipped with an Auto fan setting, it can be the most eco-friendly option. The fan will cycle on when the system is cooling and off when your programmed thermostat setting is reached.
• Many RVers claim that 72℉ is their ideal A/C thermostat setting, but that will likely depend on the exterior temperature. 
• On average, the air returning into your RV from the A/C will be roughly 15-20 degrees cooler than the outside air temperature. 

Do RV Air Conditioners Run on Propane?

It is uncommon for RV air conditioners to run on propane. They are not like their counterpart—RV refrigerators. Running an air conditioner on propane isn’t impossible, but it would be more expensive, complex, and logistically challenging than the standard system you’ll see on factory-manufactured RVs. 

How Do You Reset an RV Air Conditioner?

Some RV air conditioners have a small reset button. Others can be reset simply by turning the power off and switching off the associated breaker or removing the associated fuse for several minutes before returning to the operational position. 

Technician Tip: Due to the many RV A/C manufacturers today, it’s best to consult your owner’s manual for reset instructions and troubleshooting guidance.

How Long Do RV Air Conditioners Last?

With proper maintenance and protection during the offseason, RV air conditioners can last at least 6-8 years. However, they can require an air conditioner replacement much sooner than that if not maintained properly. 

Here are some quick RV air conditioner maintenance tips: 

• Get an annual A/C inspection. RV Techs will typically inspect the shroud and seals around the unit, test the air return temperature for that average change, and more.
• Keep the filter clean. Cleaner air passing through your A/C reduces the chances of wear and damage to interior components.
• Cover it in storage. Use an air conditioner cover to protect the exterior part of the unit from moisture, debris, and other elements. 
• Consider a soft start. An air conditioner soft start reduces the power required for starting the A/C unit, protecting the unit when less power is available, such as when connected to a portable generator.
• Track your maintenance. Keep a record of regular inspections and maintenance procedures. This helps you paint a clear picture to the next RV technician who works on it—and it can also increase your RV’s resale value by demonstrating your diligence to potential buyers. 

Has it been more than a year since you had your RV air conditioner inspected? 

Contact our Service Department today.

While this article focused on the basics of how RV air conditioners work, here are a few more resources to help you learn about and care for your RV’s A/C unit: 

• All Your Questions About RV Air Conditioners Answered
• Improve the Performance of Your RV Air Conditioner

What questions do you have about how RV air conditioners work? Let us know in the comments below.