Too much draft?

[abdickins]

Brand new member to the forum here, looking for some help.

I have used freestanding coal stoves for years and have been pretty happy with the results. We recently purchsed a home that had fireplaces instead of a woodstove hookup, so I went out and purchased an older Glacier Bay wood/coal stove insert with blowers. The flue size on this particular chimney is 18" x 18"! This house is 3 stories and rather tall, so the chimney is approximately 40' tall. The house is also located near the top of a hilly area (southern NH, so we're not talking extreme altitude here) where it seems to be quite windy on a regular basis. The outlet on the stove calls for a 6" pipe. I ran a 14" long pipe up to the damper and used some sheet metal to try and block off the rest of the opening.

When I initially installed the insert, I pushed the stove into the fireplace to the obvious point that the previous owners had it (obvious becauses of the rust-line since they didn't have a chimney cap and rain got in and on it. They also never had any stovepipe attached! They just shoved it into their fireplace, put up the steel plate 'surround', and started it up. They claimed they used this stove to heat most of their 2,000 S.F. home. I got a fire going quite easily but the heat output seemed less than it should have been. I realize that it will not be as effective or efficient as a freestandning stove, but it seemed that most of the heat was headed up the chimney.

So I bought about 4' of the flexible chimney pipe and ran it through the damper opening, stuffing unfaced insulation all around the pipe/opening. I realize that the flue is rather large for a 6" pipe, but my budget is limited and really can't afford to run 40+ feet of this up to the top. I also pulled the insert out an additional 8" or so, trying to maximize the surface area of the stove exposed to the room. Put the 'surround plate' back on and let her rip. Again, a VERY strong draft and the fire got going very easily. Again, it seems that all the heat is going up the chimney (because of the strong draft) instead of into the room.

One item that I am working on is getting a cap put on the chimney. This is usually recommended to stop downdrafts - how much will it help to reduce the "too strong draft" I currently have?

Looking for any other ideas/suggestions without breaking the bank. It would seem that a barometric damper might help, but can I put one of these on a pipe that is behind the plate sealing off the fireplace opening? Those are supposed to pull room air into the pipe, but the room air is (theoretically) cut off at the that point. I am considering getting a freestanding stove, assuming I have enough clearance at the front/sides and running the stove pipe up into the chimney, again blocking off as much of the damper opening as I can.

Thanks in advance for all the help!

 

[Corie]

It's hard to believe that a 6" round pipe with a cross-sectional area of 28.26 in^2 being vented into a chimney with 324 in^2 is giving you any draft at all? This is the equivalent of transitioning a 1" copper pipe to
and 11.5 copper pipe. Imagine water running through them at the same rate and you could see why I think a problem should exist.

With the doors open, I'm sure you see the flames being pulled up the chimney, but when running closed down at all, there HAS to be extremely rapid cooling occuring on the flue gases as they leave the stove.

Other's will weigh in, but the situation and installation you have dictates different conditions than what you're describing.

 

[abdickins]

Thanks for the repsonse, but believe me, there's a draft and it's strong. If I shut the main door and the ashpan door, leaving open only the small "vents" on the ashpan door, I can still see and feelthe fire burning very hot. There's not a trace of smoke being backed into the stove or room (something which I'm familiar with on other stoves when Ihave started them with a poor draft). I have been reading some other articles on a "too strong draft" and one mentioned that additional elbows will slow it down. Any comments?

 

[elkimmeg]

This is a clasic example of how not to install a stove. No damper plate direct connect stuffed with fiberglass. the old sotve probably is not labled or listed venting into an 18/18 flue
But is works and pull a strong draft? how can this be, it defines logic? Simple answer the stove all gaskets if there are any are shot. The loading door and ash pan air is escaping past them,
it is creating a blast furnace effect. The stove can't be controled by its inlet air regulators. This is one dangereous situation and installation for a runaway stove . All the heat is going up the chimney because there is no air control ,to control the burn and hold it in the fire box Pulling it out and having fiberglass as you only means of block off in a 18/18 chimney this situation could not be more dangereous. I suggest you add to your life insurance policy. No homeowners insurance company will pay out ,if that stove causes an incident you live threw,, including a real possibility of carbon monoxide

 

[elkimmeg]

You came here looking for advice letys see if we can. not comming down hard on you but there is a reason I have an inspector job , that is to make sure these situations don't exist Sorry probably not what you expected but ...