The essential guide to camper van insulation and ventilation

Your camper van insulation and ventilation is integral to the comfort level of your van life. A well ventilated van will help remove hot air, cooking smells and water vapour so will smell fresh. A well insulated van will be warm and cosy in the cold and cool in the heat. Insulation and ventilation work hand in hand so consider both before you start your installation. This post will guide you through all you need to know and camper van insulation and ventilation to help you in your own conversion.

Why is ventilation in your camper van important?

Condensation is a camper van’s enemy because it leads to rust. Cooking, wet areas and even people breathing in the camper van create water vapour. With so many potential sources, an effective ventiliation system will prevent a huge problem.

If there isn’t enough air flow in a camper van, condensation will build up and cause damp, mould and rust. Avoid condensation by improving airflow with a good all round ventilation system.

How much ventilation does your camper van need?

How much ventilation a camper van needs depends on a few factors so there’s no hard and fast rule. Yet the fundamental principles of ventilation remain the same. A good ventilation system means bringing in air from outside and creating circulation.

A camper van needs enough ventilation to keep air circulating and to remove hot air, water vapour and pollutants. The more people using the camper van, the greater the ventilation system needed.

Because cold air sinks, hot air gathers at the ceiling of the camper. So roof vents are perfect to expel air from the camper van. Place vents to bring fresh air in lower down on the camper van walls or floor.

What type of ventilation is best for my camper van?

The most basic type of ventilation for a camper van is to open the doors and windows. It’s a low cost but incomplete approach. During the winter months, it’s not practical to keep your windows and doors open and it leaves you without any security. So what options do you have to ventilate your camper van?

Wind deflectors for your windows

You can gain a little security by installing wind deflectors to the side windows so you can leave them open a little at night. Every bit of fresh air intake counts when it comes to ventilating a camper van.

Louvred air vents

A few louvred air vents fitted in strategic positions in the walls of your camper van will give a constant fresh air intake. You’ll need to cut holes in the side of the van where you want to fit the vents but the products are low cost. Make sure you fit fly screens behind each vent to stop unwanted bugs entering your camper van.

Wind powered roof vent

These wind powered roof vents are small so ideal for ribbed roofs such as those on a Sprinter van. Powered only by the wind, these vents won’t drain your batteries and pick up quite a speed whilst driving. The extraction rates can get quite high so they’re more effective than the louvred air vents.

Pop top roof vents

Our Unimog, Mowgli had 4 of these pop up roof vents. They open on all 4 sides so can provide constant ventilation and they had fly screens already fitted. We used to drive with them open so we know they’re strong and robust. Again, you’ll need to cut holes in the camper van to fit these vents.

Extractor vents

Our Sprinter van conversion has a had one of these extractor vents installed. Fitted with a 12v motor the fan can rotate in either direction so air is either expelled or drawn. Because our Sprinter van Baloo was a minibus in a previous life, we bought her with an extractor fan already fitted. Baloo has loads of ventilation now. We’ll keep you posted on how it all performs.

Chances are you’ll use one or two of these together in your camper van ventilation design. The important thing is to have enough movement of air into and out of the camper van to get rid of any lingering water vapour.


Essential reading: how to plan your camper van conversion

Why is insulation in your camper van important?

Base vehicles, ripe for conversion, tend to have little or no insulation installed. It may have started life as a courier van or something of the like. It never needed to be warm and cosy because it was never intended as a home. Now we want to turn our van into a comfortable camper van. So how do we turn a metal shell into a home to keep us warm in the cold and cool in the heat? Decent insulation combined with good ventilation, we create an environment anyone would be proud to call home.


Also read: choosing a base vehicle for your camper van conversion

How much insulation does your camper van need?

How much insulation you need depends on where you intend to take it. You’ll need better thermal performance if you want to live in your van during cold winter months. The primary aim of insulating your camper van is to reduce heat loss in cold weather and to keep the inside cool when it’s hot outside.

What type of insulation is best for my camper van?

A nightmare of a question! You only have to google it and you’ll find a multitude of answers, everyone with an opinion on what is right and wrong and yet all inconsistent. It drove us mad when we started to research how we would insulate Baloo.  So here we’re not going to even try to tell you what’s right or wrong. Instead, here’s a list of the materials you can use to insulate your camper conversion. When deciding what combination of materials to use in your own conversion, consider your ventilation at the same time. Avoiding and managing condensation is critical in maintaining a pleasant home.

Reflectix foil wrap

This material is like silver bubble wrap. Because it’s a radiant barrier, Reflectix is often used as sun shade on the inside of camper van windows. There’s a lot of debate on how effective this stuff is as an insulator on the camper van walls though. It is most effective with an air gap so this needs to consideration before adding the next layer of insulation.

The inside of most camper van walls consist of large flat(ish) panels and lots of smaller spaces too. Reflectix is easy enough to install on the larger panel areas with adhesive tape or spray.

Rigid Panels

Polystyrene and styrofoam boards are low cost and quick and easy to fit to the large panel in the camper van. We used 25mm on the roof of our Sprinter van conversion and and 40mm thick board in the walls. In Mowgli our Unimog camper, we had 40mm boards all round. We used the boards that are foil lined on both sides as it gives a slight improvement on the thermal protection.

Loft insulation

This is the flexible rolls of material we find in many lofts. The advantage of loft insulation is you can squeeze it into all the nooks and crannies you can’t fit the boards into. Again, the choice of materials is wide. You can choose fibreglass, recycled plastic, recycled denim or wool. They all have different properties and R-value. Wool tends to have the highest R-value (thermal protection). Fibreglass is nasty stuff to work with because it makes you itch and you need to wear a mask and gloves to install it. It doesn’t handle moisture too well either. We used the recycled plastic bottle material in our Sprinter van conversion.

Vapour barrier

Many camper conversions add a vapour barrier over the top of the insulation and before lining the walls and ceiling. This will prevent any water vapour not ventilated making it’s way to the metal and eroding it over time.

Many converted camper vans use a combination of insulation materials. In our Sprinter van Baloo, we’ve used rigid panels with recycled plastic bottle loft insulation. We have refitted the original headliner and it is also insulated with wool and a vapour barrier too. We’ve not used a vapour barrier on the walls.


Your camper van insulation and ventilation work together to help provide a clean, warm and dry home. Because you’ll only install the insulation once, our advice is to do it well. Have plenty of ventilation and the structure of your camper van will give you many, many comfortable van life years.

Do you want to show your support or say thanks for our free guides? Give us a like on Facebook or sign up for our free newsletter!

Like it? Pin it!

The essential guide to Camper van insulation and ventilation. Read the full article here: http://mowgli-adventures.com/camper-van-insulation-and-ventilation/


Disclosure: Some of the links in this post are affiliate links. This means if you click on the link and make a purchase, we will receive an affiliate commission. But don’t worry, it doesn’t cost you any extra.

Are you building your own camper van? Check out our camper van conversion guides here.