Passive Cooling: How to Beat the Heat in a Van

I spend my winter in the desert and sometimes it gets hot. This photo shows some of my methods to stay cool: 1) Shade cloth draped around the trailer 2) Plywood over my roof 3) Roof vents 4) ADCO windshield cover on the van 5) Shade cloth between the trailer and the van to make a shaded porch to sit under outside.

I’m writing this in July and much of the country is sweltering under oppressive heat, so it seems like an appropriate time to write about staying cool in a van. Before we go any further let me say staying cool is the most difficult aspect of living in a van and the best you can hope for is to make it bearable; it will never be pleasant or good! There are two kinds of cooling for your van:

1) Active Cooling is when you are creating cold air with an air conditioner and pumping cold air into the van. Because you are creating cold air, you can reduce the temperature to almost any temperature you want if you spend the money. Active cooling is difficult because you have to find room for the air conditioner and then you have to find a large source of electricity for it. The power almost certainly must come from either a generator or being hooked up to the city 110 power grid (commonly called shore power). With a van the most practical solution is a very small window or portable air conditioner powered by a generator. It is possible to run it off solar, but it is difficult and expensive. You’ll need:

  • A very well insulated van.
  • The smallest air conditioner you can find–500 watts or less.
  • A minimum of 800 watts  of solar and 8 golf cart batteries.

With this system you are creating more power than the air conditioner draws but it’s going to be expensive, need a lot of room on the roof and the batteries will be very heavy and take a lot of space. And even then you can only run the air conditioner sporadically and a minimal amount at night.

The bottom line is Active cooling isn’t a viable option for must of us, we need something cheaper and easier.

2) Passive Cooling is when you are doing everything you can to keep heat from building up in the van. However, the best you can hope for is that the inside temperature is the same as the outside temperature. For example, if it’s 100* outside, it will be 100* inside. That doesn’t sound very good but consider if you didn’t use passive cooling techniques, it could easily be 130*-140* inside–that’s a big improvement and worth the effort!!

This post is only about Passive Cooling steps you can take because they are all relatively cheap and easy and the average person can do them. Let’s take a look:

How you Park the Van:

How you park can make a big difference. Your windows allow the most heat into the van and your side door allows the most cooling so you want to try to park the van so the least heat comes in from the windows and the most heat can escape through the side door. Since I have a cargo van, I try to park East-West with the windshield facing due west; that way the drivers side (which has no windows) faces south, and the side door gets no sunshine and can be open all day.  To keep heat from coning in through the windshield and drivers window, I use an ADCO windshield cover that completely covers the windshield and drivers window. By parking with the front pointed to the West and using the ADCO cover, the only windows exposed to the sun are the back door windows and they are tinted very dark.  Passenger vans will be different, just try to park with the fewest windows exposed to the sun and the most doors open into the shade.

Roof Rack to Shade the Roof: 

This is a fairly cheap and easy method of cooling the van because your roof is in the shade 100% of the time. The easiest way is to buy a ladder rack and use 2x4s and plywood to cover the roof. If you keep it low enough no one will be able to see it and it won’t hurt your stealth. The sun and rain will destroy the wood so you want to paint it very well. This is the ladder rack I use on my van and it costs $82 on Amazon:  Pro-Series 500 lbs. Capacity Van Rack

I covered the roof of my trailer with plywood so it’s always in the shade. You can also see I have two vents with covers and a tarp to cover the south wall of the trailer which leaves my side door open into the shade of the van. I have very good passive cooling.

Paint the Roof:

If you have a dark colored van, you can keep it cooler by painting the roof with a special elastometric paint like my friend did in the below picture. She used the Kool-Seal brand but there are several good ones. You can buy it at Walmart or Home Depot. It’s very easy to do, you just pour it on and roll it evenly with a roller. The hardest part is scrubbing  the roof clean. Buy Kool-Seal from Amazon here: Kool-Seal Elastomeric Roof Coating, 1-Gallon

A friend of mine painting her roof with Kool-Seal to keep it cooler.

Install a Roof Vent:

Without doubt one of the best thing you can do to cool the van is install a vent. Warm air rises so it automatically  will exit from the van. You can buy vents with powered fans in them and they are an excellent choice. They can be set to run inside or outside and they will remove a lot of air very quickly. A non-powered vent will be about $40, a basic powered Fantastic Fan will be around $150. They aren’t hard to install but paying someone to install one will be expensive. Get one from Amazon here: Fan-Tastic Vent 3-Speed Motor, Manual Crank

A Fantastic Fan at work drastically cooling the van.

