Antique Stove Efficiency

You don't have to worry about the doors being leaky. These stoves had the doors and fittings carefully machined to fit perfectly and make for an airtight seal. The only thing that could ruin the seal is if the doors are warped from mis-use. But, Mr. Doug wouldn't have sold you a stove with warped doors.

Be sure to let us see it when you get it installed and ready to go.

Hey Scott:
How is your Geneva Oak working out? I'm curious to hear how you are doing with it.

Yeah I'd like to know if that beauty heats as well as it looks.I've been thinking about replacing my ornate(ulefos) wood stove with something like that.
DON

Wsherrick, So far we have only used the stove burning wood. We have lots of free wood so I have not bought any coal yet. We are very happy with one small problem. The stove is very leaky on the air intake side of things. You cannot control the fire with the air vent controls. It will overfire and burn out of control. However, the flue damper controls the stove very nicely. It is really the main control. You just cant shut it too fast or smoke comes out of all the doors, vents, cook plate, seams etc. It burns about 3 hours on a full load of wood. (about 5 splits) and throws tons of heat. It heats our 3000 square feet with cathedral ceilings beautifully. We have not used a drop of oil and it keeps the house 72 degrees. We are very happy with the performance. to tell you of the problem I will give you a copy of a post I posted on the hearth forum below so I don't have to re type all over again. Other than this problem we are very happy.

This weekend we had a big problem with stove. The house just completely fills with smoke every time we had a big wind gust. It was a very windy and gusty weekend. Up until now the stove and set up has performed wonderfully. We have been running it for about a month now with no problems . Here are some facts about the set up.
-When the wind blew hard (gust) the smoke would just bellow out of all the leaky doors, air vents , cook plate etc. Just filled the house. Happened even after the stove was burning at 500 degrees for hours so it was a warm system
- 1904 old smoke dragon. Not real air tight but controlled nicely with a flue damper.
-15 foot interior masonry chimney with an 8x 8 clay tile liner, interior chimney
- Granite chimney cap with about 8 x 15 inch openings (stacked half bricks on corners) on all 4 sides.
- Chimney meets the 10 - 2 - 3 rule and is completely code compliant
- Everything is brand new (except restored stove)
- No trees withing 100ft, roof is a 5 pitch (with a 12 pitch roof nearby and behind)
- We have the same problem with our open fireplace (different chimney same side of house) and have extended the chimney 3 feet taller than the 10- 2- 3 rule and it did not work

Has anyone ever had this problem and solved it ?Does the Vacu stack or the wind directional caps work that Craig suggested in another thread? Anybody have a design for a home made or custom cap I can fabricate. ( I could make anything)? Any suggestions. Thanks in advance for the help

i've seen this happen with low chimneys/chimneys with chimney caps of any kind. I've never seen it happen on chimneys w/out caps that were the proper height, interior chimneys. this leads me to think that your granite cap may have something to do with it; does the fireplace chimney have any kind of a cap on it?? if so this may be the problem.

On our fireplace we did not have a cap at all. We extended it another 3 feet higher and it still happened. We are about 5 feet higher now than the roof measured 8 feet away. This is now 3 feet higher than the 10-2-3 rule. We added the cap after that and it still happens. Same thing with the stove. Does not matter if there is a cap or not. It still happens.

Hmmm... maybe not the chimney. Maybe the wind was pulling a vacuum on the house through some other orifice. Maybe through kitchen exhaust, dryer vent or attic vent. That might be able to be confirmed by opening a door or window to present another route for the air infiltration, rather than down the chimney.

No kitch exhaust vent
Dryer vent in basement

During the wind storm I left a window open that was only a few feet from the stove. It didnt make any difference and still happened with the window open. We fought this problem in the fireplace for 10 years . Finally decided not to use it if a hint of wind outside.

I think its one of Two things. Wind causing high pressure down chimney as it comes off of trees nearby. We are surrounded by forest.

2) wind hitting nearby 2nd story roof and causeing high pressure area over chimney. I will try a wind cap like the vacu stack by ICP or the draftmaster by chimney cap design

Hopefully that works

Have you noticed which direction the wind is blowing from when the backdraft occurs or does it happen everytime the wind blows hard? I had a similar problem with my chimney. It had a terrible draft and when the wind blew from the West it would backdraft into the house.
When I put the stove in I ran a flexible stainless liner from the stove to the roof. Now there is no more problems with the draft and no more backdrafting. Perhaps this may be the most practical and least expensive option for you.
BTW if you think that stove is belting out the heat now while you are burning wood. Just wait till you put about 40 pounds of coal in it

Wow, Nice Stove! I have a Round Oak in my man cave studio in the garage and have just burned wood in it for the most part for about 8 years now. It does crank out the heat even in a very drafty garage. This is a well designed stove overall and I will tend to start the fire with the bottom ash door damper wide open, as well as the feed door damper. As the fire gets established then I'll close both dampers almost all the way except for a slight crack and it's good to go from there burning a nice hot fire. When I get ready to shut down for the night, and there is a nice bed of coals in it I'll load it up with the overnighter logs and close it up tight.

