O/T: Chimney question

I use a wood stove for heat(have furnace but propane is largely out of my budget); house is 26 x 74 on a full basement.

The wood stove works ok to heat the middle(located centrally, on north side of house) of the house but both ends are chilly.

I have a much larger wood furnace in the basement. However, I can"t afford $500 or so to put up another chimney.

I would prefer to use the basement wood furnace for main heat. This would eliminate pipes freezing(currently no heat in basement), house floors would be much warmer and I can plumb the blower to the existing furnace ducting, allowing me to more evenly distribute the heat.

Here"s the question: can I extend my existing 6" chimney down to the basement and run both stoves off it?

Existing chimney is 6". My thought is to adapt up to 8"(to allow more volume of airflow) at the ceiling, add a T adapter(and reduce back to 6") to attach to main floor wood stove. Remainder of chimney to basement would also be 8". I realize the adapter to 6" at the ceiling would be a choke point, but I can"t afford to buy all new stuff to replace it with 8" right now.

Total rise from basement through roof is about 20".

I expect that the smaller wood stove on the main floor of the house would only be used if we get extremely cold weather(located in south central MI). So most of the time, only 1 stove would be using the chimney.

I certainly don"t want to create a hazardous system. But unfortunately I"m on a very tight(read single parent, working class dog) budget. And it bugs the dickens outta me to hear my kids saying how cold their bedrooms are, so I gotta do something.

Suggestions and opinions are appreciated.

Thanks for your time,

Anthony

I don't know the monkey math of it, but it's common here to have one chimney service several floors of a building. I could imagine that modifying your existing chimney the right (safe) way would cost you that 500 bucks that you don't want to spend on the second chimney. Maybe a couple of fans to circulate the warm air? Good luck.

Dave

You may want to ask your insurance agent what he thinks. If your propane furnace is connected to the same chimney, the answer is NO!

Absolutely not . You will be messing up the drafting system & having smoke in your living courters . People that run 2 woodstoves up what appears to be one chimney actually have 2 seperate pipes inside that chimney .My dad & Brother both had experienced masons build their gorgous brick chimney with 2 flue pipes inside . One for gas furnace & one for woodstove .HTH ! God bless

You probably can. If you cap it off at the stove you aren't using. You can't use both at the same time because the smoke will come back in at the place with the lower air pressure.

8 inches to 6 inches should not be a problem, my wood furnace is 6" all the way up. 6 inches to 8 inches would slow the airflow and hinder your draft.

Are you planning to do away with the existing stove in this process?

Each wood burning stove needs its own chimney.

I think you can do it, not doing any math but looking at my really old (1800s) 2 story brick house it was built with 4 chimneys that went straight from the 1st floor up and served stoves at one time or another on all floors in all rooms. These were very simple unlined 8x12 brick ones. Nothing you would do today but they must have worked for decades for the oldtimers so I think you probably can pull it off. Advice re. changing diameters, I wouldnt do it, its not intuitive that big here and there is better as I dont think you want velocity changes in the smoke. If you got the 6in. go with it and see how it does, you can allways knock off the upstairs one and have saved a bunch of money keeping it simple. Good luck, keeping warm is tough work.

If your budget is so tight, apply for HEAP Money at your local Social Services Office to help pay for fuel to run your gas furnace. Either you are in dire need of financial help, which many people are, or an Ell-cheepo who puts money ahead of your families safty. Your $500.00 budget buys nothing but unsafe single wall stove pipe, and major code violations, resulting in insurance issues.

Legally in 2010 codes you probably can't. This affects your insurance, and maybe child services if something comes that way.

Practically it does work to do what you want, esp if you have an old loose poorly insulated house. If it's a new tightly wrapped wind-tight house then there can be issues.

I don't understand using an 8 inch for a portion of it all, and then choke back to 6 inch. Why bother with the 8 inch then.

What size is the bottom furnace shimney, if that is 7 or 6 inch output, then no it doesn't work tochoke it back to a 6 inch higher up, you need 8 inch all the way if the bottom furnace has 8 inch.

A wood furnace works so much better than a wood stove, block off the wood stove totally & just run a propper chimney up from the furnace - if it works on 6 inch you got simple. If it needs 8 inch, well then you need to put 8 inch all the way up.

