Roof Vents & Fans for Campervans
Compare the Maxxfan, Fiamma, and Dometic options, then follow our step-by-step guide to cutting your roof and fitting a vent that keeps your van cool, condensation-free, and comfortable.
Why Every Campervan Needs a Roof Vent
Condensation Control
Breathing, cooking, and wet gear all produce moisture. Without ventilation, condensation will form on cold surfaces, leading to mould and damp. A roof vent running overnight eliminates this.
Temperature Regulation
Vans heat up extremely quickly in summer. A powered fan vent can drop the interior temperature by 10–15°C in minutes. Essential for comfortable sleeping in warm weather.
Cooking Fumes
Cooking in a van produces fumes, steam, and CO2. A roof vent running while cooking keeps the air fresh and safe. Critical for gas hob users.
Product Comparison
| Product | Type | Price | Airflow | Rating |
|---|---|---|---|---|
| Maxxfan Deluxe | Powered Fan Vent | £280–£350 | 900 CFM | |
| Dometic FreshLight 1400 | Fan Vent with LED Light | £200–£280 | 600 CFM | |
| Fiamma Turbo Vent | Manual Vent | £60–£120 | N/A (manual) | |
| Dometic Heki 2 | Skylight/Vent | £150–£220 | N/A (passive) |
Pros
- Best airflow of any roof vent
- Rain sensor closes it automatically
- Remote control is very convenient
- Can be used as intake or exhaust
- Extremely reliable — popular in US RVs for decades
Cons
- Most expensive option
- Larger profile than some alternatives
- Requires 12V power connection
- US product — some find parts harder to source in UK
Key Features
Pros
- Built-in LED light is very useful
- Sleek, low-profile design
- Good build quality
- Popular in UK market
- Dometic brand reliability
Cons
- Less airflow than Maxxfan
- More expensive than basic options
- LED adds complexity
- Some models lack rain sensor
Key Features
Pros
- Very affordable
- No electrical connection needed
- Simple and reliable
- Fly screen included
- Good for budget builds
Cons
- Manual only — no fan
- Must open/close manually
- No rain sensor
- Less effective ventilation than powered options
- Basic design
Key Features
Pros
- Excellent natural light
- Large opening for ventilation
- Blackout blind included
- Fly screen included
- Beautiful panoramic view
Cons
- No powered fan
- Passive ventilation only
- Larger cut required
- More expensive than basic vents
- Heavier than fan vents
Key Features
Step-by-Step Fitting Guide
Choose Your Location
Position the vent towards the rear of the van, above the living/sleeping area. Avoid positioning it directly above the bed (rain ingress risk). Check there are no structural ribs or wiring in the chosen area. The vent should be roughly centred left-to-right for aesthetics. Avoid areas near the cab — you want ventilation over the habitation area.
Mark the Cut Line
Most roof vents require a 400×400mm cut opening. Apply masking tape to the roof in the cut area. From inside, drill four pilot holes at the corners of your marked cut area. These holes will be visible from the outside and allow you to mark the cut line accurately on the roof.
Cut the Opening
Using a jigsaw with a fine-tooth metal blade, cut along your marked line. Work slowly and steadily. Keep the jigsaw base flat against the roof. Have a helper inside to catch the cut-out panel — it will fall when the cut is complete. The cut edges will be sharp.
Treat the Cut Edges
File all cut edges smooth. Apply rust treatment (Kurust or similar) to all bare metal immediately. Allow to dry, then apply primer. This step is critical — bare metal on a roof will rust very quickly due to water pooling.
Fit the Roof Frame / Adapter
Most roof vents require a raised frame (adapter/riser) to account for the roof curvature and insulation thickness. Apply a bead of Sikaflex 221 sealant to the underside of the frame. Position the frame over the opening and secure with the provided screws. Ensure the frame is level.
Fit the Vent Unit
Lower the vent unit into the frame from above. Secure with the provided screws or clips. For powered vents, route the 12V cable through the frame before securing. Apply a final bead of Sikaflex 221 around the entire perimeter where the vent meets the roof.
Connect Electrics (Powered Vents)
Connect the 12V positive and negative wires to your leisure battery circuit. Most vents draw 2–5A at full speed. Fit an inline fuse (5A) close to the battery. Route cables neatly through the van ceiling. Test the fan at all speeds before fitting interior panels.
Fit the Interior Trim
Fit the interior trim ring/frame from inside the van. This covers the cut edges and insulation. Most vents include an interior trim ring. Secure with the provided clips or screws. Test the vent opens and closes fully without obstruction.
Tips & Common Mistakes
- Run the fan on low overnight to prevent condensation — even in winter
- Use the fan in extract mode while cooking to remove fumes
- A Maxxfan rain sensor is worth the extra cost in the UK
- Fit a 5A inline fuse close to the battery for the fan circuit
- Measure the roof curvature — you may need a curved adapter/riser
- Fit the vent before insulating — much easier to route cables
- Test for leaks with a hose before fitting interior ceiling panels
- Consider a second vent at the front of the van for cross-ventilation
- Skipping rust treatment on cut edges — roof leaks cause serious damage
- Positioning vent directly above the bed — rain ingress risk
- Not using a riser/adapter for curved roofs — poor seal
- Forgetting to fuse the 12V circuit — fire risk
- Using the wrong sealant — use Sikaflex 221 for sealing
- Not testing for leaks before fitting interior ceiling
- Positioning too far forward — poor ventilation of habitation area
- Not accounting for insulation thickness in the riser height