He built his own furnace and now he has problems

I built my own wood furnace and I have a question concerning the chimney I need for proper function.  The furnace I built typically exhausts the smoke between 250 and 300  degrees F.  Although the smoke normally travels through a system of heat exchangers, for tending the fire there is a by-pass baffle that lets the smoke directly enter the flue pipe above and behind the feed door.  The  flue pipe is 8" diameter and the door is 14" x 21", resulting in a ratio of  6:1 for door area to flue area.

There are no restriction or bends that  the smoke must make to enter the flue with the by-pass open.  I currently have the stove connected  by 2 feet of 8 inch pipe and two 90 degree elbows to a masonry chimney that has an  8" square flue. From inlet to outlet the chimney is about 20' tall.  The chimney is plenty high enough  above the roof line, and there are no hills or trees to the west of the chimney.  The house is an old leaky farmhouse, so there is no problem  with negative pressures inside the house. Most of the chimney is inside  the house.  I looked up the chimney with the aid of a mirror and there is no blockage.

The stove burns fine, but I can not tend the fire without a great deal of smoke entering the basement.  In fact, I can't open the door more than a few inches before smoke enters the house.  There is less than .02" of water column vacuum in the chimney.  I measured the temperature of the smoke exiting the chimney and it was 125 degrees F.

Would an 8 inch insulated stainless steel chimney take care of my problem?  I know that a round flue draws better than a square flue of the same area,  and by not cooling the smoke so much in the chimney,  I'm sure to get  more draw.  I don't want to spend the money on a new chimney if it won't  solve my smoking problem.  I was hoping you could make some suggestions.

Tony

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Tony,

I think the problem is that your door is too large, you have too many restrictions in the venting system, and your temperatures are too low.  With a smaller door, say 12 x 12 (which is all that is really necessary), you might get away with two flue pipe elbows and another 90 degree change of direction at the chimney base. Alternatively, you might get away with a big door if you had a perfectly straight system from the flue outlet up.  But the combination you have is guaranteed to spill smoke when the door is opened.  Also, with draft of only 0.02" and a flue gas temperature of only 125 F almost any system would spill.

Here are some suggestions, starting with the cheapest and easiest things to try:

• try starting your fires top down so you don't have to mess with the fire so much at start up.
• try to get your flue gas temperature up higher; good systems need at least 200 F and 0.05 draft to limit spillage; you probably need double that considering your other problems.
• replace the two 90 degree flue pipe elbows with two 45 degree elbows to eliminate the horizontal run and reduce restriction
• since you built this thing yourself, you could modify the door to reduce its size (a lot)
• your 8 x 8 tile chimney is probably only 6 1/4 x 6 1/4 inside which is very marginal for such a large door opening; you could consider having a sweep or installer remove the clay liner and install a 7" stainless steel liner

John

 

How to heat a large L-shaped bungalow

There was a brief mention of Tarm boilers as being the only boiler/furnace to match the efficiency and emissions of wood stoves. Is this still the case, and if so, how does one find more information on this brand? Also, do you know anything about Charmaster? They claim to have a high-efficiency furnace design that burns the hot gases. The problem I have with all these manufacturer's claims is that they don't give specifications for what high-efficiency means, so I don't know how to compare it to a good stove. I'm also concerned about the emissions and again, no one publishes figures for their products.

By the way, the reason we ruled out a stove is that our house is a 1 story on an L-shaped plan and is 2500 sq. feet, with a lot of hallways and doors, so there doesn't seem to be a good place to put a stove. Furthermore, David thinks a furnace in the basement will help dry out the large unfinished basement (which I hope someday to use for yoga classes) and keep the floors warm on the main level. The house already has 2 electric furnaces with heatpumps (noisy, inefficient things, don't know why anyone would put them into a house in central Ohio); we would connect a furnace to the existing ductwork and also pre-heat our hot water which is also quite expensive and inefficient.

Any other suggestions for heating this space efficiently will be greatly appreciated. Janis

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Hi Janis,

You wrote:

They claim to have a high-efficiency furnace design that burns the hot gases. The problem I have with all these manufacturer's claims is that they don't give specifications for what high-efficiency means, so I don't know how to compare it to a good stove.

Exactly, which is why we think all wood burning equipment, including fireplaces and furnaces, should be regulated under the EPA certification program. If you check the promotional literature put out by manufacturers of EPA certified stoves and fireplaces you will see very little hype about combustion systems with made-up names. They concentrate on other features that are a lot harder get away with lying about. Fortunately, there are now several wood furnaces that have EPA emissions certification.