--->Paul

Well, first off you spellt it wrong. Around here I think it must be spellt "Chimbley"

Gene

Maybe so ,,. but in 1981 before ordinances , We built a "Chimbly" that was 30ft in a 2 story 8 room Cross gable farmhouse .. Buck stove in living room below , shared chimney with a smaller cabinet type Wood stove on 2nd floor for extra heat when temps got in the teens .... worked just fine ,,

Main floor wood stove is 6", so my existing metal box through the ceiling is sized for 6" pipe and double wall pipe from metal box up through roof is 6". However, wood furnace in the basement is 8". That's why I was going to run 8" from the basement up to the ceiling, then adapt down to 6".

Would prefer to keep the main floor wood stove functional as a back-up unit, ie: if we get some exceptionally cold weather, if I have to shut the basement wood furnace down to clean it out or if the blower on it goes out, etc. I expect the main floor stove typically will not be used. Even though it will be attached to the chimney, the damper in the pipe will be shut, the door will be shut and the air holes will be shut. Seems to me it shouldn't affect the draft of the basement stove.


Thanks,

Anthony

Any relatively easy way to get central area heat into end rooms?? How many walls in between?? Cut some vents in walls near ceiling, put small fans in end room interior wall to pull heat from center and to blow into end rooms??
Elec heat possible?? Unless really drafty, even a low-output 300-500W heat source on during night hours would make a difference...

I understand the damper doors, etc. That part works, tho in 2010 it very, very likely is not to code in a dwelling. Not much at all is to code any more because there are so many reams of code..... Legal issues aside, I understand & it can work fine.

Your problem is an 8 inch furnace output implies it needs an 8 inch chimney.

You can't really reduce that down to 6 inch and expect it to work.

The extra 2 inches of smoke will try real hard to get around the dampner, etc. of your stove, and there you might actually be doing something deadly. Throttling backa chimney is not a good idea.

I don't think it is wise to throttle down the chimney to a 6 inch, when the furnace has an 8 inch output. I think that will give you major problems.

I'm only a simple dirt farmer, don't know much on heating & heating code, so just my opinion. Hope you figure out something to make it work properly.

--->Paul

If you ask the insurance agent, he'll shut the whole policy down. I've jumped through ALL of their hoops. I finally put in an outside boiler so I could have home insurance and wood heat at the same time. . .

And my insurance went up anyhow. . .

They are installing a water main in our neighborhood. S'posed to get a fire plug out in front of the house. I bet my insurance goes up again. . .

I have a low opinion of the insurance industry. . .

Paul

Anthony, have you tried running your propane furnace fan on "circulate" or "fan only"?

That might get some warmth to those outer rooms.

In the last house we lived in, I put the main cold air return right over the living room wood stove. Had a foot of insulation around the duct. I used an air conditioning thermostat near the wood stove to turn on the furnace fan, via relay. It made all the rooms within 5 degrees of each other. Worked real good in real cold weather, but in mild weather, the living room was HOT.

Just be careful. You've got a family to protect.
Paul

I'd just buy a electric baseboard heater for the kids bedroom and forget about improperly hooking up the wood burner in the basement. Where did the basement wood burner come from anyway? Seems odd having one just sitting there. Electricity cost can be found using a Kill-a-Watt monitor.

The toss pot used to freeze under my parents beds when they were kids.
An electric heater can use a whack of $$$ power over a winter is running 24/7.
T'ing a chimney tends to cause trouble.

Put a small insulated plenum with fan in the attic.. Run insulated ducts to the end rooms thru ceiling vents..Air will circulate back to center for even heating..

In my old shop, I have a wood stove with an 8 inch outlet which tapers down to 6 inch pipe. It goes into a suspended brick flue which is only 4x4 inside.
It draws well.
Richard

probably not, but I've been running two stoves in the same flue for nearly 20 years in my farm house. + the gas water heater in the basement and I know that's a no no as it eats up the mortar in the chimbly.

I don't know what the exact stats are. I think the insurance people say you are 10 or 12 times more likely to burn your house down with wood.

Many years ago a person installed a woodburner, burnt his house down and the insurance co didn't want to pay off because he installed a woodburner without telling his agent. Perhaps others could tell if they have had a bad experience with wood and insurance co.

Your answer may be here
National Fire Protection Association

Can a gas-fired appliance be connected to a chimney flue that serves a fuel oil-fired appliance?

