What is it about Chimneys?

[Overwatch]

I live in Greencastle. Well, Putnam County to be more precise since I live out in the county, in the sticks.

Long story short, my fireplace does not draft well. When it is coldest or windiest, the smoke comes back into the house. The chimney is not blocked, we had it inspected last year when we bought the house. I think it is too short -- the roof line is higher than the chimney cap, so I think its dealing with some turbulence. I wish I could get an expert out here to tell me I'm wrong!

So, my quest for the past 2 months has been to find somebody, anybody who will actually service a chimney in Putnam County. Avon won't come this far west. Bloomington won't come this far North. Don Walton's in Cloverdale won't come out to see a Chimney -- they gave me the phone numbers to people who might do that kind of work, but they never answer their phones. Ever.

What does a person have to do to get a chimney estimate and buy an extension (probably). Someone, please, come take my money.

 

[atvdave]

A good place to get information... Hearth.com Forums Home

 

[PapaScout]

A little trick is to use the heat from a hair dryer, candle, etc in the fireplace or wood burner to get the cold-block to move. Once you get the cold air that's sitting in the chimney moving up you'll draw just fine. I like to use a lighter or match to check it. If the flame looks like it's being sucked up the chimney you're good to go. If not use the hair dryer.

 

[4sarge]

No expert by any means but the Chimney needs to be higher than the roof line by 2 - 3 feet if I remember correctly. That should be an easy answer for builders or stove installers to answer.

 

[Brandon]

Had the same issue on a house my family built years ago. Turns out it was to short and extended about 3 feet higher and solved the issue.

 

[WilsonMD]

The chimney should be two feet taller than any point on the roofline that is 10' away on a horizontal plane.

 

[CHCRandy]

Wilson is correct on the 10/2 rule....... Wood Stove Troubleshooting

 

[CountryBoy19]

The chimney should be two feet taller than any point on the roofline that is 10' away on a horizontal plane.

I didn't look up the specifics, I'm quoting from memory, but I'm pretty sure it is ANY structure within 10 feet. I would highly recommend that be applied to trees as well (they can interfere with air currents just the same as a roof). The actual code is that the chimney must extend a minimum of 3 feet above the penetration point and at least 2 feet above any part of the structure within 10 feet. Realistically, if your roof has anything greater than a very shallow slope (nearly flat) then the 3 foot rule trumped by the 10/2 rule. For example, my chimney protrudes 8 feet above the roof penetration to meet the 10/2 rule because I have a steep roof.

There is also nothing wrong with going higher than the rule to get a better draft but IMHO, there is such a thing as too much draft. I have problems with it because of my particular situation but I still have to meet code so I live with it.

 

[danimal]

Your chimney height has less to do with the direction of the draw and more to do with safety of the embers that may make it up the flue and the rate of draw (both in and out). A taller chimney may help create a higher pressure balance point, but it is not a guarantee.

Is your chimney on an outside wall of your house or inside your 4 walls? A chimney "bolted" onto an exterior wall will almost always allow the air in the chimney to become colder than the inside air of the house and cause it to downdraft.

But the downdraft has less to do with temperature and more to do with pressure. Your house has 2 pressure zones, + to the outside pressure, and - to the outside pressure. + pressure means air that wants to escape your house, and - pressure means your house wants to draw air in. Somewhere in your house, there is a balance point, where warm + air meets the cool - air below, called the neutral pressure plane, or that fine line where the pressure (not necessarily temperature) in your house is the same as the outside air. Your chimney also has it's own pressure plane relative to the plane of your house. When the pressure plane of the chimney is under the plane of your house your chimney will downdraft because it is an unrestricted entrance for air to enter the home to replace the + air escaping your house elsewhere. The real solution: lower your home's pressure plane (i.e. increase the indoor pressure of your house). The practical solution: raise the pressure plane of your chimney.

Check your other appliances. Make sure range hoods and bathroom fans aren't creating "extra" chimneys in your house. I use one of those 3M plastic window kits on my whole house fan come Halloween time each year to keep that sealed up. These will not only help increase your home's pressure, but also save you some money if they are drafting and allowing large amounts of conditioned air in/out of your home. I also give the dryer vent pipe a good scrubbing and clean the louvers on the vent real good.

Usually the quickest way to getting your chimney to begin drawing the right way is to open the nearest window. It will begin to cause the balance point for the pressure in your home to drop below the level of that in the chimney. Of course this will be letting a bunch of cold air into the house too.

If you have a gas fireplace/insert, does it have an option for a pilot light? The heat caused by the pilot will generally keep the pressure plane up in the chimney. Of course this wastes fuel, but it may be better than cold air pouring down it. Another solution may be to keep a couple candles going depending on what you can pick them up for vs. gas/propane (not recommended w/ kids or pets).

 

[mrjarrell]

Overwatch, if you can't get any chimney specific businesses to come out then just contact a mason. Whenever I've had anything done, other than cleaning, for my chimney I've called a mason. They're usually a bit cheaper and just as knowledgeable. After all they're the guys who usually build them.

 

[churchmouse]

There has to be air flow coming from somewhere to let the air up the chiminey. If you home is sealed up fairly tight there is no available air to rise even if heated. I have to crack a window (kitchen) a bit to get my wood burner flowing. There has to be "Combustion" air available.
Also, as already stated, the height is an issue.

