Why is campervan ventilation an important subject?
When it comes to owning a campervan, ensuring proper ventilation is crucial to maintaining a comfortable and healthy living environment. As we’ve learned, campervans are notorious for condensation and one of the key ways we can fix condensation problems is by ventilating the space.
Excessive humidity caused by activities such as cooking, showering, and breathing can promote the growth of mould, fungus, and dust mites, which is nasty for anyone but can be particularly hazardous for people with allergies and asthma.
But proper ventilation isn’t just about keeping the air fresh and clean. It can also help regulate the internal climate of your campervan, preventing hot air from building up and making the space uncomfortably hot and stuffy.
In addition, a well-designed ventilation system can combat unpleasant odours and pollutants that can accumulate over time, particularly in hot climates where human sweat can exacerbate the problem.
One of the most common problems associated with poor ventilation in campervans is condensation. When warm, moist air collides with colder surfaces, such as uninsulated windows and exposed metal surfaces, it converts to liquid and causes condensation. This can lead to dampness and mould growth, which can be especially harmful to your health and your campervan.
By installing an efficient ventilation system in the right locations around your campervan, you can combat these issues and maintain a fresh and comfortable living environment. In this article we will discuss the causes of condensation, where it typically forms in a campervan, its effects on the van and your health, and ways to mitigate all of this with ventilation. We’ll wrap up with how to install the roof vents of your choice.
A quick review on what causes condensation in my campervan?
We have an entire article dedicated to condensation in a campervan, but let’s give you the 101 here:
Condensation can be caused by a number of factors, but the primary cause is warm, humid air coming into contact with a colder surface. This moisture in the air is deposited on the surface, leading to condensation. In a campervan, the most common causes of condensation include:
Breathing: Every time you exhale, you release water vapour into the air. When you’re inside a campervan, this moisture can build up and contribute to condensation. In fact, we contribute something like 200ml of water per hour, just from exhaling.
Cooking: Any cooking process that involves boiling water or steam will release moisture into the air, contributing to increased humidity levels in the campervan.
Personal hygiene: Taking a hot shower or washing dishes with hot water will contribute to increased humidity levels.
Gas: If you’re using a natural/ LPG gas stove, it produces water vapour as a byproduct of combustion. This can increase the moisture in the air and contribute to condensation.
What happens if I have condensation over a long period?
Condensation typically occurs on uninsulated, heat-conductive surfaces like windows, metal panels, and furniture in the campervan.
If you have condensation in your campervan for a prolonged period, you may be in for some potentially serious problems.
Firstly, the moisture from the condensation can provide the perfect environment for fungi and bacteria to grow. This can lead, first, to a build-up of unpleasant odours and, second, to potentially harmful spores that can cause respiratory problems for some people.
Another issue with condensation is that it can cause damage to your campervan’s structure and interior surfaces. Over time, the moisture can lead to rust formation on exposed metal, and damage to wood or fabrics.
Ventilation: Passive and active
Proper ventilation is crucial to maintaining a comfortable and healthy living environment inside your campervan. There are two main types of ventilation: passive and active. Each type has its advantages and disadvantages, and choosing the right one for your campervan depends on a variety of factors.
Passive ventilation
Passive ventilation is a natural and eco-friendly option that relies on natural air currents and the buoyancy of heat to circulate air in the campervan. This type of ventilation doesn’t require any power, making it a low-maintenance and affordable option. Passive ventilation loses efficiency in higher temperatures and in lower temperatures, it can let in too much cold (drafts in windy environments).
Examples of passive ventilation include:
- Roof vents: Installing roof vents is an excellent way to allow air to circulate and escape hot, moist air from your campervan.
- Side vents: Installing side vents can improve airflow and circulation in your camper.
- Windows: Installing windows can improve air circulation, let natural light in, and provide additional ventilation.
- Insulation: Proper insulation of your van’s interior can help maintain a comfortable temperature inside and prevent condensation.
Active Ventilation
Active ventilation, on the other hand, uses power-driven fans to circulate air in the campervan. This type of ventilation is more effective at expelling hot, moist air from the campervan and can be used regardless of weather conditions.
However, it’s costlier and requires maintenance of wires and moving parts. It really comes into its own if you need to cool down but can’t have your windows open, because for example, you’re surrounded by mosquitoes.
