Insulation is a big topic in the nomad life, and an important part of keeping warm and keeping cool! When you live in a vehicle, depending on where and how you use it, you may wish to insulate your vehicle. There is no clear solid consensus on what the "best" way to insulate a van is, but there sure are a lot of opinions with very little in the way of empirical data. At best, you're making an educated guess and almost everyone insulates their van differently.
FarOutRide's guide is a good place to start. Also look at Lenny's blog article on thermodynamics.
First, a terminology note:
- Insulation — a material which reduces the rate of heat transfer between two places, the subject of this page.
- Insolation — the amount of sunlight a solar panel receives.
Both terms are used in van life, but insulation is discussed far more often.
Goals of insulation
Insulation can help retain heat in cold weather, and reduce transfer from hot body panels in direct sunlight in warmer weather. Insulation will not, by itself, make your van cooler than ambient in the summer or warmer than ambient in the winter. But it will help when aided with either heating or ventilation to keep the interior more livable.
Uninsulated vehicles
Some nomads choose to live in completely uninsulated vehicles to save money, save space, and reduce the complexity of their build. For those who need or want to go the removable build route, forgoing insulation altogether may be a requirement. So how does the uninsulated option work? If you are willing and able to follow good weather, it's possible to skip insulation altogether. Continue reading …
Tips and tricks
It is better to insulate the entire van poorly than to only insulate part of the van well.
Windows are going to be the largest source of both heat loss or heat gain by far. Especially If you have a van with windows all around, it's pointless to do any insulation to the body at all if you're not doing something about the windows in the form of insulated or reflective window coverings. Again, exactly what type of window covering you have isn't as important as just having SOME sort of window covering.
Similarly, the sheet metal of the van makes an incredibly effective thermal bridge. You can go crazy with stuffing Thinsulate into every single nook and cranny, but even just a few strips of exposed body sheet metal to the interior will almost completely negate all of that work. To effectively insulate your van, everything needs to be covered. Even a thin covering of carpet spray-glued to exposed sheet metal will make a world of difference.
4-Way stretch carpet is ideal for this. Because it has some give to it, it's possible to mold it over and around all the sort of crazy compound curves that makes up the van body. Many videos on YouTube showing this process, here or here.
Open-Cell vs Closed-Cell insulation
https://www.secondskinaudio.com/heat-insulation/open-cell-foam-vs-closed-cell-foam/
Ceramic paint additives
Ceramic paint additives are special ceramic powders that can be stirred into any paint. This paint is then applied to the vehicle, which helps reduce heat transfer between the interior and exterior. It effectively makes a very thin radiant heat barrier, which helps keep your vehicle interior cooler in the summer (especially while in direct sunlight) and warmer in the winter. More …
The effect of "Total" R-Value
Total R-Value is the total R-Value of a given construction, taking into account all the different R-values of the different sections that it might have. For example, a well-constructed residential wall in a house in a cold climate might have an R-Value of 20[1] (1/2" plywood, then 1" of Poly-Sty, then a vapor barrier, 3.5" of fiberglass batting with wood studs forming the wall, then 1/2" drywall), while a solid-core door might have an R-Value of 4 and triple-pane windows might have an R-Value of 2.5-3[2].
A basic van insulation build for the walls will have an R-Value of ~R-5, with some sheet insulation like 400 Thinsulate, some mini-cell foam for the floor and a basic liner to cover up all of the ribs and make sure we don't have any exposed metal. A better-insulated build for cold weather use might have an R-Value as high as R-8 to R-10, filling every single nook and cranny with 600 Thinsulate, mini-cell foam and poly-sty sheet for the floors, maybe poly-sty for the walls as well covered with plywood or wood slats or even 4-way stretch carpet.
Single-pane windows (such as most automotive window glass) have an R-Value of about 0.91.
Let's look at some examples of how this dramatic heat loss from windows affects the total insulation of your van using this total R-Value calculator.
Let's say we're insulating a van with windows all around, like a former passenger van/shuttle bus. In this case, about 35% of the van's surface area is going to be glass.
We'll start with a typical kinda basic insulation, like what you'd get from the factory or most people who are doing a full build out of their own and not going too crazy. An R-Value of 5 for the walls, and 1 for the windows.
Huh! So in spite of all that insulation work, you got an R-Value of barely over 2. You're very chilly at night, so let's say you DO go crazy with the insulation! You spend a thousand bucks on 600 thickness thinsulite, you stuff it in EVERY nook and cranny, you put mini-cell foam pads on all the sheet metal and then cover the whole inside of the van with some sheet poly-sty and then a solid sheet of plywood or wood paneling. You've gotten the R-Value up to 10 (Which is REALLY REALLY hard). Let's try it again:
Wait so you DOUBLED the insulation on the walls, and it barely made a dent in your total R-Value! Damn. Well, let's go REALLY nuts! Let's build it like we do a house, and do a full wood frame inside with an inch of poly-sty, wood studs spacing out 3.5" of fiberglass batt, plus a vapor barrier and 1/2" of plywood. That can get us up to an R-Value of 20 for the walls (This would lose you a HUGE amount of space inside, but let's just do it as an experiment):
WUT?! You went bat-shit nuts and lost a ton of interior space, and your van is still leaking heat like a sieve because of the massive loss through those windows.