I've heard of Charmaster, but I don't think they have an EPA certified product at this point.

John

 

Combination wood/gas furnace??

My wife and I are building a new 2000 sq. ft. home this spring.  We are thinking about installing a dual fuel heating system.  We want thermostatically controlled forced air heat.  This system will use LPG (Propane) as well as wood.  We would not want a pellet stove as the home is on forty acres of hardwoods that need thinning badly.  We figured we could cut and split our own firewood and use the LPG when necessary only.   Is there such a system out there?

Marty & Suzanne

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Hi Marty and Suzanne,

I don't know of a combination wood/gas furnace.  In fact, in Canada such combinations have been deemed incompatible by safety code committees.  Even if you select separate furnaces and have them sharing the same ductwork (which I think is the only viable option) do not attempt to vent them through the same chimney.  Gas and wood venting requirements are not compatible at all.

Are you aware that a well-constructed 2000 sq. ft. house can be heated effectively with a single wood stove or heat producing fireplace?  These are much more efficient than most furnaces, cleaner burning and you get the bonus of a spectacular fire to watch all winter long.

John

 

Wood burning to heat several rooms

I am looking for a fireplace design that will send hot air to several rooms as well as have a nice living room view of the fire burning in a typical fireplace. I have seen something like this on THIS OLD HOUSE or one of Bob Villa's programs. Can you lead me to such a product? Thanks!

---

There are only a few fireplaces like this: Security BIS II, RSF series of fireplaces, Regency WarmHearth, Fireplace Xtrordinare, Vermont Castings WinterWarm are about it. Check with the specialty fireplace shops in your area. They will carry one or more of these.

John

 

Do central systems get a bum rap?

I know this website is about woodstoves and fireplaces but I think central wood heating is getting a bum rap from some of the writers.  I have a Tarm boiler and it is very efficient and very clean ( 1 gram emissions per hour ).  Not all central heaters are dirty and wasteful.

Ross

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Hi Ross,

I agree completely with your assessment of our site and with the frustration I sense regarding the treatment of central heating systems.  The fact is that I started my wood burning career in a wood furnace factory and was a true believer in central heating for several years.  You are quite right that not all central heaters are low-tech and that the Tarm is a fine example of what is possible.  The Tarm is not EPA certified but there are now some forced-air wood furnaces and outdoor boilers that are emissions certified.

The other problem is that the installation of central heating systems is complex and they have electric control systems that must be installed right or the unit will overheat and be hazardous. Some people might be able to self-install them, but I think they would be the rare exception. Most experienced wood heat retailers don't sell or install central heaters.

We don't particularly want to be seen as promoting just stoves and efficient fireplaces.  Our mandate is to promote responsible wood burning, not just a couple of classes of appliance.

John

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Ross responds:

John, you are not the only one frustrated.  I'm a large animal veterinarian in northeastern Wisconsin.  I spend my day working with farmers - one quarter of whom still heat with wood.  When I tell them about my Tarm I get one of three responses.

• Hey, that sounds good.  Where is the nearest dealer?
• Hey, that sounds good.  When my current furnace wears out I'll look into that.  Where is the nearest dealer?
• If I knew about them earlier I wouldn't have bought that XXX!!! outdoor wood boiler. Where is the nearest dealer?

I have to tell them, of course, that there is no nearest dealer and they would have to order them from the distributor and then find a qualified installer.  At that point their interest usually ends.  Boilers are expensive units and with past low sales. Central furnace and boiler manufacturers seem unable to maintain a dealer network.  Now that fuel prices are up more units could be sold but they don't have the network in place to do so. Most people have never heard about central heating so never consider getting one. Everyone has heard of or seen an outdoor wood boiler so that is what ends up getting bought. This is a Catch 22.

Ross

Where can I find stove ratings?

I realize you are constrained from offering advice on stove selection. It would be really helpful if you could offer sites that provide comparisons of wood stove efficiencies, emissions, general utility. If there are any, I would hope that you would know of them. I have read your advice to talk to 2 or 3 salesmen and find that it would be helpful to know more, and from a relatively unbiased source. I'd appreciate your thoughts.

Steve, Alaska

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Steve,

As far as we know there is no rating of stoves that we consider reliable enough to recommend. The problem is that few people have experienced enough different brands and models to be able to say which is better.

