vent question

curiousity kills

Can the laderal length of a vent be longer than the vertical?The existing is a 6" b-vent Total vertical 6 feet on a 80% 800000 btu induced draft 12 feet away.So the laderal is twice the distance.This is a furnce in a shop garage close to the roof.Thanks for any help.

Ken_8

You are almost off the charts with that combo,

however, it may work! Why do you ask? What's the basis of your inquirry?

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curiousity kills

vent

Currently there is a ceiling hung gas modine type heater.We are building a plateform for storage and want to install a floor mounted furnace 80% but use the same b vent chimney with the furnace moved over.I cant find anywhere in the nfg code about laderal length more than height.

jeff_51

since it is induced draft

you can go longer laterally than vertically but you musr follow the the specs on the blower or heater if it is built in blower. Don't exceed this or you can get into manoxide problems dumping into the space. There should be a chart or graph on the heater install sheet. If you don't have one, get the manugacturers name and model no and you should be able to get the specs from the rep or co pretty easy

jeff_51

if the furnace does not have induced draft

than you most certainly cannot go longer laterally than horizontally. I don't have my umc handy or I would look it up, but off the top of my head the lateral is about 15% of the vertical

curiousity kills

vent

Thanks jeff I will check that

Michal

check codes

check with nfpa i think 42 or 47 not sure or look online in the www.metalbestos catalog, there is a maximum length for laterals, just do not know it off the top of my head

Michal

check codes

check with nfpa i think 42 or 47 not sure or look online in the www.metalbestos catalog, there is a maximum length for laterals, just do not know it off the top of my head