 

[BigBoxaJunk]

My wood stove is near my utility room, which is vented to the crawl space and the attic. When the wood stove is burning, you can feel cold air coming under the utility room door and over to the stove.

 

[CountryBoy19]

My wood stove is near my utility room, which is vented to the crawl space and the attic. When the wood stove is burning, you can feel cold air coming under the utility room door and over to the stove.

Hence the reason why many modern stoves/inserts/ZC fireplaces include Outside Air-intake Kits (OAK). It eliminates 2 problems at once. It prevents your stove from consuming the heated inside air from your home and replacing it with fresh, cold air from outside. It also prevent negative pressure problems. If you are drawing cold air from outside directly into the stove there shouldn't be any draft issues related to chimney temperature or the dryer running in a tightly sealed home.

 

[churchmouse]

Hence the reason why many modern stoves/inserts/ZC fireplaces include Outside Air-intake Kits (OAK). It eliminates 2 problems at once. It prevents your stove from consuming the heated inside air from your home and replacing it with fresh, cold air from outside. It also prevent negative pressure problems. If you are drawing cold air from outside directly into the stove there shouldn't be any draft issues related to chimney temperature or the dryer running in a tightly sealed home.

Yup. All that is true. My stove does a great job and the minimal amount of fresh air is just enough to keep the area fresh.
The minus 18* air we experienced last winter had no ill effect on heating that we could tell.

 

[PapaScout]

Your chimney height has less to do with the direction of the draw and more to do with safety of the embers that may make it up the flue and the rate of draw (both in and out). A taller chimney may help create a higher pressure balance point, but it is not a guarantee.

Is your chimney on an outside wall of your house or inside your 4 walls? A chimney "bolted" onto an exterior wall will almost always allow the air in the chimney to become colder than the inside air of the house and cause it to downdraft.

But the downdraft has less to do with temperature and more to do with pressure. Your house has 2 pressure zones, + to the outside pressure, and - to the outside pressure. + pressure means air that wants to escape your house, and - pressure means your house wants to draw air in. Somewhere in your house, there is a balance point, where warm + air meets the cool - air below, called the neutral pressure plane, or that fine line where the pressure (not necessarily temperature) in your house is the same as the outside air. Your chimney also has it's own pressure plane relative to the plane of your house. When the pressure plane of the chimney is under the plane of your house your chimney will downdraft because it is an unrestricted entrance for air to enter the home to replace the + air escaping your house elsewhere. The real solution: lower your home's pressure plane (i.e. increase the indoor pressure of your house). The practical solution: raise the pressure plane of your chimney.

Check your other appliances. Make sure range hoods and bathroom fans aren't creating "extra" chimneys in your house. I use one of those 3M plastic window kits on my whole house fan come Halloween time each year to keep that sealed up. These will not only help increase your home's pressure, but also save you some money if they are drafting and allowing large amounts of conditioned air in/out of your home. I also give the dryer vent pipe a good scrubbing and clean the louvers on the vent real good.

Usually the quickest way to getting your chimney to begin drawing the right way is to open the nearest window. It will begin to cause the balance point for the pressure in your home to drop below the level of that in the chimney. Of course this will be letting a bunch of cold air into the house too.

If you have a gas fireplace/insert, does it have an option for a pilot light? The heat caused by the pilot will generally keep the pressure plane up in the chimney. Of course this wastes fuel, but it may be better than cold air pouring down it. Another solution may be to keep a couple candles going depending on what you can pick them up for vs. gas/propane (not recommended w/ kids or pets).

Isn't that what I just said?

 

[Overwatch]

Overwatch, if you can't get any chimney specific businesses to come out then just contact a mason. Whenever I've had anything done, other than cleaning, for my chimney I've called a mason. They're usually a bit cheaper and just as knowledgeable. After all they're the guys who usually build them.

I had a mason come out. He was knowledgeable -- but instead of telling me to make the chimney higher, he suggested I make the firebox smaller. He told me to start the first with a piece of plywood covering 2/3 of the firebox opening, let the fire heat up really hot, then remove the plywood. Is this good advice?

 

[Overwatch]

A little trick is to use the heat from a hair dryer, candle, etc in the fireplace or wood burner to get the cold-block to move. Once you get the cold air that's sitting in the chimney moving up you'll draw just fine. I like to use a lighter or match to check it. If the flame looks like it's being sucked up the chimney you're good to go. If not use the hair dryer.

We've done this, but it still seems to smoke on the coldest, windiest days. I try holding a burning newspaper above the flue. That does seem to be enough. Does it matter the height of the chimney for this trick to work -- does it work the same with very tall chimneys?

 

[mrjarrell]

I had a mason come out. He was knowledgeable -- but instead of telling me to make the chimney higher, he suggested I make the firebox smaller. He told me to start the first with a piece of plywood covering 2/3 of the firebox opening, let the fire heat up really hot, then remove the plywood. Is this good advice?

Might just work. It would concentrate the flow of air. Worth a try at least.

 

[armedindy]

what is it about me that made me click on a thread titled "What is it about Chimneys?"?

i dont know **** about chimneys

 

[Leo]

No expert by any means but the Chimney needs to be higher than the roof line by 2 - 3 feet if I remember correctly. That should be an easy answer for builders or stove installers to answer.

+1, that is what I was told by the guy that set the stone for mine. It worked fine.