Negative pressure? smoke coming in

rtpassini

New Member
Aug 12, 2019
9
plymouth, wi
So this was a fun weekend. We've been building a small 600ish sq foot cabin. all open with a small loft. Ive had my 94 jotul series 8ap burning a few times now. Well last night after completing more insulation and drywall, I woke to the smell of smoke. Went out and saw good puffs of it coming our the top damper vents. Flue temps were still in the 4-500 range, so I know it was drafting good. (this is all new pipe, so I knew there was no clog). due to the smell i opened a window to help clear it out. after that I didnt see it happen again. Im going to assume this is due to negative pressure? This is all off grid, no power or running water so options for moving air is limited (working on solar next year, just a generator now and a compost toilet) I have no problems just cracking a window for exchange, but when it gets to -30, that wont be so much fun. Any ideas? We have a ceiling fan that runs at night to help circulate the heat, but without positive pressure, that doesnt really matter.
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
20,589
central pa
So this was a fun weekend. We've been building a small 600ish sq foot cabin. all open with a small loft. Ive had my 94 jotul series 8ap burning a few times now. Well last night after completing more insulation and drywall, I woke to the smell of smoke. Went out and saw good puffs of it coming our the top damper vents. Flue temps were still in the 4-500 range, so I know it was drafting good. (this is all new pipe, so I knew there was no clog). due to the smell i opened a window to help clear it out. after that I didnt see it happen again. Im going to assume this is due to negative pressure? This is all off grid, no power or running water so options for moving air is limited (working on solar next year, just a generator now and a compost toilet) I have no problems just cracking a window for exchange, but when it gets to -30, that wont be so much fun. Any ideas? We have a ceiling fan that runs at night to help circulate the heat, but without positive pressure, that doesnt really matter.
What do you mean by top damper vents?
 

bholler

Chimney sweep
Staff member
Jan 14, 2014
20,589
central pa
This is a jotul cat stove correct? If so they were extremely temperamental your wood needs to be very dry your draft needs to be perfect not to weak not to strong. And even then they are not very durable
 

begreen

Mooderator
Staff member
Nov 18, 2005
81,123
South Puget Sound, WA
Could be the fire needed more air and better draft. How tall is the flue from stove to cap on this stove? What were the outside temps?
 

Woody Stover

Minister of Fire
Dec 25, 2010
11,757
Southern IN
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redmanlcs

Burning Hunk
Nov 20, 2017
148
West Virginia
Funny thing, in all my years of burning, I have never had a back pressure issue.... I hear of it happening, its just never happened to me, even on cold morning startups or warmer temps when draft would be questionable. I don't know why.. guess i have been lucky.....