Draft at 60 degrees

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SculptureOfSound

Feeling the Heat
Sep 9, 2017
372
Wisconsin, USA
Just curious if it's odd to have pretty good draft when it's 60 degrees outside. I had no problem getting a fire started in my Montpelier (had a few fires so far....going into my second season and was just itching to burn and also wanted to see if I had forgotten everything I learned last year).

I can't turn the air down all the way, and I have to leave it with more of a primary burn and less secondary, but other than that it has been burning great. No visible smoke out the chimney, no smoke on startup, no reverse draft prior to lighting the fire...nothing.

Is that odd given the outside temp? I only have 15' of liner above the insert, although the top of the liner is about 5' above the highest point of the roof (used rigid duraliner and have 4 extra feet sticking out, plus chimney was already higher (barely) than peak roofline).
 
Sounds like your one of the lucky ones!!! Being on the FD here we have had storms in the winter start off as snow then turn to rain with a rise of temps from 30's to 50's overnight, never fails we get that one call of a house "filling up" with smoke, when really its just weaker draft with a dirty chimney cap, its hard for people to understand that draft is dependent on multiple factors, outside temps and pressure differences are one of them.
 
I find it just takes more kindling in the shoulder season. I lit a fire yesterday when it was 55 and raining. No smoke spillage under normal operation. Fire burned great and I got the stove top up to 700f before letting it settle a bit. About this time I turned the primary air down to about 15% and then slowly opened it back to about 50% and let it burn down. My fuel load was probably 6-8 lbs, so very small. I had to tend the fire more than I would for a middle of the winter full box burn, but that's ok, the active flames were out before the 3hr mark. I did the same thing before bed but just turned it down to half and left it after the kindling burned down.
 
The TL/DR version is: get the flue hot ASAP and keep it hot and you won't have any problems. I can't wait for a liner and double wall pipe.
 
That's what I did too Spacebus. I did open the door after about ten minutes to add a couple medium splits and no smoke rollout which was nice.

I just wasn't sure if decent draft at 60 is unusual and if that likely means I will have too much draft when at say 0 or Ten below.

I did have to mod my insert and reduce the amount of air that can be pulled through the tubes as it was getting away from me before that. Now it seems to burn pretty good although still burns a bit fast (as in the speed of the air coming through the tubes, due to the high draft and restricted tube volume).

Not really able to add a damper as I only have maybe 6 inches of exposed flex liner which bends back through the damper, unless there is some kind of damper that could sit right at the appliance connector?
 
Just curious if it's odd to have pretty good draft when it's 60 degrees outside. I had no problem getting a fire started in my Montpelier (had a few fires so far....going into my second season and was just itching to burn and also wanted to see if I had forgotten everything I learned last year).

I can't turn the air down all the way, and I have to leave it with more of a primary burn and less secondary, but other than that it has been burning great. No visible smoke out the chimney, no smoke on startup, no reverse draft prior to lighting the fire...nothing.

Is that odd given the outside temp? I only have 15' of liner above the insert, although the top of the liner is about 5' above the highest point of the roof (used rigid duraliner and have 4 extra feet sticking out, plus chimney was already higher (barely) than peak roofline).
Not odd at all.

We are the same way. While draft is certainly better when is is cold and dry, I have no problem getting a fire going without smoke or draft issues when it is 60.
 
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Not odd at all.

We are the same way. While draft is certainly better when is is cold and dry, I have no problem getting a fire going without smoke or draft issues when it is 60.

Same here. We burn frequently when it's above 60. If the house is too cold then we burn. I even burn when the outside temperatures are higher than the inside temperature. I'm only on 12' of chimney. Almost no difference between warm and cold ambient temperatures. This is surely at least in part due to the thermostat automatically opening a little farther to let the fire breathe when the draft is weaker.
 
Draft depends on a lot of circumstances. In addition to the outside temp differential, the chimney and stove locations directly affect draft. So does flue system design, altitude, house location, and local atmospherics, winds & terrain. We have seen folks here that have short chimneys that draft fine and folks with taller chimneys that meet or exceed spec, but still draft poorly.

If your draft is decent at 60º consider yourself one of the lucky ones. We can have a decent burn at 60º, but I do need to be more mindful of how and when I open the stove door if I want to avoid smoke spillage. This is with a 20', straight-up, interior chimney.