Use Portable Fans:

I actually prefer portable fans more than roof fans because they are so much cheaper and you can set them anywhere you want. Having a fan siting two feet away from you aimed right at your face is going to work better than an immovable fan in your roof. I have two fans I carry with me; the first is an Endless Breeze which is made by Fantastic Fan. I’ve been using it for over 10 year and it seems to be indestructible. The other is a Roadpro fan but it is made by O2 Cool. They are a very good, inexpensive fan that is often re-branded as Walmarts Ozark Trail or Roadpro. You can get the Roadpro at any truck stop. Get them from Amazon here: RoadPro 12-Volt/ Battery Portable Fan
Endless Breeze Stand alone Fan

ADCO Windshield Cover:

Something I recommend very highly is an ADCO Windshield cover! They are a heavy vinyl that fits completely across your front-door windows and windshield. To put it on you open one door and slip the pocket over the doors corner and shut the door. Pull the cover over the windshield and open the other door. Slip it’s pocket over that door and close it. It has magnets at the bottom to keep it from flapping in the wind and has a cutout for the mirrors. It works extremely well–far better than Reflectix because the heat never gets inside the van. Another plus is it lets some light through so the  van isn’t as dark as Reflectix which doesn’t let any light through. Mine cost about $45. Get them from Amazon here: ADCO Windshield Covers

Reflectix in the Windows:

For summer or winter, putting Reflectix into the windows of the van is a lifesaver! It will keep the van cooler in the summer and warmer in the winter. There are several ways to do it but the simplest and best is to cut the Reflectix a little big and simply press it into the window frame. You’d think it would just fall out but for some reason it doesn’t. Two other options are 1) to use Velcro to hold it in, or 2) strong magnets taped to the Reflectix and washers taped to the window frame. But compression works so well I recommend you start with it. Buy it from Amazon here: Reflectix 24-Inch by 25-Feet Bubble Pack Insulation

Use Tarps or an Awning to Shade the Van:

A very good option is to drape tarps as an awning off the van or trailer. It has the advantage of being cheap and easy and it also works great in the rain. But, it has two really big disadvantages: 1) you can’t leave it up in a strong wind, 2) it keeps the breeze from blowing through  the van. If you are in the forest you can tie it out to nearby trees and in the desert you can use PVC tubes as tent poles.

I tied this tarp out to nearby trees and it kept the rain off in bad weather and it also put the side of the trailer in the shade in sunshine. It worked very well!

In the picture below you see my high quality awning made by ARB that I installed on my trailer. It works very well, and is fairly easy to put out, but, it won’t stand up to much wind.

My ARB awning and shade cloth to make a very pleasant outdoor room.

Use Shade Cloth in the Desert:

The problem with tarps and awnings is they can’t stay up in much of a wind and the desert has a lot of wind. I got tired of taking it down in every windstorm so I switched to shade cloth instead which is a mesh tarp that lets the wind flow through. It doesn’t shade as well as a tarp would, but it shades very well. Plus, it allows the near constant breeze to blow through the cloth and into my windows. Having the breeze much more than makes up for it not being quite as good a shade.

It’s important that the shade cloth be pulled away from the van. An easy way to attach it is to drill holes through the gutter of the van matching the grommets in the shade cloth and use spring clips carabiners to attach it into the holes. Pull the bottom of the shade cloth out away from the van and use bungee cords to attach it to stakes driven into the ground far enough to hold it far away from the van. Oddly, dark colors are better than light colors as long as it is held out away from the vehicle. Mine is 10 x 16. You can buy one like it from Amazon here: 90% Shade Mesh Cloth, 10′ x 16′

Shade cloth on trailer and van.

Shade cloth on trailer and van.

Have an outdoor room:

If at all possible you want to have an outdoor room where you can go and sit in the shade in the heat of the day while the van is it’s hottest. There are several ways to create one. The first is with an awning for a roof and and shade cloth as walls, and the other is with a pop-up awning like an EZ-Up Canopy. They’re cheap and fairly easy to setup, but best of all they give you good shade during the heat of the day. You can get an EZ- Up canopy from Amazon here: E-Z UP 10 by 10-Feet Canopy

My ARB awning and shade cloth make a very nice outdoor room

An EZ-Up outside the van door also makes a nice outdoor room.

I hope you get some ideas on staying cool from this post. They won’t all work for you because we are all in very different situations, but hopefully some of them will work.

Here are the items I am actually using from Amazon. If you use these links I’ll make a small percentage and it will cost you nothing:

Pro-Series 500 lbs. Capacity Van Rack
Kool-Seal Elastomeric Roof Coating, 1-Gallon
Endless Breeze Stand alone Fan
RoadPro 12-Volt/ Battery Portable Fan
Fan-Tastic Vent 3-Speed Motor, Manual Crank
ADCO Windshield Covers
Reflectix 24-Inch by 25-Feet Bubble Pack Insulation
90% Shade Mesh Cloth, 10′ x 16′
E-Z UP 10 by 10-Feet Canopy

Bob
About

I've been a full-time VanDweller for 12 years and I love it. I hope to never live in a house again!