Maybe I have just been lucky but I have never had any issues with smoke coming inside. I live on the top of the hill with some very aggressive winds during the Winter and it has not ever cause the stove to smoke like you have described it. So, the good news is, I do not believe this is because of the stove not being airtight, etc. I think it must be something in the way the chimney pipe setup. Maybe a baro damper set correctly will help with it. This is the right place on the internet to learn how to figure it out so good luck luck finding out the cause. It's a really sweet stove with a ton of class, so it's worth it.

I have just begun learning how to use anthracite in it myself so I can't help too much right now, but the potential when I bought a coupleof bags a year ago to try out convinced me coal was the way to go for inside my house. I'd say don't sweat it and just burn wood until you can find the source for some of the good stuff, then fill a nice big bin.

wsherrick wrote:You don't have to worry about the doors being leaky. These stoves had the doors and fittings carefully machined to fit perfectly and make for an airtight seal. The only thing that could ruin the seal is if the doors are warped from mis-use. But, Mr. Doug wouldn't have sold you a stove with warped doors.

Be sure to let us see it when you get it installed and ready to go.

this is an old thread but worth reviving, the doors on an antique stove are well machined, but they are not airtight. The only way to make a stove airtight, is using gaskets, even then it sometimes will leak. When a heavy draft begins pulling on the stove from the chimney, these tiny cracks only a few thousandths in size, will begin to pull air. The old stoves were very efficient, for their time. The better brands of today's modern stoves are a little more efficient yet. I have a friend who is an businessman, owns a construction co., and just build a new home 2300 square feet. He put a modern coal jet boiler it, it heats the entire home, and the hot water, for $4 a day using small sized coal he pours into a hopper. One 5 gallon pail a day.

one issue with these larger older stoves, they have a huge firepot typically, and that means a large load batch of coal each time filling it. On the size of the firepot alone, they will sometimes burn 2x what a modern, smaller, more efficient stove will burn- and the new stoves have electric fans in them, with heat exchangers, and many don't need a flue pipe damper or baro damper anymore.

just something to think about...

scottf wrote:Wsherrick, So far we have only used the stove burning wood. We have lots of free wood so I have not bought any coal yet. We are very happy with one small problem. The stove is very leaky on the air intake side of things. You cannot control the fire with the air vent controls. It will overfire and burn out of control. However, the flue damper controls the stove very nicely. It is really the main control. You just cant shut it too fast or smoke comes out of all the doors, vents, cook plate, seams etc. It burns about 3 hours on a full load of wood. (about 5 splits) and throws tons of heat. It heats our 3000 square feet with cathedral ceilings beautifully. We have not used a drop of oil and it keeps the house 72 degrees. We are very happy with the performance. to tell you of the problem I will give you a copy of a post I posted on the hearth forum below so I don't have to re type all over again. Other than this problem we are very happy.

This weekend we had a big problem with stove. The house just completely fills with smoke every time we had a big wind gust. It was a very windy and gusty weekend. Up until now the stove and set up has performed wonderfully. We have been running it for about a month now with no problems . Here are some facts about the set up.
-When the wind blew hard (gust) the smoke would just bellow out of all the leaky doors, air vents , cook plate etc. Just filled the house. Happened even after the stove was burning at 500 degrees for hours so it was a warm system
- 1904 old smoke dragon. Not real air tight but controlled nicely with a flue damper.
-15 foot interior masonry chimney with an 8x 8 clay tile liner, interior chimney
- Granite chimney cap with about 8 x 15 inch openings (stacked half bricks on corners) on all 4 sides.
- Chimney meets the 10 - 2 - 3 rule and is completely code compliant
- Everything is brand new (except restored stove)
- No trees withing 100ft, roof is a 5 pitch (with a 12 pitch roof nearby and behind)
- We have the same problem with our open fireplace (different chimney same side of house) and have extended the chimney 3 feet taller than the 10- 2- 3 rule and it did not work

Has anyone ever had this problem and solved it ?Does the Vacu stack or the wind directional caps work that Craig suggested in another thread? Anybody have a design for a home made or custom cap I can fabricate. ( I could make anything)? Any suggestions. Thanks in advance for the help

this is typically the type of problem you will have, when you close the manual flue pipe damper, and the outside barometric conditions also reduce the chimney draft. If the fire is big enough, the smoke will look for another way out of the stove, i.e. around the doors, glass, auxiliary draft controls in the door, etc. This why a manual flue pipe damper can be dangerous with a coal stove ! If this was coal gas and backed up into your house at night while you were sleeping, and CO detectors were not working or not installed, guess what, you may not wake up, the gases can cause death. That's one reason why I'd recommend a new stove like a Harman I with internal baffling and no flue pipe damper or baro damper. Then the worst that can happen, is the stove goes out from lack of draft.