To illustrate the problem, I was just yesterday reviewing a long series of comments about people's experiences with wood heating equipment posted at Mother Earth News magazine's web site.Notice that people tended to really like the stove they used, whether it was an elegant, expensive Vermont Castings or a 1975 Fisher Mama Bear. People tend to like the stove they have, so how relevant is their opinion to someone looking for a new stove?

You'll also find stove reviews at HearthNet, but you'll see the same problem. Also, lots of people connect good stoves to lousy chimneys, then blame the stove for poor performance. Or they burn wet wood in a good stove, and so on.

Here is EPA's list of certified wood stoves. But don't be distracted by slight differences in emissions performance. Note that the efficiency numbers are meaningless.

Our article on the subject says most of what we have to say. Pick the dealer you like first, then buy the stove they recommend. The best dealers almost always carry good stoves.

Two final thoughts. First, there are plenty of good stoves on the market to choose from. You could pick one of a dozen different stoves and be perfectly happy with it. Second, there is no 'best stove' on the market, just the stove that suits you the best.

John, Posted January 2010

 

Does a fan increase stove efficiency?

Great site! Here's something I've been puzzling over. How much difference does having a fan blowing across the stove make with regard to it's heat delivery efficiency? I have a "high velocity" fan on it's lowest setting blowing across the stove pretty much all the time, and I've been wondering how much this increases the efficiency of the stove. Thanks, Mac.

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Hi Mac,

I don't use a fan of any kind and I don't promote them. There hasn't been much independent research on the efficiency of fan use, but many years ago I do recall one obscure study that found only a very slight difference in efficiency when the fan was used, and this was on a fireplace insert with small air circulation passages around the entire firebox.

I think the effect of stove fans is mostly psychological. If you could see air flow, you would see a huge plume of warm air flowing towards the ceiling from your stove. It would then flow down the far walls, across the floor and back to the stove. That convection flow of air, while it is gentle, is probably moving much more air than the fan, and it costs no electricity to run it. I suppose a fan might be useful to aggressively mix the air if a room had cold floors, but I can't think of another advantage.

Stove manufacturers like to sell accessory fans for their stoves because it runs the price up quite a bit. A retailer friend of mine likes to tell customers who ask about efficiency boosts from fans that 'you'll get the same effect if you let me tape your $200 to the back of the stove'.

John, Posted January, 2005

 

Do wood stoves dry out houses in winter?

My wife and I are thinking of switching to a woodstove in our log house but I'm concerned about the inside of the house becoming too dry. I've heard stories about people with wood stoves whose furniture won't stay together and the woodwork splitting. A childhood friend's father used to put a pot of water on top of the woodstove to keep the air humidified. What's the real truth?

Cliff

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Hi Cliff,

Wood stoves are not specifically implicated, but do exhaust air from the house and this air must be replaced with air from outdoors, which in cold winter weather, is dry. Hence the theory that wood stoves dry out houses. Wood stoves are no different from oil or gas furnaces or any other device that removes air from the house. But a wood stove uses very little air; about the same amount as an inefficient bathroom fan. Compared to baseboard electric systems, yes they do contribute to lowering humidity, but not compared to all other options.

The real cause of low winter humidity in houses is leakiness of the house. Here's proof - new, tightly constructed houses need active ventilation systems in winter to control the build up of humidity produced by cooking, washing and breathing. Without active ventilation, the windows of a tight new house would mist up and run with condensed water vapor.

So, in old houses we humidify, and in new houses we dehumidify. All this has little to do with the heating system, except that a wood stove in a house does constitute part of the ventilation system. If you want higher humidity in your house in winter, spend some time and money on weatherization. On the other hand, there is no way you will ever get a log house tight enough to need active ventilation to control moisture.

John

 

I want to build my own wood stove

I am interested in building my own wood stove. I have been out pricing various brands. I have found that the manufacturers are rather proud of their work (expensive). So, I figure I can build one, as I work at a machine/fabrication shop. Do you know of anywhere where I can find some plans for a stove?

---

Here is the advice I give people who want to build their own wood stove: DON'T EVEN THINK ABOUT IT! And here is why.

You can't burn wood cleanly and efficiently without a good combustion system, and you can't design and build a one-off combustion system that is any good. One of the reasons why good wood stoves cost at least $1000 is because it took a lot of practice, trial and error and bucket loads of money to get them to work properly and to pass both safety and emissions test standards.

