Harder to start a draft on a wamer night?

[fugazi42]

We've been burning for about two weeks this year- only at night just to keep the house temps from dropping below 60. I haven't had much trouble getting a good draft going, until tonight. It's currently 62 inside our house and 53 outside. Is it harder to get a draft going up the chimney when the outside temperature is fairly low like tonight?

I tried for a while to get the draft going on our Jotul 500 which has an external chimney, and just couldn't make it work. The past few nights when outside temps were in the 40s it wasn't a problem. I eventually got the draft going in our insert, which has a full-length liner in a brick chimney, but not without getting a decent amount of smoke in the house.

Thanks!

Josh

 

[cmonSTART]

Yup. Warm air rises, but if the air inside and outside are nearly the same temperature, there is no "warm" air. No differential means weak draft.

 

[glassmanjpf]

I find that if the temp outside is not going down into the 40's I won't fire it up.

 

[cmonSTART]

I tried that argument with my wife but lost. She needs it warmer than 60 in the house.

 

[Corey]

Damp air will make a difference too - as damp air is less dense than dry air, it is equivalent to having warmer air. A couple of times a year I'll have a complete 'reversal' where a cold night will chill the house to ~60F and the next day will turn off really sunny and warm, so it may get to 70+F outside. Open a door in the house and the cold air wants to pour out just like water would...and suck air down the flue to balance everything out.

The best solution I've heard to get the draft going would be to aim a hairdryer up the flue...you get the 'push' from the fan, plus the heat...should get a 'plume' of air moving in the right direction, plus no fumes. Second best I've heard was a propane torch. Again, you get hot air - and not too much fumes off the propane. Next on the list would probably be the old 'newspaper up the pipe' trick, which may be a bit easier, but then you've got the smoke from the paper if everything doesn't take off.

I seem to have pretty good luck by using a larger pile of kindling...something that I know will burn for a while and I can light it and close the door until it flares up and gets the draft moving.

 

[fugazi42]

Thanks guys- this confirmed my suspicion.

Is the opposite true as well? Is it easier to get a draft going in colder weather? I would think that in cold weather the greater density of the cold air sitting in the stack would make it harder for the warm air to initially make it way upwards. If it isn't obvious already, thermodynamics isn't my specialty.

Cozy- your idea of using the hair dryer is close to what I use. I posted a few months back about the trouble I had last winter starting my Jotul 500 even in cold weather. Some of the folks who responded recommended using a hair dryer or heat gun to warm up the flue and get the draft going. I picked up a cheap heat gun and used it a few times with great success- so far no smoke in the house. The heat gun is ideal since it puts out a tremendous amount of heat with only a small amount of air movement to stir up ash.

Thanks again,

Josh

 

[EatenByLimestone]

In warmer weather I light a few sheets of paper at the cleanout door of my chimney. It does the same as the hair dryer and makes sure I don't smoke up the back room trying to get the stove lit.

Matt

 

[chad3]

EBL,
Did the same thing on my first light this year and the stove was sucking very well (oxymoron?). Twist up a piece of newspaper and hold up the flue. Mine started drafting after that and I haven't even had a bit of soot on the glass. May be my wood that has sat inside since last year, but pulled very well either way. Not burning tonight, wish I was, air is very heavy and windy and a bit warm outside (not inside).
Chad

 

[trailblaze]

last night it was in the 50's and rainy.... the house was in the low 60's and i wanted to heat it up a bit....

the fire was hard to get going, but for some crazy reason once it was buring it REALLY took off... i had the air control completely closed and the fire was always roaring?

 

[ansehnlich1]

I ball up about 8 or 10 sheets of newspaper, throw dry bark or split kiln dried kindling on top, then 3 splits of lightweight wood, boxelder or pine or sycamore. Then I loosely ball up 2 more pieces of newspaper and put them in the front of the firebox at top. I light them first, then the paper in the bottom.

I let the side door cracked open about an inch until the temp on top of stove reaches 200F or more., then close 'er up.

Last night I did this when outside temps were 62 degrees and it worked fine.

Oslo hooked up to outside masonry chimney here, 8x8 clay flue tile.

 

[billb3]

Having had several "outside" chimneys - thay can be difficult to get a draft going when they are cold.
If you have a lot of your chimney outside and therefore a "cold" chimney then it sometimes helps to envision the air core as a slug of cold air that needs to be purged (as if it were an ice cube in a water hose maybe) or melted with a small fire first to push that slug of cold air out. Has to be done slowly, massaged out even.

 

[velvetfoot]

Cracking open a window, then pre-heating is key, in my opinion.

 

[Brian VT]

I just installed a through-the-wall class A chimney for my stove in the basement.
It's 54 deg. here but I had to try out my new stove and chimney. I expect a poor draft , especially with this setup.
I stuck a ball of newspaper in the stove collar and lit it. It sounded like a jet engine for about 30 seconds and then, whoop, it got sucked up the chimney.
I lit a fire and got no smoke in the house. I hope it works this well all the time.

 

[Dustin]

My stove is the oppisit. The second I night the paper, and close the door leaving it cracked with the air open it ROARS. Almost like a blowtorch. I little scary!

I have an SS lined interior masonry chimny. about 15 feet high.

 

[fugazi42]

Just thought I'd provide an update to my situation- I gave up trying to get a draft going on my Jotul 500 with the external chimney in warm weather. I have much better luck starting a draft with my insert when the weather is warmer.

Tonight it's supposed to dip down into the low 30s here in CT so we decided to fire up the Oslo. It's about 40 outside and 64 inside. I tried to use the heat gun to warm up the stove and get the air flowing in the right direction. After 30 minutes it managed to heat the stove up to about 120 degrees, but it couldn't get the draft going. I tried what Brian suggested and wadded up news paper in the stack (using the clean-out access) and lit it. I wasn't prepared for the WOOSH that followed- it sounded like a jet taking off. It must have been pretty loud inside as well, judging by the look on my wife's face when I came inside. This trick worked perfectly and I'll think I'll use it in the future. I did manage to start a small fire outside when some of the newspaper that fell out of the chimney hit the dry leaves on the ground, but that's much better than a house full of smoke! Hopefully it will work as well when it gets really cold out.

Josh

 

[Brian VT]

JI did manage to start a small fire outside when some of the newspaper that fell out of the chimney hit the dry leaves on the ground, but that's much better than a house full of smoke!

You might want to take a poll around the neighborhood about that. LOL
The chimney cap screen let that through and it made it to the ground still burning ?

 

[begreen]

Did you check the horizontal pipe coming out of the stove? Is it pitched about 3/4" higher on the exterior flue side? It should be. Does this stove have an outside air kit? If the answer is yes to both questions then it seems like it would be worth considering a reconfig of this stove considering the draft issues, even in cold weather.

(broken link removed to http://www.woodheat.org/chimneys/evilchim.htm)