Ventilation Requirement Calculator
Fan CFM/m³h needed for your van volume and air changes.
About the Ventilation calculator
Use this ventilation requirement calculator for van heating, gas & ventilation. Fan CFM/m³h needed for your van volume and air changes.
Enter your ventilation details
Match a fan or vent to the CFM figure. A 100 mm Maxxfan moves up to ~900 cfm; passive roof vents are ~30–60 cfm at typical wind.
Your ventilation results
Volume
18.98 m³
Required flow
76 m³/h
4 air changes / h
CFM
45 cfm
L/s
21.1 L/s
Why ventilation matters for van heating, gas & ventilation
Plan with confidence
Getting your ventilation numbers right early avoids costly rework, undersized components and surprises on the road.
Related heating, gas & air tools
Pair this with the rest of our heating, gas & air calculators to plan your full van conversion.
Ventilation calculator FAQ
- What does the Ventilation Requirement Calculator do?
- Fan CFM/m³h needed for your van volume and air changes. It is designed for van heating, gas and ventilation so you can plan with confidence.
- Is the ventilation calculator free to use?
- Yes. All VanTools calculators, including the Ventilation Requirement Calculator, are free to use with no sign-up required.
- How accurate are the ventilation results?
- Results are estimates based on the values you enter and standard van heating, gas and ventilation assumptions. Always sanity-check against manufacturer data and your real-world conditions.
- Can I share or save my ventilation calculation?
- Yes. Use the Share button to copy a link that includes your inputs, or use Export to download a PDF or image of your results.