Thirty years ago wood burning technology was crude, sort of like folk-technology and anyone with a welder could call himself a manufacturer. It is not like that any more and it is a good thing. A lot of folks got burned, both literally and financially, buying stoves built by people who didn't know what they were doing.

Consider this: I started my wood burning career over thirty years ago as a welder on the stove assembly line; I know exactly how modern wood stoves work because I've hung out with their designers and I'm a member of all the standards committees. I have a shop 100 feet from where I'm sitting where I could build one. But I wouldn't even consider building my own wood stove. I know that it would cost me way more in time and trouble than what I would pay for an 'off the shelf' stove that would be way better than I could build.

There are no plans available for a good wood stove. If I spent $100,000 developing a successful stove and have a factory building them, why would I make the plans available for anyone to build it? If you were to find stove plans, they would undoubtedly show you how to make a lousy one because no one in their right mind would suggest that a wood stove is a project for amateurs (you may be able to weld, but you're not a wood heat expert). My suspicion is that you have greatly underestimated the actual complexity buried in a good wood stove.

You have written to us looking for advice. Here is mine: Go out and buy yourself the best stove you can afford and invest your do-it-yourself time in getting your firewood in. Then sit back and enjoy the cozy beautiful fire.

John

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About John's answer . . .

(Some people associate wood burning with a sort of pioneering independence. That's fine, of course, as long as they don't put other people at risk. The problem is that misplaced self-confidence causes house fires. "Carol" sent the following message in response to the above answer. JG)

---

Someone asked where to get plans to build a wood stove. John answered like a politician or preacher. John said it's too 'complex'. (Maybe for you John). Instead of encouraging the man, (with a few caveats), John, in the tradition today's American, said: 'it's too complex, better buy one'. You're a real pioneer John!! And here's my message to John the pioneer: F.Y.!! Carol

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Another reader responds . . .

While searching for info about moisture content in wood I came across the reply from Carol about building your own stove. I would like to add to your reply about building a wood stove.

If you have a mortgage you need insurance. If you heat with wood fully or partially the insurance company needs to know and they will ask if you do heat with wood when requesting quotes. Most will send an inspector. If the wood burning system has flaws (clearances, obvious chimney problems, etc) they will ask you to either correct it or do not use it. There is a document you need to sign and mail to signify the work is completed. If you choose not to correct the problem and use the system, your insurance coverage could become void. Then the bank will be after you as you need insurance to have a mortgage. Insurance coverage approval is totally within the insurance company's control.

When we bought our home in Aug of 2002 we replaced the old stove (Red Devil) with a Regency (EPA). The inspector came in and checked the entire home, but most of his time was around our newly installed stove, like a bee around a flower. We had some clearance issues, but no show stoppers. Just an adjustment. If we kept the old stove we would not be allowed to use it as it had no labeling with the exception of the brand name. I am not alone in this experience as I have heard from wood heating friends similar stories. The insurance companies will probably get stricter as time goes on as the insurance industry is not doing well these days and are trying to keep riskier polices off the books.

So I say to Carol, building your own wood stove to heat your home is not a direction to choose. Maybe to build one to heat an ice fishing hut or garage to take the chill off and one must be very cautious still, but not to heat your home because you would be putting a great deal at risk. John's advice is indeed correct.

Stirling

 

What is the most efficient stove?

If I'm going to spend about $1200 or so for a wood burning stove, I intend to buy the most energy efficient. Can you give me a list of the most efficient?

Steve

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Steve,

Our only suggestion is to buy a stove that is EPA certified.  Here is why. There are two components of overall efficiency:

• combustion - how completely the wood burns, and
• heat transfer - how much of the energy released is transferred to the space to be heated.

EPA certification is a guaranty of good combustion efficiency, so that part of overall efficiency is covered.

Modern wood stoves don't have heat exchangers as such, but rather use the entire stove body and flue pipe as the heat transfer surface. This is because the heat output of the stove is variable, regulated by the combustion air control, and, at its lowest burn rate, an excessive amount of heat transfer surface would cause the exhaust to be too cool to provide good draft. Therefore, all EPA certified stoves run within the same band of overall efficiency (combustion and heat transfer) - about 70 percent plus or minus 10 percent.  The lowest firing rate that maintains good (flaming) combustion produces the highest overall efficiency because the slower gas flow rate through the system allows more time for heat transfer.