A stove pipe damper is something you have to be very precise and careful with. If you shut the stove pipe damper completely, and it has no center hole in the damper valve, or around the edges is built up with creosote, and it makes a complete seal, it's no different than pounding a potato up the exhaust pipe of a car. The gases from the fire, be it wood or coal, will seek another exit. The old stoves not being fully airtight or gasketed, will exacerbate this problem, giving a lot of places for it to leak out.

coalcracker wrote:

wsherrick wrote:You don't have to worry about the doors being leaky. These stoves had the doors and fittings carefully machined to fit perfectly and make for an airtight seal. The only thing that could ruin the seal is if the doors are warped from mis-use. But, Mr. Doug wouldn't have sold you a stove with warped doors.

Be sure to let us see it when you get it installed and ready to go.

this is an old thread but worth reviving, the doors on an antique stove are well machined, but they are not airtight. The only way to make a stove airtight, is using gaskets, even then it sometimes will leak. When a heavy draft begins pulling on the stove from the chimney, these tiny cracks only a few thousandths in size, will begin to pull air. The old stoves were very efficient, for their time. The better brands of today's modern stoves are a little more efficient yet. I have a friend who is an businessman, owns a construction co., and just build a new home 2300 square feet. He put a modern coal jet boiler it, it heats the entire home, and the hot water, for $4 a day using small sized coal he pours into a hopper. One 5 gallon pail a day.

one issue with these larger older stoves, they have a huge firepot typically, and that means a large load batch of coal each time filling it. On the size of the firepot alone, they will sometimes burn 2x what a modern, smaller, more efficient stove will burn- and the new stoves have electric fans in them, with heat exchangers, and many don't need a flue pipe damper or baro damper anymore.

just something to think about...

I hate to tell you but the doors on my Glenwood are absolutely air tight. As far as efficiency goes, no modern stove can touch a base burner when it comes to efficiency. There is no comparison to the two.

recirculating exhaust smoke from stoves- this is not a 20th century idea, it's actually an 18th century idea. Ben Franklin tried it with fireplaces in the 1700's and was marginally successful. It does work to a degree, IF the stove or fireplace is burning quite briskly, to keep the chimney and circuit path hot, and draft pressure and velocity high. At lower burning levels, it doesn't work so well, leading to the smoke backing up into the room. Here's Franklin's patent idea, and he actually read up and copied this idea, from a previous one, so this has been around a long, long time- since the early 1600's. All a baseheater coal stove does, is take this principal and apply it to a free standing coal stove, and it does have drawbacks.

I have a relative with a coal/wood stove that has the exit pipe at a slight downward angle to the wall. That stove has the poorest draft I've ever seen on any stove in my life. He has good firewood burning performance, but lousy coal burning performance, the stove just doesn't have enough draft. The rule of thumb for flue pipes is minimum a few degrees upward angle over any horizontal run. A baseburner or Franklin stove makes the smoke go DOWN, which it inherently doens't want to do. If you use a recirculating type stove, best have a chimney with a LOT of draft. The last thing you want to do with one of these, is CLOSE THE FLUE PIPE DAMPER- now you're asking for trouble. It can then cool down and backdraft into the room.



here are the problems one may encounter with an antique stove or fireplace, using a recirculating design, once that smoke cools enough, the draft falls off and backdraft will occur, i.e. smoke into the room.

https://en.wikipedia.org/wiki/Franklin_stove#Design

Design[edit]The height of the stove was about 30 inches tall with a box shape. The front side was open, except for a decorative panel in the upper part of the box. The back of the box was to be placed a few inches away from the flue, or chimney. On the bottom panel there were several holes to allow the smoke to escape; these were connected to the chimney. These panels were bolted together with iron screws through pre-cast ears.[19] Inside there was a small thin rectangle prism that would force the smoke into the holes. The plates were all made from iron.[citation needed]

Franklin's stove sold poorly.[20] The problem lay with the inverted siphon: the smoke had to pass through a cold flue (which was set in the floor) before the smoke could enter the chimney; consequently, the smoke cooled too much and the stove did not have a good draft.[21] The inverted siphon would operate properly only if the fire burned constantly, so that the temperature in the flue was high enough to produce a draft.

