Importance of campervan insulation
If you’re serious about taking your van on the road, you need to make sure you have proper insulation. Good insulation will help slow the rate of heat transfer into and out of the van. That means, reacting to the temperature outside, your van will stay cooler in summer and warmer in winter. It also means, it will but it will also make it easier to heat and cool your space when you need to. And it will stay hotter and cooler in all the ways you want it to.
Good insulation might just save you from freezing your buns off in the winter and sweating like a sinner in summer.
So, remember, when it comes to campervan insulation, insulation is like your winter coat; you want it to be warm and effective, functional to the required temperatures, a good fit, and affordable.
Plus, we’ll learn that proper insulation can help protect your van from water damage and keep the environment inside healthy.
If I’m not convincing you that it makes a difference, trust me, it really does. It’s hard to describe how horrendous a heatwave in a van can be, or how horrible trying to sleep when it’s lower than 2 degrees outside is. Insulation helps with both. And if you think you don’t need it because you are only going where it’s a pleasant 25 degrees all the time, think again. On our travels through Eastern Europe, one day it was 30 degrees on the coast of Montenegro, then next, up in the mountains (a mere 1.5 hours drive away) it dropped to close to zero.
We were very glad for the insulation.
We’re convinced we need insulation, and want to get it right. This article will act as our primer, we’ll look at some of the theory of heat transfer in a van to set us up for deciding on the kind of insulation that is required. ( you can jump to insulation materials here)
Some convert a van science
Most people don’t know it’s called this, but one of the main concerns for campervan owners is heat transfer. It’s the thing that gets people moaning about being too hot or too cold. Heat Transfer occurs in three ways, through radiation, conduction, and convection. We’ll go through each and give you tips on how to manage them as we go.
Radiation
Radiation heat transfer occurs when there is no contact between the heat source and heated object. In a campervan, one of the main sources of radiant heat is windows. Sunlight passing through windows can heat up the inside of the van, making it uncomfortable to be in. However, in the winter, the sun’s rays can be beneficial, providing natural warmth and light. To reduce the amount of radiant heat entering the van, you can install reflective window coverings or curtains. These coverings reflect the sun’s rays, reducing the amount of heat that enters the van. Using lighter-colored materials for your curtains or window coverings can also help reduce radiant heat gain.
Conduction:
Heat transfer occurs through conduction between two solid bodies. In a campervan, the metal body of a van can warm up from the sun through conduction. The walls, ceiling, and floor of a van can all act as a medium for heat transfer through conduction. Installing insulation in the walls, floor, and ceiling of the van can slow down the heat transfer through conduction. Insulation works by trapping air in between the fibers, which is a poor conductor of heat. The thicker the insulation, the slower the heat transfer through conduction.
Convection:
Heat transfer through convection occurs when heat moves through a gas or liquid by the hotter material moving into a cooler area. Heat inside a van naturally rises upwards, creating convection currents that can draw heat out of the van. The ceiling of a van is the largest surface area and can be a major source of heat loss through convection. Installing thicker insulation in the roof can slow down heat loss through convection. You can also use a ventilation fan to suck out the warmer air near the ceiling while pulling in cooler air from a floor vent or cracked window. By eliminating air gaps and insulating hollow structures in the van, you can reduce heat loss through convection.
By addressing heat transfer through radiation, conduction, and convection, you can make your campervan more comfortable in any weather.
Thermal Bridging
Let’s talk about thermal bridging – the sneaky way heat can escape from your campervan. Basically, thermal bridges are like little shortcuts for heat to pass through, and they’re often found in metal parts. So, if you’ve got any exposed metal in your van, it could be acting like a secret passage for your heat to escape!
But don’t worry, you can fight back against thermal bridging. One way to do this is by insulating the hollow frame of your van. This will make it harder for heat to escape through those metal parts. Another option is to add something called a “thermal break”, which is like a shield that blocks the flow of heat. You can use special materials like LOW-E to create these thermal breaks.
And if you really want to take things to the next level, you can add more insulation on top of your van’s ribs. This will create an extra barrier against heat loss, so you can keep the inside of your van nice and toasty.
Insulation
For the main event, insulation and the qualities we want to look out for.
R Value
When it comes to insulating your campervan, you want to make sure you’re not wasting energy and money. That’s where R-value comes in, which measures the material’s ability to resist heat flow.
R-value is determined through a fancy test called the ASTM C518, which looks at how well a material (i.e. our insulation) resists heat through a given thickness. This test takes into account all three ways that heat can transfer: conduction, convection, and radiation.
When looking at campervan insulation a higher R-value per inch indicates greater insulating power, meaning a material with a higher R-value will insulate better than a material with a lower R-value.
The higher the R-value, the better the insulation will be at keeping the warmth inside and the cold outside.
This makes it an important metric to look at when choosing your campervan insulation.
But R-value is just one piece of the puzzle when it comes to campervan insulation. You also need to consider factors like your budget, ease of installation, moisture resistance, and flexibility.
R-values are actually calculated as R = l/λ, where l is the thickness of the material in meters and λ is the thermal conductivity of the material in W/m.K.
So, when selecting insulation for a campervan, it’s crucial to consider not only the R-value but also the thickness of the insulation to achieve optimal thermal resistance.
Moisture
Keeping the inside of your campervan dry and comfortable is important for a pleasant journey.
One factor to consider is condensation and moisture control. [We have a whole guide on this here.] To prevent moist air from migrating towards cold surfaces, vapor barriers are used, but they can’t keep all moisture out.
In fact, campervans aren’t made to keep the water out at all.
If you take off the door panel of your van, I’m betting you’ll find plastic sheets directing water flow to tiny holes at the bottom of the panels. These holes are there because everything, from the door handles to the hinges, leaks! Most campervans have moldings on the roof that are clipped on using plastic clips, which, unfortunately, also leak. Plastic, along with sprayed wax on inner walls are proof of the confidence van manufacturers have that water will get inside.
And that’s just from the outside in. Don’t forget about the condensation caused by us, from the inside out. Here’s our breakdown of condensation, if you’re interested.
So, always expect water to be present within the walls.
Insulation layers should therefore allow the campervan to “breathe,” allowing moist air to escape, and not get saturated and stay wet, causing rust from the inside out and all sorts of things you definitely do not want.
So what do we now know?
Heat moves around our campervans in three ways, Radiation, Conduction and Convection.
Thermal bridges are areas where heat can transfer quickly, and need to be addressed in the insulation process.
Heat loss will occur through open space, through metal and glass. That’s the floor, ceiling, doors, windows, walls, ribs, vents and empty spaces. For minimum heat transfer, we need to consider how we insulate all of these areas.
When choosing our insulation type, we need to check it’s R Value. The higher the R Value the better the insulation.
We know that vans get wet inside, so good insulation also needs to be breathable.
On top of that, we have our guiding principles of van build:
- Keep costs as low as possible
- Be environmentally friendly
- 80/20
- Do a proper job
Now let’s look at the insulation available on the market.