Masonary Chimney Question?

I thought this was going to be an easy deal, once I made up my mind to go with a masonary chimney the hard part would be over. But no there has to be much more to this, I know one thing I'm getting a headache. I did do a google and here is what Hitzer says:


C. For HITZER models the chimney should be 8 inches by 8 inches of a tile lined
masonry construction, or metalbestos or a equivalent (U.L. listed) 8" insulated metal
chimney. An effective height of 20 feet or more is desired, and 15 feet would be
considered minimum. The top of the chimney should be at least 3 feet higher than
the roof at the point of exit. With pitched roofs, the top of the chimney must be at
least 2 feet higher than any point on the roof within 10 feet of the chimney. Check
with your local building inspector for local building code compliances. The ideal
insulation would be for the chimney to extend below the thimble with a clean out
door.


No that being said I have also read that if you have a bad draft, one thing you can do is make the chimney taller.

Yanche wrote:

coaledsweat wrote:I'm no expert on chimney construction, but this ought to keep you busy.

I think we need a coal chimney expert. Take a look at this link:

http://www.repp.org/discussiongroups/re ... 7-2003.xls

It's a calculation for the combustion of wood in a cooking stove. Note how the author has carefully calculated the moles of gases produced by burning the wood, added excess air and then determined chimney draft. Anyone want to port the calculation to Anthracite coal? Formula C240 H90 O4 NS. I know get a life.

Good heavens Yanche! Now you are scaring me!

Hello Woody30, a couple of questions.. what other buildings, lines of tall trees, hills or valleys are near your house?? If you are in a low area, with tall trees around, or have several two-story houses nearby, then you will in effect be in a valley, and may have issues with a minumum size chimney.

If your home is on high ground, without any blocking buidings or tree lines, then a chimney as described by Hitzer should work fine for you.

As posted above, having more chimney than needed is better than less. But you do have the option of building to the Hitzer-described minimum, then if you feel you need more chimney, you can bring back your mason, and add several more courses of chimney block to raise the height.

Another variable that has not been mentioned yet are weather variables.. Are you planning on starting to burn coal early, like November and burning late, like April?? When the outside temps rise, the draw from a chimney decreases, so this can change the design requirements of your chimney.

Yet another variable is your home, is it a tight, modern home with well sealed windows and doors?? If so, then your chimney will have a harder time drawing air through your coal stove.

I believe that if you provide an outside source of air to the inlet of your stoker motor, or to the air inlet area of your stove, you will be able to function well with a chimney that is 18-20 above the thimble. Without an outside air source, the chimney must be strong-drafting enough to overcome bathroom vent fans, cooking stove vent fans, clothes dryer venting. If all the mentioned appliances are running at the same time, then there is a significant draw on the house, and a chimney must have more draft than this to keep from reversing flow. With it's own outside air source, then this scenario isn't a problem.

My recommendation, without knowing the placement of your home would be to go with an outside air source and a 24' chimney, this would be 6' above your peak, a foot or so less may be fine if you don't have any tall trees, hills or buildings blocking your home. This would provide roughly 18' above your thimble, and with it's own outside air source, the coal burner and chimney should function fine.

Hope this helps. Greg L

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Greg, Thanks again for more info I appreciate it. I'm on top of a hill and there are no trees or buildings near my home. Where I'm thinking about putting up this new chimney is at the end of my livingroom on a end wall. Now my house juts out 5' in the center from the other two ends. In other words I have a 28 x 28 garage, then a 32 x 28 Lr, Dr, Kit, then another 28 x 28 for the three bedrooms and baths. The chimney will go in the center of the 5' jut on the garage end. Hope I explained that OK. So my concern is that since this will be about 2.5' from the eve front of the house, I'm thinking its going to look awefull funny with a chimney over my peak which is about 16' away from the chimney. As much as I would like the masonary chimney, I may go back to my other option putting the stove closer to the center of the house and go metal pipe. I know from what you guys say about the chimney being higher is better, especially for coal. But its really hard to get the wife to go along with this whole coal thing to begin with. Tim

If putting the chimney in the living room near the center of the house will end up with the chimney exiting at the high point of the roof peak, then this may be the way to go.
Is your house on a slab or crawl or basement?? With a slab, you can build a masonry chimney inside on the slab. Otherwise, you can get away with only about 3' of SS insulated chimney above the peak, so your costs may be the same with SS.

