Gas locker & drop-out vent calculator
LPG is heavier than air, so a leak pools in the bottom of the locker. That is why the locker is sealed from the living space and has a vent in its floor that can never be blocked — and why inspectors measure it.
Optional — leave blank to just get the requirement.
Minimum internal locker
370 × 370 × 730 mm
Required drop-out vent
10000 mm²
…or a round vent of
Ø 113 mm
Full bottles add
26 kg
The 100 cm² minimum governs at this locker size.
The locker must be sealed from the living space, open only to the outside, and contain no electrical fittings. Bottles are strapped top and bottom; a 30 mbar regulator is replaced 10 years after its stamped date.
Planning figures, not certification. Standards are summarised for builders; your inspector, your van's plate and your own measurements always win.
How this is calculated
- The box is sized from the bottles: 30 mm clearance around each for straps and hands, plus 150 mm of headroom above for the regulator and pigtail.
- The drop-out vent is the greater of 100 cm² and 2 % of the locker floor area. On normal one- or two-bottle lockers the 100 cm² minimum is what governs.
- Full bottle weights are included so you can carry them into your payload budget — two 11 kg propane bottles are 52 kg of it.
Sources
- EN 1949 — LPG installations in leisure accommodation vehicles
- DVGW G 607 — German gas system inspection (every 2 years)
- Qualigaz inspection practice (France)
Questions builders ask
How big does a camper gas locker drop-out vent have to be?
The greater of 100 cm² and 2 % of the locker floor area, under EN 1949. On a normal one- or two-bottle locker the 100 cm² minimum is what governs — that is a round vent of about 113 mm diameter, in the floor, where it can never be blocked.
What size should a camper gas bottle locker be?
Size it from the bottles: 30 mm of clearance around each one for straps and hands, plus 150 mm of headroom above for the regulator and pigtail. The locker must be sealed from the living space, open only to the outside, and contain no electrical fittings.
How much do camper gas bottles add to the payload?
More than builders expect, because the steel counts. Two full 11 kg propane bottles are about 52 kg — roughly a fifth of the entire EN 1646-2 payload reserve on a 6 m two-berth van. Carry the full weight into the payload budget, not the gas weight.
Keep reading
Plan the whole van, not just this number
VanPlot is a 3D layout planner for camper conversions. Place real components in your real van and watch weight, axle loads, power and cost update live — this calculator is one panel of it.
Who makes this
I'm Vladimir. I'm planning my own conversion, and none of the tools I tried could tell me whether a layout would fit or what it would do to the rear axle, so I made this one. I work on it alone. If something's wrong or missing, write to me — the address goes to my inbox.
Vladimir Šterjoski