The stove operator has a lot of control over the net efficiency it delivers. For example, wet firewood cuts net delivered efficiency in two ways: first, boiling off the water consumes a lot of energy and second, the very large air setting needed to keep wet wood burning results a high gas flow rate that 'rinses' the heat produced into the chimney before it can be transferred to the room. Also, firewood pieces that are too large don't burn well at low firing rates and, again, demand large air settings that reduce heat transfer.

When I buy a new wood stove (which is way more often than most normal people do) efficiency is not one of my criteria because I know they are all pretty much the same and that I'm the guy in control of net delivered efficiency. I'm interested in convenience, looks and other specific preferences.

You'll find a good discussion of effective firing technique in our Tips and Techniques section.

John

 

Is Ashley still around?

I'm trying to find out if Ashley still makes wood burning heaters. I had one in my shop and lost it when the shop burned down (no, the cause of the fire was not related to the heater, it was related to sparks from the metal grinder). I'm trying to find a replacement so I can heat my shop when I build it back.

If Ashley heaters are still being made, what is their website?

Thanks, Rodney

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Rodney,

It is most likely that Ashleys are no longer made in the same manner as you are used to. We're not a commercial site so we don't keep up on all the old stoves. You could try http://www.hearth.com

However we would encourage you to look at the new EPA stoves, which we describe on our site. You could certainly do better than the Ashley.  I used one in the 70s and I can assure you that new EPA stoves will run rings around that old technology with half the wood consumption for the same heat, virtually no chimney cleaning, 90% less smoke, and so much more.

Cal

 

Advice about a 20 year old Riteway stove

I have had a Riteway 37 since the late 70's. It has been a great stove and will burn wood or coal equally well. I burn mostly wood. I recently found a brand new Riteway Catalytic converter and would like to install it. I'm not sure how to install it since the 8" pipe comes out the side of the stove. Does the converter lay on its side or should I put an elbow on the stove and mount the converter in a vertical position? Seems like a dumb question but I really want to do it right. By the way 8" stove pipe and fittings are hard to find. This summer I would like to replace all the fire brick since they are all cracked so I will be looking for them. The stove is a real tough cookie and except for some minor stuff it has been trouble free for 20+ years. Any advice would be appreciated. Thanks,

Mike

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Mike,

I had a Riteway 2000 (the other model they made, smaller than the 37) for about 3 years in the early to mid 70s, and it was a really good stove for its time. It's time is not now, however. The Riteway does not owe you much. It would be an amazing experience for you to get a new EPA certified stove which would have a nice clear view of the fire, burn 2/3 the wood, produce 90% less smoke, require virtually no chimney cleaning, take up much less room, could be installed much closer to the walls and furniture. I could go on but I won't.

The catalytic add-on unit is probably not of much use. Good catalytic units are integral with the stove's internals. I've tried a few add on cats; none of them worked. They are not usually even really recommended by the manufacturer or retailer. I'd avoid it. Keep looking and I'm sure you'll find eight inch flue pipe. It is out there. As far as I know the 37 uses standard (cheap and widely available) firebrick so that should not cost you much and be easy to do.

Cal

 

Which stove to buy?

Greetings, I just found your site by searching for "wood heat", this is the first spot the search took me and I found much more that I had hoped for. Congratulations on a great site doing a big service. Thank you.

Now, my question. I am ready to replace my wood stove, it is at least 15 years old and not efficient at all. I am heating most of a 2000 sq ft log home with an open design, the stove sits back in a stone alcove, there is enough hearth for the front of the stove to protrude several inches out of the alcove.

OK, that was the set-up, here's the question. Which is the better stove for the application: a cast stove, or sheet steel; one with a catalytic converter or without; radiant or convection? I was totally sold on a cast, catalytic unit and found some on sale. I drove into town yesterday to pick one up and the salesperson just flat out told me that I needed a sheet steel stove because it would be my main source of heat, and catalytic stoves require too much special attention. I live in a small clearing in the woods and many times the weather keeps my smoke trapped close to the ground, so I like the idea the that smoke being a clear as possible.

Any suggestions or information would be greatly appreciated.

Jeff

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Jeff,

That debate about which stove is best – cat/non-cat; radiant/convection; cast/steel – has been going on for thirty years and shows no signs of topping. And the next dealer you go to might tell you exactly the opposite.