Examples of active ventilation include:
- Powered fans: Installing powered fans can help circulate fresh air throughout your campervan. These fans can be operated manually or through a thermostat.
- Air conditioning: Air conditioning is a highly effective way to regulate the temperature and humidity inside your campervan, but it’s also the most expensive option.
Ventilation considerations
Ventilation is crucial in a campervan, and there are several factors to consider to create an effective system. One important consideration is ventilation positioning. To create a circulatory system, one ventilation point should be placed low down in the camper to draw in cool, fresh air, and the other should be higher up to provide an escape for hot, stale air. This system works best with paired vents.
Another factor to consider is the surrounding environment. In hot climates, more ventilation is necessary to keep the camper cool and fresh, while in colder places, ventilation is required to combat condensation and humidity caused by the temperature difference between outside and inside the camper. Cooking inside or having an onboard shower also requires good ventilation to reduce heat, cooking smells, and gas build-up.
M3/hour, or volume flow rate of ventilated air for fan-assisted ventilation solutions, is another factor to consider. A higher m3/hour rate means quicker and more effective air circulation, but it doesn’t necessarily mean a better ventilation solution. The ventilation solution should match the camper’s size and the required ventilation needs.
So, for a fresh camper with an interior that isn’t going to smell or kill you, and an exterior that won’t rust from the inside out, proper ventilation is crucial.
The two types of ventilation are active and passive: passive ventilation is eco-friendly, more affordable, and low maintenance, but it’s less effective in warmer climates. Active ventilation, powered by electricity, is more effective at expelling hot, moist air from your camper, but it’s costlier and requires maintenance.
To create an effective ventilation system, you’re probably going to need a bit of both, and will need to think about the positioning of the ventilation points and the surrounding environment.
Ways to ventilate
Opening a window
If you’re looking for a simple way to ventilate your campervan, opening a window is your answer. It’s the most effortless and straightforward way to get fresh air into your vehicle – just roll down the window, and you have an instant ventilation system. But before you decide to leave your window(s) open, there are a few things you need to consider.
On the upside, there’s no need to physically alter your vehicle to use this method, and it’s quick and easy and requires no extra investment. That being said, leaving the window(s) open can risk potential break-ins and bring the weather inside, not to mention little biting bugs. Plus, if you only open the window a few inches, it won’t provide enough ventilation to recirculate a large volume of fresh air around your vehicle, so we’re going to need to add additional opening windows for a more effective circulatory system.
Wind deflectors
Using wind deflectors is a step up from just opening your windows, and can provide you with more opportunity for passive ventilation for your campervan.
Installing wind deflectors on your campervan windows is a cheap solution if you want to leave your windows slightly open without attracting unwanted attention. These deflectors do a great job of disguising the fact that your windows are open, making it less likely for prying eyes to notice, and there is no need for any real vehicle adaptations.
You just clip them on, usually. Plus, they should keep the rain out.
Au contraire, wind deflectors rely on manual airflow, so there’s a limit to the ventilation they will provide. And you want to consider security. While they can help to disguise an open window from potential intruders, they don’t completely secure your van, and it would be easy to break in should anyone notice. Which means, you shouldn’t leave your van unattended. Sleeping is probably ok.
Louvre air vents
Fitting louvred air vents to your van walls is a practical way of creating a purpose-built ventilation system. This method will mean you’ll have to cut holes in the side of your campervan where you want to fit the vents. Louvre vents work most effectively if installed as a pair or opposite another type of vent to keep air moving by creating a circulatory system.
There are advantages to using louvred air vents. They are inexpensive and simple to install, and some models feature a manual open/close vent system, making them relatively secure.
However, you will need to cut holes in vans, which is always daunting, and once in, they can really make a van look like a campervan, which sometimes goes against our desired aesthetic, and if it’s especially cold or windy, then the can create a cold draught in your camper.
Rotary roof vent
A wind-powered rotary roof vent is a highly effective ventilation system that can be powered by the wind. It offers better ventilation than louvred air vents, with a high extraction rate. These vents sit on the roof (good for stealth campers) and are simple to install, fully waterproof, and secure. Some models even feature a manual open/close vent system; nice.
There are a few disadvantages to keep in mind. If not properly maintained, the internal bearing of the rotary roof vent may become defective. And, falling under the passive ventilation umbrella, they rely on manual airflow.
