RV Chill on the Cheap: DIY Cooling Projects That Really Work

We absolutely love traveling in our RV all year long. This of course means dealing with some extreme temperatures from time to time, something that’s easy enough to do in summer as long as we have power hookups and can run the air conditioner. That said, boondocking is one of my favorite ways to camp, meaning we don’t always have access to power.

The good news? There are ways to keep your rig relatively cool even when you can’t run the AC. Here are some of the DIY cooling solutions we have found over the years. 

Understanding RV Heat Gain

First, let’s take a minute to talk about why it is that RVs heat up so quickly. Understanding this might help you when looking for ways to stay cool.

Basically, RVs are insulated very poorly. This means cool air escapes easily and heat enters just as easily. Direct sunlight hits the thin walls and roof and seeps right in, and the windows of your RV can act like magnifying glasses, directing heat into your living space. Add some people and electronics into your tiny space and your RV is going to get really warm really quickly. 

Because of this, your strategy shouldn’t just be about cooling the air down—it should be about preventing heat from building up in the first place. Every degree of heat you block, reflect, or vent means less work for your A/C (and your sweat glands).

Window Solutions: Reflect, Block, and Shade

Let’s start with the windows. If you can block heat from entering through the windows, you will be well on your way to keeping your rig as cool as possible.

Reflective Window Covers

In my experience, sun-facing windows are the worst culprits for heat gain. One of the simplest, most effective ways to remedy this is cutting reflective insulation (like Reflectix) to fit your windows. 

Simply:

1. Buy a roll of Reflectix from a hardware store.
2. Measure and cut to size for each window.
3. Secure with Velcro strips, magnets, or tension rods.

This is a super low-cost solution and can lower interior temps by 10°F in extreme heat. 

Blackout Curtains with Thermal Liners

I’ve found that regular curtains don’t do much to fight against heat. That said, blackout curtains offer a thermal liner that will absolutely help keep heat at bay. Putting up some blackout curtains in addition to Reflectix is an excellent way to ensure your windows aren’t letting in any excess heat. 

Exterior Shade

Another option? Attach shades to the outsides of your windows. These work as sunglasses for your RV, ensuring sunlight never even shines on the exteriors of your windows, meaning it definitely isn’t going to sneak inside. 

Ventilation: Let Hot Air Out, Pull Cool Air In

Ventilation is super important when it comes to keeping your RV cool. As boondockers, we adore our vent fans and roof vents and use them regularly.

DIY Vent Fans

Your roof vents are natural escape hatches for rising hot air, and adding a vent fan turns them into cooling powerhouses. We adore our MaxxAir vent fans, but these can be pricey. Luckily, you can build a budget version using nothing more than a 12-volt computer fan or USB-powered fan mounted in the vent opening.

To build the fan:

1. Remove the interior vent cover.
2. Attach a fan using zip ties or a lightweight frame.
3. Wire it to your RV’s 12V system or run it via USB/battery pack.

You can probably put this project together for less than $40 and it really does work for getting air moving. 

Cross-Breeze Magic

We like to use our roof vents to effectively create wind tunnels, which are amazing for keeping the RV cool. That said, you can actually use portable fans to create an even stronger and more effective breeze. Simply place a fan so it is blowing out of one window while another pulls air in. We have battery operated fans to use for this while boondocking. 

Swamp Cooler (Evaporative Cooling)

Usually, we find ourselves in humid places during the summer. That said, if you’re camping in a dry climate, a DIY swamp cooler can be a game-changer. Basically, this is just a fan that blows air across wet material, cooling it as water evaporates.

You can make your own by doing the following:

1. Use a 5-gallon bucket.
2. Cut holes in the side for PVC elbows (air outlets).
3. Add a small submersible pump and a pad of wicking material.
4. Run a 12-volt or USB fan across the wet pad.

The cost of this project is only about $50 and it can cool an RV by 10 or more degrees in the right environment. 

Roof Hacks: Beat the Sun from the Top Down

Finding ways to keep heat from absorbing into the roof of your rig will also help keep things nice and cool inside. Here are some ways to go about that. 

White or Reflective Roof Coating

The roof of your RV sees the majority of the sunlight that beats down on your home-on-wheels, and a dark colored roof is going to absorb that heat. Combat this by painting your RV roof with white roof coating. 

DIY Steps:

1. Clean the roof thoroughly.
2. Apply the coating with a roller or sprayer.
3. Let it cure for 24 hours.

This will cost about $100 to do, but it is a project that is well worthwhile. 

DIY Shade Awning

We really like to use our awning to block the sun when there’s no shade in our site. It’s effective and easy enough to use. If you don’t have an awning of your own, you can build a simple DIY version using PVC pipe and tarp fabric. Extend it off the sunny side of your RV to shade walls and windows. 

Insulation Upgrades: Stop Heat at the Source

Adding more insulation will also help hold cold air in and keep warm air out. There are a few ways to do this that are simple enough. 

Under-Bed and Compartment Insulation

I’ve noticed a lot of hot air creeping in through storage bays and under-bed compartments. You could line these areas with foam board to add some insulation to the bedroom. 

Door Draft Fixes

Our RV doors have some small gaps around them. I make sure to add weatherstripping or foam tape around edges, and install a door sweep on the bottom to keep warm air out. 

Slideout Covers

Our slideout heats up before the rest of the RV and it can get really toasty. I loved the slide toppers on our previous motorhome because they helped with this. That said, slide toppers are expensive. Instead, consider making your own topper from UV-resistant fabric to block direct sun and keep the interior of your rig cooler.

Shade Where You Park: Nature’s Free Cooling System

Obviously, finding the right parking spot can help keep things cool, too. We always, always look for shade, as this makes an enormous difference. I also recommend situating the smallest side of your RV so it faces the sun during the hottest part of the day. 

Low-Tech Cooling Tricks That Actually Work

Looking for more easy DIY ways to keep cool when camping without air conditioning? Here are some of my favorite tricks. 

Frozen Water Bottles

Freeze a bunch of water bottles and place them in front of fans. As the ice melts, the fan blows cooler air around. Once the ice melts, drink the water to stay hydrated. 

Damp Towel Curtain

Hang a damp towel across an open window or vent. As the air passes through, it cools, creating a super simple swamp cooler. Obviously, this works best in dry climates.

Nighttime Air Exchange

If nights are cooler, open every window and vent to flush hot air out. In the morning, close everything up to trap the coolness inside. I like doing this when we’re camped in the desert because the nights are so cool and refreshing. 

Cooking Outside

We always skip the stove and oven on hot days because both add major heat inside. Instead we use a propane grill, a camp stove, or even a solar oven outside—or just stick to cold meals. 

As you can see, there are plenty of ways to keep your home-on-wheels cool even when you can’t turn the A/C on. By using these tricks and planning your route strategically—the further north you can be during warmer months, the better—you should be able to stay cool all year long!

Facebook
Twitter
Pinterest
Reddit
LinkedIn
Email