Here at woodheat, there is no consensus on the matter. Cal heats with a catalytic cast iron stove and I heat with a steel non-cat. Both of us do fine. I'm sure that whatever stove you buy, provided it is properly sized for the application, will work fine and satisfy your heating and aesthetic objectives. There is lots of product choice and many of them are very good. We think your best resource is a good dealer with experience and a good reputation. If you start with a good EPA certified stove, then feed it properly sized and seasoned wood and run it carefully, I would be just about willing to guarantee you will never again see 'smoke trapped close to the ground'.

John

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Jeff replies:

Thank you for the information. Like many items in our consumer-based lives, it appears that the "bells and whistles" aren't nearly as important as proper use of the item itself. I will visit your site again, s'long for now.

Jeff

 

We want the most efficient stove

Do you have any information that would include emission/efficiency ratings on various brands of woodstoves? My husband and I are looking for help in choosing the most efficient wood burning stove for a home we plan to build in the foothills. Thank you,

Helen

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Helen,

EPA publishes a list of certified stoves which contains their emissions figures, but not efficiency. Actually, the list does give efficiency figures but they are just defaults; catalytic stoves are given an efficiency of 72%, non-cats are assigned an efficiency of 63% and pellet stoves are all listed as being 78% efficient. These are highly suspect figures and their continued use is no credit to EPA's supposed scientific impartiality.

I don't think EPA's list is worth getting, but you certainly should be choosing a stove that appears on the list.  If I were you, I wouldn't worry about the actual emissions and efficiency figures because all certified stoves are at least 60% efficient and most are closer to 70%.  Their emissions can't exceed 7.5 grams per hour of operation and most new stoves are down around 3 or 4 grams.  These variations are not as great as the variations you create yourself by the type of wood you burn and the way you operate the stove.

The more important thing is to find a good reliable stove/fireplace dealer who can give advice on stove sizing, location, chimney needs and so on.  Beyond that, you just need to choose a stove that fits your budget and decor objectives.

John

 

Building his own wood stove

I have a two and a half car garage that I have set up as a woodworking shop.  At present, it is not heated. I  wonder if you could give me some direction as to where I might be able to find plans to build my own woodburning stove.

Mike

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Mike,

I do not consider wood stove construction to be a do it yourself activity. I gave up doing that in the 1970s when it became apparent that woodburning technology was as complex, and in some ways more complex, than other technologies that no one would consider as do it yourself. On the other hand, you can burn wood in any steel box. If you do find plans for a wood stove, I would be surprised if the author really knows what he's talking about because if he did, he wouldn't publish plans. My advice is to buy a decent wood stove and apply your technical skills to woodworking.

John

 

In love with a Franklin stove

Hi...My husband and I just bought a gorgeous Franklin wood burning stove from an elderly neighbour for $25. I'm not sure why we bought it except that I fell in love with it the minute I saw it . . . it's so rustic!  Anyway, we heat with oil, but want to put the stove in our living room.  I am absolutely  terrified about the risk of fire though. My husband insists that we can do the installation ourselves . . . any suggestions? Also, if we did decide to go with a professional installation, any idea what it might cost?

---

Hi,

Yes, Franklin stoves are nice looking. But they are lousy wood burners.  A Franklin might be worth installing in a summer cottage, but certainly not in a main residence. The first clue is the price you paid; it's about what it is worth. How about using it just for decoration, and not attempting to actually burn wood in it? How about buying a nice set of electric logs and putting them inside?

A Franklin can be installed safely (provided it is structurally sound) using the detailed requirements of NFPA 211 in the US or CSA B365 in Canada. But the chances of someone who has never done it before using one of these codes to install an uncertified stove correctly (safely) is slim to none. At the very minimum, you need coaching from an experienced sweep or installer who knows the code intimately. It is very complex to interpret.

I would strongly recommend that you get professional advice before doing anything with the Franklin. 

John

 

Am I burning too much wood with my old stove?

I have a 2750 sq.ft ranch home with 9 ft. ceiling on the main and basement levels. I built this home myself 4 years. ago and it is built around R2000 requirements. I have a high-efficiency forced air propane and a heat recovery ventilation system. I use an old double glass door wood stove measuring 17"deep x 24" high x 32"wide in my basement.

I use a lot of wood in my attempt to keep my furnace from kicking in. This heating season I have used approximately 7 cords of wood [4 ft.x 8 ft. piles]. Is this too much wood and is my stove inefficient? I cut my own wood from a local bush lot that was logged and pay $5 a cord. The wood is ash, oak, maple. I live southwestern Ontario.

