Like a lot of people nowadays, I'm fitting a log fire into the back of a camper van but can't find the minimum height above the roof for the chimney. Ideally, it should be as low as possible for aerodynamic and roof clearence purposes.

Building regs state that the pipe should be 2' above the highest point on the roof and I've seen people blindly follow this with their conversions (which is ridiculous) but nobody says why. Air flow? Safety for thatched roofs? The most recent paper I've found on the subject was published in 1946 and doesn't address this issue.

The venting for the stove is entirely different anyway with a 30cm cubed combustion chamber, a 130mm internal sized flue, a 500cm straight pipe to the roof and a 3-5Kw output.

Is there some formula for a minimum chimney height above the roof? Or a university compartment specializing in combustion?

  • $\begingroup$ If there is no mathematical answer, I suppose I could go to Camp Quirky and do a survey of self-build vehicles. They should have a variety of sizes and be able to tell me the results they have had but there's always the factor of "Yes, I had that problem, too, I just assumed it was normal" afterwards. $\endgroup$
    – Mike
    Feb 19, 2020 at 22:33
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    $\begingroup$ What you need is a powered draft inducer in the stack up near the roof to pull a negative pressure on the entire system inside the camper. That stops smoke leaks, which are dangerous in small tight places. You also need a dedicated outside combustion air supply. You can always just run the pipe out the side and remove the external stack when roading. $\endgroup$
    – Phil Sweet
    Feb 19, 2020 at 22:52
  • $\begingroup$ Just curious, have you considered something like this? $\endgroup$
    – Phil Sweet
    Feb 19, 2020 at 23:15
  • $\begingroup$ Yeah, I really want to avoid removing the stack but I can set up a small vent near the base. I'm getting a diesel heater as well for when I'm stealth or only staying a while but the wood stove is for when I'm settled for a stay. Additionally, by liquid cooling one side with a heat exchanger, I get the bonus of hot water. Looks like I'll have to take a statistical approach to this problem. $\endgroup$
    – Mike
    Feb 20, 2020 at 12:00


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