Subsection 6.5.20 of NFPA 31 does allow such installations, either through separate connections or through a common connection provided certain conditions of Subsection 6.5.20 are met.

I'd advise you to do three things. Check your local building code, check with your responding fire department, and check with your homeowner's insurance company. As an insurance inspector, I can assure you insurance companies get EXTREMELY nervous when they see any wood stove, moreso when it's something a homeowner has put together himself.

If I encounter a wood stove when I'm inspecting a house, I have to fill out a separate report form on the stove. Besides details and photos of the stove and installation, questions asked on the form are, who installed it?, was it professionally installed?, after installation, was it inspected by the local fire department?, who cleans the chimney?, how often is the chimney cleaned?, etc.

You can obviously do anything you want, but you need to be aware you could wind up without homeowner's insurance. And if you do anything without your insurance company's knowledge they'll bail out if you ever have a problem relating to the stove.

I heat our house with a dual fuel furnace it can burn wood or coal in one combustion chamber and oil in the other. They use a common flue/chimney and a common plenum and blower. Most times when using the wood burner the blower does not kick on because the heat will move through the duct work like a gravity system. Hot air rises cold air sink. I also supplement the heat in a build with a vintage Round Oak wood burner it is on the second floor and the shop area is on the first floor. Once I have the burner good and hot I'll flip the thermostat to the fan function and circulate the heat through out he building. Works very well. The build is over 2000 sq. ft. which is similar in size to your house.

If you can't afford a second chimney, and can do it SAFELY, try it. but check out the furnace in the basment throughly. if someone bought it used, put it in and never finnished it thats one thing, But if it was used to heat the home, but then put out of service, thats suspect. There might be a crack in the firebox or some other safety issue. To check for a crack in the firebox, seal up the smoke opening, draft, ash door with plastic and duct tape, throw in a smoke bomb and seal up the door. it smoke comes out the hot air ductworks, you have a cracked firebox.

(quoted from post at 05:12:45 11/20/10) Anthony, have you tried running your propane furnace fan on "circulate" or "fan only"?

That might get some warmth to those outer rooms.

In the last house we lived in, I put the main cold air return right over the living room wood stove. Had a foot of insulation around the duct. I used an air conditioning thermostat near the wood stove to turn on the furnace fan, via relay. It made all the rooms within 5 degrees of each other. Worked real good in real cold weather, but in mild weather, the living room was HOT.

Just be careful. You've got a family to protect.
Paul

Click to expand...

I used to heat with a wood stove. It was a small simple cast iron "boxwood" stove from TSC. I built a brick and stone platform for it to sit on in a corner of the kitchen. The furnace was on the opposite side of the wall. I cut a hole in the wall. Cut a hole in the return air plenum and installed a filter rack. Then I built a "hood" over the stove. Basically the hood formed an "L" shape to box in the area in the corner above the stove. It extended down from the ceiling about a foot. . I then covered the walls and inside the hood with cement board. I used a 6" triple wall chimney from the ceiling out through the roof. I placed the stove on the platform, ran single wall from the stove to the triple wall at ceiling height. I then mounted a limit switch from a furnace out of sight in the hood and wired it to the blower motor on the furnace. I took some used galvanized sheet metal and made a heat shield to go between the stove and walls. When the stove would heat up the heat would rise causing the limit switch to switch on. That would start the blower motor on the furnace. The furnace would pull the hot air from above the stove through the filter rack into the return plenum, down through the furnace and distribute it via the ductwork throughout the house. I heated a poorly insulated 1250 SF ranch house with lousy windows in the country with that tiny little wood stove!
The stove would hold two 16-18" logs. We kept the house at 72-75 degrees all winter. My two month gas bill for January and February was $17. Not bad for northern IL in the 1980's.
I did make one modification to the stove. It burned too hot so I took a piece of round stock and formed it to match the sliding cast iron intake damper. I drilled and pinned it to the damper so it could close the air intake on the front and only leave an area on each end opened. We were able to control the fire much better. We also had a damper in the chimney. The stove, chimney, limit switch, bricks, etc set me back a little over $200 (1980's). My insurance carrier required the fire department to inspect the set up. That set up far exceeded my expectations.

We had 2 wood burners on the same chimney as well. Drafted fine, and worked fine, but forget about getting fire insurance.