BUT. Let's assume we do a bit of insulation on the windows. Nothing crazy, just add some window covers DIYed out of scrap material. Some thick cardboard, wrapped in some $5 fleece blankets that you got from Walmart and tightly fit into the window openings to covering them completely is a great start. This will get the window R-value up to around 3 if you leave a bit of an air gap. Let's see how that changes our calculations, even with our basic lazy van insulation:
WILL YOU LOOK AT THAT! Just by covering the windows, poorly, and insulating the rest of the van to a kinda-mediocre level, you've got NEARLY TWICE the total system insulation as if you did a completely nutso, bonkers, over-the-top insulation job but haven't covered the windows!
TL;DR - COVER YOUR DANG WINDOWS IF YOU'RE TRYING TO STAY WARM
Speaking of...
Windows
Many companies make window coverings for vans, some are available with Reflective coating to help keep the sun out. Others are thickly insulated to help keep heat in. Prices and quality range from very minimal, to very expensive. Plenty of people DIY these as well.
Van Essentials has a pretty good comparison chart of costs (biased as it may be).
Some other sources:
- https://vanmadegear.com/
- https://diyadventurevanco.com/
- https://www.stelletek.com/store
- https://strawfoothandmade.com/
- https://thisvanlife.net/collections/all
- http://www.xplroutfitters.com/index.html
- https://www.vanessential.com/
- https://vanupgrades.com/
- https://www.heatshieldstore.com/
- https://www.high-end-motorsports.com/ - Good inexpensive sun shades
Floors
Insulating the floor is done not only for thermal comfort, but for sound while driving. A bare metal cargo van receives a shocking amount of road noise, and the large slabs of metal act like a drum to amplify it.
For extremely simple builds, throwing some basic rubber mats over the floor (and cutting to fit, possibly attaching down with spray-glue) will make a world of difference over just a plain metal floor. Anti-Fatigue mats can be very cheap and are easy to cut to fit whatever space you happen to have.
Rigid-core foam board under plywood works well for thermal insulation, but can lead to more vibration and squeaks as the van moves while driving. Mini-cell foam is a popular sub-floor insulation that gives both reasonable thermal as well as acoustic insulation.
Heat from solar panels
Even if you're sticking to mild climates and have a van with a ton of windows, there is something to be gained from doing some kind of insulation on at least the roof underneath the solar panels. Heat re-radiated from the underside of the panels may increase roof temperatures even though the roof is shaded by the panels.[3]
If you don't have panels, the heat from the sun can easily make the interior sheet metal burning hot to the touch. Covering it with some insulation (and ventilating the van well) will help keep things more tolerable.
Vapor barriers
Resources
| Resource | Description | |
|---|---|---|
| Floor insulation impact | Is it worth insulating your vehicle's floor? | |
| Heat loss calculator | Various materials transfer heat at various speeds. You can use this heat loss calculator to estimate your heat losses. | |
| Insulating thermal bridges | Solution to insulate thermal bridges from metal beams in a van. | |
| Insulation Testing | Tests performance of three different campervan insulation options: Polyiso, Thinsulate, and Wool. | |
| Insulation installation guide | How to install various types of insulation effectively. | |
| Insulation installing guide | How to install various types of insulation effectively. | |
| Thermal bridge testing | Testing thermal bridges in a campervan | |
| Ceiling vs Floor Heat Loss | Test the differences in heat loss between a van floor and ceiling. | |
| Difference between rigid foam boards | Learn the difference between Polyisocyanurate (PIR), Extruded Polystyrene (XPS), Expanded Polystyrene (EPS) and Styrofoam boards. | |
| R-Value Calculator | Find your effective R-value (or U-value) by adding the surface areas of every material and specifying individual R-values. | |
| Testing water absorption of insulation | How much water do various types of insulation absorb when immersed in water? | |
| Reflectix® | Official site of Reflectix brand reflective bubble insulation | |
| HVAC and insulation forum | A sub-forum of VanLivingForum.com | |
| Search forums and groups | Search van life discussion groups for "insulation" | |
| Search related sites | Search van life sites for "insulation" | |
| Search NomadLife.wiki | Search other pages on this wiki for "insulation" |
Some or all of the content on this page was originally sourced from this page on RVWiki