In Room Blower/Fan - Sulfur Smell Problems

In Room Blower/Fan - Sulfur Smell Problems

PostBy: JRLearned On: Mon Aug 19, 2013 8:50 am

Last year I burned a Jotul 507 (now for sale on Craigs if you're interested) for 5 months straight. I had 5 inch pipe and some adjustable elblows coming out of the stove and up to a chimney thimble in the masonry wall above the mantel. I thought it would be a great idea to add an fan behind the stove to blow the hot air around the room. Boy, was I wrong! On several occasions I tried different configurations and angles (behind, in front, to the side, facing up, facing down, etc) and every time a massive amount of SO2 smell entered the house. This was all new stove pipe with the crimped ends facing up like you're supposed to with coal. Being new to coal then, I chocked it up to the nature of coal flue gases. Any breeze across the stove pipe pulled the flue gases right out of there. I said to myself, 'ok, no fans, just radiant heat from now on'.

This year, I have a chubby stove with 6 inch flue pipe, bought all corrugated elbows instead of adjustable, and used direct vent sealant in all the stove pipe connections along with self tapping screws. I'm even considering wrapping the connections in high temp foil tape and painting the foil tape black. Anything to avoid sulfer smells. To some extent a little smell is unavoidable when loading/reloading, but all my connections are/will be pretty tight.

So here are my questions: Anyone else have this problem where a little fan breeze and your house smells like rotten eggs instantly? What would I have done wrong to cause it? It's August, so I can't really test my new setup with a fan, but I'm hoping this year I can safely blow a little breeze on my Chubby to get some circulation going. The new Chubby's even come with blowers built in.
JRLearned
 
Stove/Furnace Make: Chubby Stove
Stove/Furnace Model: FrankenChubby

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: freetown fred On: Mon Aug 19, 2013 9:05 am

You probably have--BUT--check your chimney for any kind of obstruction--doesn't take much to screw up your draw. That should NOT be happening with the Jotul or the Chubby--- It is NOT the nature of coal flue gass's--You mention "ELBOWS" how many elbows are we talking here?????????????????
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: dcrane On: Mon Aug 19, 2013 9:19 am

My guess is your damper area of the fireplace is not sealed well (maybe you opened your damper and have your black pipe merely stuck up through it, high enough to reach the clay liner and no block plate at all?) A well fitting blocker plate should help but you can seal these as well with some high temp sealant or cement and gasket around the contact of pipe/blocker plate.

EDIT: I see you have a thimble above the mantel (again... make sure the fireplace is sealed to prevent pulling gases back down the chimney to your fireplace)... make sure if you have an ash drop in that fireplace you seal it (I don't think its your stove pipe of stove making your problems).
dcrane
 
Hand Fed Coal Stove: Crane 404

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Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: JRLearned On: Mon Aug 19, 2013 10:54 am

My father and I installed the clay flue tiles to tap into the left most flue in the chimney (there are 3) to serve the thimble. He is a licensed construction supervisor commerial and residential and built 3 of the houses we grew up in. The basement fireplace uses the left most flue in the chimney. It comes down on the left and there is a slanted shelf that runs down right to the fireplace. There is a damper in the fireplace that is closed. The thimble is heavy stainless steel with flange and it mortered in place. The flue tile runs from the left flue at a slant down to the right behind the thimble. It is an all clay tile flue, all well built in the 70's and we sealed it up good with mortar.

There is no obstruction, just some fly ash hanging on the walls of the tiles. We do have a stone or slate masonry chimney cap that seems to help block the effects of high winds. This is one of the reasons I've never put a barometric damper in place.

Draw has not been a problem, there is plenty. Though I haven't measured it with a meter, it seems like it's enough to vacuum your house with it sometimes.

There were two adjustable elbows: one on the back vent of the stove, and one at the level of the thimble.

There is no ash drop or cleanout door in the setup.

The sulfur smell is as simple as fan blowing on stove = sulfer smell. Fan not blowing on stove=no sulfer smell. Physics dictates that air flowing across the cracks in the stove pipe will create a somewhat lower air pressure outside the pipe . But wouldn't neccesarily mean that the presuure outside the stove pipe is less than the low pressure inside the pipe due to draw. If that were the case you'd have a total backdraft situation. I can't imagine a little fan air would cause backdraft unless I had some really, really low draw. But maybe air blowing across a leaky elbow would whip a little bit out of the cracks in the elbow???
JRLearned
 
Stove/Furnace Make: Chubby Stove
Stove/Furnace Model: FrankenChubby

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: franco b On: Mon Aug 19, 2013 11:12 am

Where is the fan located? If it is in the old fire place opening it could be drawing gasses down from around the damper area. I doubt it is coming from the stove. Get a manometer to help to know what is happening.
franco b
 
Hand Fed Coal Stove: V ermont Castings 2310, Franco Belge 262
Baseburners & Antiques: Glenwood Modern Oak 114
Coal Size/Type: nut and pea

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: dcrane On: Mon Aug 19, 2013 11:23 am

franco b wrote:Where is the fan located? If it is in the old fire place opening it could be drawing gasses down from around the damper area. I doubt it is coming from the stove. Get a manometer to help to know what is happening.


I agree with this statement^^^ (seal that old rusty, holey, delapitated damper and the bricks around it! toothy)
dcrane
 
Hand Fed Coal Stove: Crane 404

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: Lightning On: Mon Aug 19, 2013 4:06 pm

I think you are correct with your theory. A fan blowing across the pipe will create a low pressure area on the opposite side of the fan. Any open spaces in the joints would purge flue gas there. I also agree that a manometer is needed. The negative pressure in a chimney system is so low that nearly anything can influence it.
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: dcrane On: Mon Aug 19, 2013 4:15 pm

Lightning wrote:I think you are correct with your theory. A fan blowing across the pipe will create a low pressure area on the opposite side of the fan. Any open spaces in the joints would purge flue gas there. I also agree that a manometer is needed. The negative pressure in a chimney system is so low that nearly anything can influence it.


He said he tried blowing up down and around every way possible only to find the same sulfur smell and his pipe runs up to thimble over mantel (I'll be shocked if its coming from the stove pipe or that would mean any air movement from ceiling fans or anything would be resulting in the same problem). I think the negative pressure created in his fireplace opening from placing a fan in it is the culprit (sucking exhaust from gaps in brick or damper or ash drop or something like that) ... but ive been wrong before :(
dcrane
 
Hand Fed Coal Stove: Crane 404

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: freetown fred On: Mon Aug 19, 2013 4:29 pm

Yep, one theory is as good as the next. JR needs to check out quite a few suggested culprits. He'll get it figured out.
freetown fred
 
Hand Fed Coal Stove: HITZER 50-93
Coal Size/Type: BLASCHAK Nut/Stove mix

Re: In Room Blower/Fan - Sulfur Smell Problems

PostBy: Lightning On: Mon Aug 19, 2013 4:32 pm

Sure true as well. Placing a fan in the fire place blowing outward would create a low pressure area in the fire place resulting in flue gases purging from any opening, pipe joints, primary and secondary air feeds or possibly down thru as you suggested partner :)
Lightning
 
Hand Fed Coal Furnace: Clayton 1537G
Coal Size/Type: Nut Size / White Ash

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