Inverted siphons in fireplaces[edit]Some early experimenters reasoned that if a fire in a fireplace were connected by a U-shaped duct to the chimney, the hot gases ascending through the chimney would draw the fire's smoke and fumes first downwards through one leg of the U and then upwards through the other leg and the chimney. This was what Franklin called an "aerial syphon" or "syphon revers'd".[8] This inverted siphon was used to draw the fire's hot fumes up the front and down the back of the Franklin stove's hollow baffle, in order to extract as much heat as possible from the fumes.

The earliest known example of such an inverted siphon was the 1618 fireplace of Franz Kessler.[9] The fire burned in a ceramic box. Inside the box and behind the fire was a baffle. The baffle forced the fire's fumes to descend behind the baffle before exiting to the chimney. The intention was to extract as much heat as possible from the fumes by extending the path that the fumes had to follow before they reached the chimney.

The 1678 fireplace of Prince Rupert (1619–1682) also included an inverted siphon. Rupert placed a hanging iron door between the fire grate and the chimney. In order to exit through the chimney, the fire's fumes and smoke first had to descend below the edge of the door before rising through the chimney.[10]

Another early example of an inverted siphon was a stove that was exhibited in 1686 at a fair in St. Germains, France. Its inventor, André Dalesme (1643–1727), called it a smokeless stove (furnus acapnos). The stove consisted of an iron bowl in which the fuel was burned. A pipe extended from the bowl's bottom and then upwards into a chimney. Shortly after starting a fire in the bowl, hot air would begin to rise through the pipe and then up the chimney; this created a downward draft through the bowl, which drew the fire and its fumes down into the bowl. Once the draft was initiated, it was self-sustaining as long as the fire burned.[11] Dalesme's stove could burn wood, incense, and even "coal steept in cats-piss" yet produce very little smoke or smell.[12][13] These results showed that fires could be used inside a room, without filling the house with smoke.

Franklin's stove contained a baffle directly behind the fire, which forced the fire's fumes to flow downward before they reached the chimney. This required a U-shaped duct in the floor behind the stove, so that the fumes could flow from the stove into the chimney. Thus Franklin's stove incorporated an inverted siphon.

wsherrick wrote:

coalcracker wrote: this is an old thread but worth reviving, the doors on an antique stove are well machined, but they are not airtight. The only way to make a stove airtight, is using gaskets, even then it sometimes will leak. When a heavy draft begins pulling on the stove from the chimney, these tiny cracks only a few thousandths in size, will begin to pull air. The old stoves were very efficient, for their time. The better brands of today's modern stoves are a little more efficient yet. I have a friend who is an businessman, owns a construction co., and just build a new home 2300 square feet. He put a modern coal jet boiler it, it heats the entire home, and the hot water, for $4 a day using small sized coal he pours into a hopper. One 5 gallon pail a day.

one issue with these larger older stoves, they have a huge firepot typically, and that means a large load batch of coal each time filling it. On the size of the firepot alone, they will sometimes burn 2x what a modern, smaller, more efficient stove will burn- and the new stoves have electric fans in them, with heat exchangers, and many don't need a flue pipe damper or baro damper anymore.

just something to think about...

I hate to tell you but the doors on my Glenwood are absolutely air tight. As far as efficiency goes, no modern stove can touch a base burner when it comes to efficiency. There is no comparison to the two.

put 20 psi on the stove first, then see how airtight they are. If you dropped the entire stove into a lake, would it leak ? See, it's not really airtight. What you are saying would mean a cylinder head on a car wouldn't need a head gasket, if it was machined flat. Not true. Add pressure and they leak.

If new stoves didn't need gaskets, they would not be there. They'd save tons of money on gasket material. They put gaskets on, because it's a vast improvement in sealing.

Your stove relies on a strong draft, to make it not leak, by sucking in on any door cracks, rather than pushing out. The reason people have backdraft problems with these baseheaters and recirculating antique stoves, is when they dampen them off, and close the stove pipe damper, the chimney cools down so much, the fire loses it's draft, and starts backdrafting into the room. Just like the original Franklin stove did. They are a good design but best burned briskly and not with a fully closed flue pipe damper.

I have a similar Lehigh Oak 18 stove, that I fully disassembled and re-firebricked. Those stoves are nowhere near as airtight, as a new Harman, etc. No comparison in efficiency either. The firepots on the old stoves are too large. To make an analogy, if you have a 500 cubic inch Cadillac vintage V8 from 1970, you can put a 2bbl carburetor on it, and rave about efficiency and how well it runs. It "may" get 14 mpg on a good day- simply because it's so huge, it takes a lot of fuel to fill all that cubic inches. Even idling is still burning a lot.

It will never be as efficient as a new Gen III GM V6 with fuel injection that gets 30 mpg highway, because it's only 231 cubic inches, half the size, and has all kinds of high tech fuel management on it.

If you have a big space to heat like a 4000 square foot house, then yes that would be the ticket, the big stove. Then it will really shine.