Roof opening vent
A roof opening vent is a skylight in the roof that opens, usually on a few different levels from cracked to fully open. Aside from ventilation, it also allows natural light to enter the vehicle, making the interior brighter.
A roof vent or two would be considered adequate for most campervan builds.
The benefits are many: They are fairly cost effective, are pretty secure and lots of models come with built-in fly-screen that can keep insects and bugs out while still allowing fresh air to flow through. Because they are on the roof and hot air naturally rises, they are good for warmer climates.
The downsides: It’s worth noting that this kind of manual roof vent relies on manual airflow and little air recirculation will be produced without wind and/or vehicle motion. So you need to consider other ways to get air in alongside the roof vent. Certain brands can be expensive, and installing a roof vent requires cutting into your van roof.
Fan assisted roof vent
If you’re looking for top-of-the-line ventilation, an electric fan-assisted roof vent is the ultimate solution. On these models, an integrated electrical fan provides maximum airflow in and out of your campervan.
One of the biggest advantages of an electric fan-assisted roof vent is its exceptional performance for moving air in and out of your campervan.
Fitting two electric vents will allow you to create the pinnacle of a campervan air recirculation system, you can set reverse rotations of the fans, meaning one will draw in fresh air in while the other expels the interior air out. Moreover, these vents can be used while stationary, providing continuous airflow to keep you comfortable and refreshed.
The electric fan-assisted roof vent, however, is the most expensive option. They require wiring into a 12-volt DC power supply, which adds a job, and can also be noisy when operating at high-power. Oh, and, don’t forget the whole cutting into the van thing again.
Picking a fan assisted vent
When choosing a roof fan for your van, it’s important to consider your needs and preferences.
You should decide whether you want an intake fan, an exhaust fan, or a fan that can do both.
Having two separate fans, one for intake and one for exhaust, is ideal for maximum ventilation. Additionally, a multi-speed fan can be a great feature, especially if you plan to use it while sleeping.
While a good roof fan may come with a higher price tag of around £300, it’s important to remember that if it’s one of your must haves then it’s money well spent, because it will provide numerous benefits in terms of comfort and health.
How to install a roof vent
We have a pretty comprehensive guide to making cuts in your van, and installing windows.
You should read both of these. Because of the content on those other articles, we’ll keep this one short and sweet. Your vent should come with it’s own set of instructions, but, in a nutshell, you want to:
- Choose the location: Select the best location for your fan based on your desired airflow. Typically, if you have windows in the front (cab) you’ll want to install it towards the back of the van. Some people prefer installing it over their stove/ near a bathroom, but that’s up to you. Don’t install it too close to the edge of the van, the part of your roof needs to be flat and not curved.
- Measure and cut: Once you have chosen the location, measure and mark the dimensions of your fan and use a jigsaw with a metal cutting blade to cut along the marked lines. Use a drill to make a hole big enough for your blade, to get you started. Take your time and make sure you’re cutting straight.
- File and paint: Once you’ve made your cut, file down the metal to remove any sharp edges and apply primer to prevent rust or corrosion.
- Apply sealant: Use a strong, weatherproof sealant to ensure your fan is waterproof and weather-resistant. Apply the sealant to the edge of the metal around the entire cut. Then, press the fan flange down onto the caulking and screw it in using the screws provided.
- Install the fan: Finally, place the roof fan in the cut and screw it to the flange using the provided screws. Apply caulking over all the screws to ensure a waterproof seal. Add a bunch more sealant, really make sure no water will get in. Connect up the wires if it’s a powered roof vent.
- Test for leaks: Before moving on to any insulation or ceiling construction, chuck loads of water on it.
What we did
As you might know, we bought an already made van that we ripped out and started again.
The benefits of doing it this way was that the included windows and vents were cut and in.
We have two opening roof vents, one above the bed at the back, and one above the living space. Neither are powered.
Before leaving, I considered putting in an electrically controlled vent. In the end, I deemed it to be too expensive an item. It’s something I will be changing before our next trip.
We were in the van during the heatwaves of summer 2022, and it was extremely hot and some nights, we were unable to get to sleep before 2am.
A way of pulling out hot air would have been really useful. You need some way of moving the air around when you are stationary, because passive ventilation just ain’t cutting it.
Even outside of heatwaves, there’s a good chance once you have your van you are going to be designing your life around spending your time in nice places, with warm weather, so having a way to circulate air is going to be important and we would recommend that you put serious thought into how you do it.