45 comments on “Passive Cooling: How to Beat the Heat in a Van
  1. tommy helms says:

    A 1 dollar spray bottle from Walmart, filled with water, will help cool you off too. Just spray yourself and sit in front of the fan.

  2. Irv Oslin says:

    Whenever tying off tarps to trees, I use heavy-duty rubber bungees to absorb the shock when the wind blows. On only one occasion has the wind — 40+ mph — pulled out a grommet. Even then, the cording around the edge of the tarp remained intact.

    • Bob Bob says:

      Thanks for the great tip Irv! Yeah, I almost always use bungees in line somewhere when using a tarp. I’ve never had a problem in the forest, but I’ve seen some windstorms in the desert where no tarp could stand up to it no matter what I did.
      Bob

  3. HOTROD says:

    Bob,
    I would like to suggest the use of a homemade swamp cooler. its a garbage can and a small water pump. Fan blows the cooler air in to the van. It Runs off a battery. Plans for the cooler are on the internet.
    Never used one but it might be useful. I plan to use such a device when my turn comes. On a side note I plan on buying land in south
    Texas (terlingua). Land is cheap desert with no building codes. Search for “John wells off grid Terlingua tx” and you see how he does it.

    May God bless us all.

    • Bob Bob says:

      Thanks Hotrod, that’s a very good idea. Swamp coolers do work, but only in dry environments. As a snowbird I just move to where it is cooler so passive cooling has been all I need. If I ever need to I would definitely try a swamp cooler.
      Bob

    • WTXCal says:

      Hi Hotrod,
      I live in Alpine, about 100 miles north of Terlingua and a much higher elevation 4500′. It’s common for summertime temps in Terlingua to be 110-120. Good luck. WTXCal

  4. Scott says:

    Have you tried a swamp cooler?

  5. Teri Live Oak, Fl says:

    Very informative post. Do you have problems with insects? Thanks

    • Bob Bob says:

      Teri, not usually but sometimes. I have screens for both front windows so that helps a lot but not being able to open the side door really hurts. I’ll put on fan on the front seat to pull more air through and one fan in back to hit me. So far that’s all I’ve needed.
      Bob

  6. These are great tips, thank you. Last winter I was in Florida, so it was pretty easy to find shade. I guess things will be different for me this winter in the southwest!
    Jim Schmechel recently posted…Ruegsegger FarmsMy Profile

    • Bob Bob says:

      Jim, there are some places in the desert where you can find shade, but for the most part there’s none! But the desert can be surprisingly cold, come ready for both, heat and cold. It’s also an El Nino year so it could easily be cooler and wetter than normal.
      Bob

  7. “…you want to try to park the van so…heat can escape through the side door.”

    Or, open a back door too and position the van so that the breeze can flow through.
    Al Christensen recently posted…Can you smell the trout?My Profile

    • judy says:

      I’m parked in my daughter’s driveway within feet of a 4 way stop intersection. The van side doors (north) and rear doors (east) face streets & the neighbors. I open both side doors into a shallow V resting the doors against one another and then wedge open one rear door a couple inches to take advantage of the breeze.

      Every morning before sunup I try to get the cooler air into the van, closing things on the sunny side once the sun hits.

      I have the windshield cover Bob describes (love it!!). The magnet near the door handles can be flipped up to the roof. This will make a partly shaded yet half open window. I can sit on the platform between the seats facing rearward to catch a breeze blowing through the front windows.
      On rainy days I can have the front windows open & bow out the window cover a bit with a walking stick. Just need to check for windblown rain occasionally.

      The reflectix I had used on the inside of the windshield I now use on the outside of my rear door windows. A clip on each top corner attaches it to the gutter. My rear windows open out from the bottom so I clip the lower corners to my windows.

      When it is esp. sunny & hot, I kept the heat off the south side windows of my van by clipping 3 throw rugs to the gutter. If you keep the windows from heating up, there is less heat to radiate to the inside.

      My biggest worry about spending my summer in OH & near Boston was the heat…I have managed much better than I anticipated.

      There have been surprisingly few bugs here in MA this summer. A couple mosquitoes one night.

    • Bob Bob says:

      Very good point Al!
      Bob

  8. Bill says:

    I have seen small swamp coolers in travel trailers in Az but they were pretty much set up permanently in the desert area around Quartzsite. I took a class in natural green living. The instructor pointed out why the old southern homes were built under huge trees. Notice I did not say huge trees were allowed to grow. Anyway we all know that it’s cooler in the shade but it’s also much cooler than just the shade. A tree respirator water vapor out thru it’s leaves and to put it simply it’s nature’s own swamp cooler!