And a good insulated SS chimney won't be as critical for height as a masonry chimney. This is because the hot gasses will be able to retain their heat better in the insulated chimney.

I'm a big advocate of outside air sources for heating appliances. Any air going up a chimney has to come from somewhere.. So the chimney puts a negative pressure [slight vacuum] on the house. Then every slight air leak around windows and doors become a cold air infiltration point. If an outside air source is placed at the base of the stove, then the chimney will put very little if any vacuum on the house, and the effectivness of the stove will be vastly improved.

I'm heating my drafty old farmhouse with a remote boiler, so I have hot water piped into my home, the propane boiler never runs during the winter, so I have virtually no infiltrating cold air leaking into my house.. I can really feel the difference when I let the in-house propane boiler run, and put a draw on the house. Cold drafts everywhere.. Something to think about...

Greg L

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Greg, I forgot to mention that my home is about 18 years new, well insulated and I have vaulted ceilings in the main part of the house, not the bedrooms/garage. I do have attic truss so that means I have about 4' in the attic. Still I think it will cost me around 400.00 for the pipe, and I'm still not sure which way I will go with the stove. Stoker or Handfeed, kinda leaning towards the stoker as long as the fan for the blower isn't to annoying. Tim

Hi Tim, the stoker and circulation fan can be annoying, especially if this is the 'TV room' or entertainment room. Even a quiet fan is annoying if the TV is competing with the sound from the fan.

I'd go to a showroom and have a demo run of a stoker stove to see if you think it is annoying.

$400 isn't that much for the SS, and if you can place the stove and pipe more central to the room it will work better too.

One thing to think about with the stoker vs Hitzer debate. A stoker stove can be turned down to about 5-10K BTU, thats pretty low. A stove like a Hitzer can only be turned down as low as you can reduce the air to the full firebox, too low and the fire goes out. But there is no effective way to reduce the size of the fire. With a stoker, when you turn it down, it can keep burning with a very small fire area. About 1" deep by 6" wide, just a ribbon of burning coal. Then within about 15-20 minutes you can with the turn of a knob, have a full size fire going, about 7" deep by 6" wide.

So if your home is well insulated, you may find that the minimum fire in a Hitzer stove is too much and will make your house uncomfortably hot unless the weather is very cold. The Hitzer is a great stove, and I highly recommend them. But Stoker stoves have their advantages, especially in well insulated homes.

Greg L.

Where in upstate NY are you?? Maybe one of the forum members is nearby and can offer a 'listen' to a stoker stove with fans running...

Greg L

Greg, I'm just south of Syracuse in a little town called Otisco. I also forgot to mention that yes I do have a basement. I have listened to the Stokers and they can be a little noisey. There is a place near buy that sells coal and the stoves too. He has both the Keystoker and all of the Hitzers, some Harmon, Reddings, some Alaska's etc. The guy that sells the stoves has had a Stoker burning all summer long at idle. He has it setup on a Coaltroll (I think that's what its called) system. The guys who came up with that control live in a town near by . I would also get that control, its cheap enough if you order it on your new stove. But I haven't rulled out the Hitzer 354 either. Especially if I go with the metal chimney and the stove in the center of the house. If I go with the stove on the end and masonary chimney I will probably go with the Stoker for sure. I want to add that I can get a Stoker 65 from my daughter, as she doesn't use it. Tim

OK, After some thought here, I'm leaning on getting my daughters Stoker 65 and putting up a masonary chimney. I'm going to get the stoker this weekend and see if it needs anything. I will go through it clean it etc. Then I will get the materials for the chimney.