Is there any maximum length for a 3" fresh air intake pipe?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

JPapiPE

New Member
Hearth Supporter
I live in a mobile home and have bought the Englander 13NC mobile home approved wood stove. I know I'll have to connect the 3" fresh air intake pipe to the outside. My problem is that if I go straight from the stoves air intake to the outside, I'll only be 2-1/2' about the ground in heavy snow country. This area is also where the sloped metal roof drops it's snow. Last year the heavy snowfall and the roofs snow deposit covered 4 of my windows and the height of the snow fall plus the roofs snow drop made the snow height as tall as the eaves of my home. It isn't really an option to sink the 3" pipe into the floor and get my fresh air from beneath the mobile as it is all closed up with insulation and sheets of homosote. Plus it is a nightmare to crawl under this beast as it has only 14" of clearance from the ground to the bottom of the trailers bottom. If my stove will draw fresh air from a long length of 3" metal pipe I might be able to place the outside connection away from the major snow. I could also build a wooden chase and go vertically, but with either way I think we are talking some 10'-14' of length of fresh air pipe.
Any help greatly appreciated
 
i'll have to check , obviously the longer the run the less efficient it will be to an extent however i do not think a 10 ft run will hurt ya. maybe even increasing the longer part of the run would be an option as well. i'll do some checking and post what i find out.
 
Can't answer the OP's question, but please don't forget that extending the air pipe to get its mouth to clear major snow would also diminish your draft, since the height (air pressure differential) between chimney's top and air intake could get too low.
 
I would be amazed if the crawlspace were actually that tight, but it is probably a good idea to not involve that air in the combustion process. It would seem to me you could run it a considerable distance if you upsized it to 6". My rough rules on airflow would say 4X the allowable distance, but I defer to other's opinions on this...

Chris
 
I'd be curious if anyone else had thoughts on this. I am in a similar situation, looking at a 25 foot run for outside air intake, mine on a PE summit stove with 4" pipe. Wondering if I should upsize to 6" for the bulk of the run and the vent hood?
 
Would be interesting to know if you needed to use a fire resistant duct for this. If not, a guy could use relatively cheap 4" sections of storm pipe from HD to extend the intake tube. My intake pipe is aluminum flex and has always been very cold. Mine sucks crawlspace air from a ventilated crawlspace all year long, even when there is no fire.
 
Status
Not open for further replies.