    Bill n Sadie plus Mic
    Bill recently posted…Its Mic, The Hangin Tree StockdogMy Profile

  9. Alan says:

    I learned a great deal from Bob’s previously posted advice on passive solar and integrated his ideas into my current conversion project.

    I covered my roof with solar panels mounted to a roof rack, which create shade as well as electricity. For active cooling, I have two vents with fan-tastic fans, with the idea that I can use one to pull in air and one to blow out air. The covers also create shade. And where the solar panels and vent covers don’t shade – the gaps – I’m putting in painted wood pieces and a wind fairing. (In the photo linked at bottom, you can barely see one wood piece already installed and a marker for where the other piece and the wind fairing will go.)

    I installed a left-side Foxwing awning. The idea is that when possible I can park the van facing north and have shaded west and south sides. The Foxwing has optional sidewalls I can purchase and zip on for more shade and rain protection. I also may put a rectangular awning on the right side of the van at some point for east side shade.

    Of course, I got a white van in part for its reflective color.

    I really like the ADCO windshield cover. May have to get one at some point!

    Here’s a photo of the roof rack and awning: https://drive.google.com/file/d/0ByVtkOWOKq_JdFA4VTdXZ1VpM2s/view?usp=sharing

  10. Bob G says:

    I was browsing Austin Craigslist today and saw something that would be right up your alley, or maybe one of your readers’. Nice looking and not very expensive, either.

    http://austin.craigslist.org/rvs/5097400086.html

    • Bob Bob says:

      Bob, that is very nice! I sent him an email and asked if I could turn it into a blog post, I’ll have to see if he is willing.

      Thanks for letting me know about it!
      Bob

  11. Carla says:

    I have a very high (9’5″ overall van height) fiberglass high-top on my van as it used to be a wheel-chair-lift public transit van. I have been advised NOT to attach anything to that roof (to not make holes in it). I am really jealous of roof gutters and roof racks and all that sort of thing! My van has an escape hatch in the roof. However, the van is a 97 and had 177,000 miles on it when I bought it. I have been afraid that if I ever open that hatch, it will break whatever seal it has and I might begin to leak. (I have a few leaks in places where the roof meets the walls when rain is heavy and cannot get them to stay sealed.) Last year when I traveled so much, I did what Bob does — headed to cooler elevations (Montana) in June and stayed until cold days chased me back south.
    Carla recently posted…Baking Soda & Vinegar for Hair — Why?My Profile

  12. tommy helms says:

    There are also cooling vests you can buy on Amazon.com. Construction workers use them in the summertime. You soak them in cool water for a minute, and as the water evaporates the vest will keep you cool for 3-5 hours. They are between 30-50 dollars.

  13. Ming says:

    thanks Bob and everyone for loads of great tips!

  14. Joe Lawson says:

    Hi Bob,

    Thanks so much for this useful information.

    I am hoping to full-time in a Prius. I’d like to be able to cover it and an adjacent campsite with a tarp or easy up along with bug netting. Since the Prius is so low, I’m hoping I could drive it right underneath. I’d like to be able to stand up and walk around throughout the entire area while being protected from bugs, rain and sun. Do you have any ideas how this could be accomplished?

    • Bob Bob says:

      Joe, it depends on what you mean by ” I’d like to be able to stand up and walk around throughout the entire area” how big an area do you want? You could set up a 12×12 Easy Up and be protected from the rain. Some of them let you add screens and even walls. I’d suggest a combination of a Awning for rain protection and a screen room for bug protection.
      Bob

      • Joe Lawson says:

        I looked into the Easy Up. That would be a very good solution except for one thing. Their structure causes them to be bulky when packed away. Uses too much space inside a Prius.

        I would like to cover the entire car with room to walk around it. It is 15 feet long. I could set up my camp right next to the car. So I’d like an area 15′ x 20′. Since the car is so low, connecting an awning to it wouldn’t be practical. I wouldn’t be able to stand up. Unless perhaps I had a roof rack with some vertical extensions to get extra height.

        • Bob Bob says:

          Joe, this isn’t what you want to hear, but living in a Prius simply doesn’t allow you many luxuries, and what you want falls in that category.

          Here is a compromise; get light shade cloth wide enough to drape over the whole Prius. Get 2 kids swimming noodles the length of the roof. Put the noodels on the top of the roof running with the car. Drape the shade cloth/netting over it. Stake it down away from the car on one side. The side you use most use walking sticks fully extended as poles and tie them down support the cloth. Carry a silver tarp to use for rain instead of heat. The noodles hold the tarp/netting off so there is air circulation under them.

          It’s not what you want, but it is doable.
          Bob

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