Perry

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Perry,

All I can say is its a good thing you don't pay much for the wood. I do have some suggestions for how you might cut your wood consumption and some things you might look into. For comparison, my 1500 sq ft house uses just about three full cords for the whole winter. I don't think you should need more than double that because your's sounds more energy efficient.

Also, your stove is all wrong, both in terms of shape and age. It is probably delivering something like 45 - 55 % efficiency under ideal conditions. However, because you are heating such a large space from the basement, your firing rate, and therefore flue gas heat losses are probably very high. So, your delivered efficiency is probably less than that - perhaps 40%. For comparison, a new EPA certified stove delivers something more like 70% efficiency, if it is run in the right heat output range.

Unless you spend most of your time there, heating your house from the basement is a big mistake, as I have been telling people for 30 years. You end up with high air temperatures and really high heat loss from the (usually) concrete floor and less than perfectly insulated walls. Transferring heat from basement to main floor is not as easy as it seems. A wood stove is a space heater, for heating spaces, not a central furnace.

You have two options. First, you could put a wood furnace in series with your existing conventional furnace for central heating . This would work and probably cut your wood consumption while improving your family's comfort, but you would miss all the pleasures of the fire. Fortunately, there are now some EPA certified wood furnaces to choose from.

Or you could open your cheque book and buy one of the big, efficient, factory-built, EPA certified fireplaces for your living room. You can attach ducts to these and connect them to your furnace ductwork to spread the heat around your home. Some of these fireplaces are powerful whole house heaters (eg RSF Opel, Regency WarmHearth and Security BIS II, Fireplace Extraordinare). Picture yourself in your living room in front of this gorgeous fire, knowing that its heating the house and saving you money at the same time. This, to me, is what wood heating is all about. If you don't want to lug wood upstairs, buy yourself a wood waiter, a little electric elevator designed just for the purpose. Now we are talking about a truly civilized system.

Okay, I just spent about $9,000. of your money. But look at it this way, what other expenditure that size would give you the same amount of lasting pleasure and comfort? None, I would submit.

One other thing, I found that my HRV was over-ventilating the house, since there is only me and my spouse here, so I put it on a timer. It's on for a few hours first thing in the morning and from dinner to bedtime. Made a huge difference. Mind you, if you have a lot of people around or a full time smoker, you can't do that.

John

 

Wood stove recommendations

Hello, we are ready to buy a new woodstove. we want a clean burning efficient stove with a picture window. We would prefer a stove that gives the option of top /rear venting. We are heating about 1600 sq feet, and are considering an addition. Can you help us with some suggestions. thanks

Gary

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Gary,

We don't make specific brand recommendations. Clean burning stoves are EPA certified and most  of those perform very well.  Most modern stoves have glass doors with airwash to keep it clean. The top/rear take off option is mostly available in cast iron stoves which look nice and work fine, but tend to me more expensive than welded steel. In fact that objective reduces your options to relatively few; Vermont Castings and Jotul being the main ones.

Depending on where you are and how well insulated and sealed your house is, you could need a fairly large stove. But a large stove can only perform well to heat a large area if the area is reasonably open plan, so you need to judge that. The best advice I can give is to visit two or more retailers and hear what they have to say. They can probably give you better advice than I can because they can ask you the right questions.

John

 

A pricey question; a tie breaker solution

Help, we are torn on what to do.  I have an opportunity to pick up an older Timberline dual door, 8" flue size stove.  A friend of mine prefers to send checks to the local oil company and removed this stove.  Too bad because he had a nice set up: a brick base tastefully done and the stove pipe going into an existing brick stack. I think he is crazy!

Anyway his loss my gain (possibly).  He offered the stove to me for $200, then we talked of trading up on something I have that he wants, etc.  I was very excited about this, but chose to do my own research.  My plan was to install the stove on the lower level of our raised ranch home.  We have two rooms downstairs but sometime in the next year I plan to make one big room that is 20' by about 20'.  I planned to let the heat rise and heat the upstairs.  During the extreme cold I had all intentions to burn wood at least 3 days a week, and lots of overnight burns. Could probably talk the wife into running the stove so possibly as much as 6 days. The pipe alone for the installation would be $1200.

Here is where I get confused.  A gentleman that has over 30 years experience (installed my parents Timberline insert) told me that it is a superb stove and if I could swing the cost of the pipe to go for it, or have a mason build a stack for me. Another friend has the same stove and said that the price is a steal. He has two stoves in his house and really is up on the subject. Two local retailers told  me that the stove is dirty, old technology, will run me out of the house and should be in a junk pile.  The one retailer has a great shop with Jotul stoves, etc. and appears to be very fair and honest. Another web site web master told me to go with " a new efficient stove"  but I really don't know what his stake is with his sponsors, or if that is even a fair analysis.

My wife and I stopped by his shop and priced out a Jotul OSLO F500. Looking at stoves we estimate that we need a stove to heat 900-1300 square feet so this model is right there.  The new stoves are very attractive but I am not much into spending another couple of thousand dollars if I don't have to.

Any comments suggestions are very much appreciated!!  I will use your comments to break the tie, all I know is that we will be getting a stove in the next year or so.  My last question, if we waited until the off season, do you think we would see a significant savings in the cost of a new stove if we decide to go that way.

Robert

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Robert,

We at woodheat.org get a number of letters like yours. We certainly appreciate your concern which you so well expressed. If you check our web site you'll see that we support environmentally appropriate woodburning. We would definitely vote for a new EPA certified stove. The Jotul is lovely and would be a good choice. There are lots of very good stoves on the market now. There is no standard for clean burning other than EPA.

EPA stoves will reduce smoke by up to 90%, while increasing efficiency by about 1/3, and reduce chimney cleaning to an absolute minimum in comparison with the Timberline.  Another important benefit is that the fire view on an EPA model will really be a treat. It's unlike any other fire you've seen, and of course superior to the Timberline's cast iron doors.  Many folks who change to the clean burning stoves tell us that this is a wonderful and surprising aspect of heating with wood that they hadn't considered previously.

Your placing of the stove seems to be a good one. Your plans for a new chimney and pipes will make the system work well, since as you understand you are installing a system, not just a stove. We would recommend that you use a properly sized, certified, insulated metal chimney running straight up immediately above the stove (not through the wall) and connected to the stove with a good quality certified double wall flue pipe.  This will give you the best performance; preventing smoke spillage in mild weather, while making the stove easy to start, load and accelerate.

We have no  commercial links with the industry as a nonprofit agency, so I hope that you take this in the spirit it is given.

Cal

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Robert responds:

I will take your letter as the tie breaker then!  We agree on the Jotul - what are your other favorite stoves out there that you like.  I don't want to pick up a stove and not be happy. I know you get asked a lot. Thank you again for your assistance!!!

Robert

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Robert,

Favorite stoves . . . this can cause us problems, as we try to be impartial.  I can say that there are two possible configurations for EPA stoves: catalytic and non-catalytic. Most (the vast majority) are non-cats and a few are cats. Cats will generally burn longer, and require more maintenance (in the way of parts). Non-cats are usually easier to use but do not generally burn as long as catalytics. It's like manual and auto transmissions. Some like manual, although they are more work because of higher performance, some like auto because of ease of use.  I will say I like cats, but I am in the minority around here.

Cal

A Really Large Fireplace?

I am designing a large fireplace for a hotel in North Carolina. The hearth opening is approximately 8'-0" wide x 4'-0" high. Do you have any guidelines for a fireplace this large? We have plenty of information for residential scale fireplaces, but nothing for something this large.

Thanks for your time and trouble. David

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Hi David,

No, we don't have any information on large conventional fireplaces. My only advice would be to have your liability insurance paid up because so many of these fireplaces fail to function properly. The key variable is not so much flue size and height as it is the pressure difference in that part of the hotel caused by air handlers and exhaust fans. The best insurance is to make sure that area is always pressurized relative to outdoors.

John

 

Designing a Fireplace

Hi. You have a great website. We are looking for a design for a forced air fireplace. We are building our own home/fireplace. Thanks for your help. Gina

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Hi Gina,

We don't think wood burning appliance design and construction is a do-it-yourself kind of job. I would strongly recommend that you buy a good factory-built, EPA certified fireplace and then use your own skills and creativity to design and install the facing materials and mantel that make it your own special fireplace. Leave the design of its internal workings to people and companies that have spent decades of effort getting it right.

John

 

Wood Burning Fireplace vs. Gas

We are building a new home. My husband would like to put in a wood-burning fireplace. He thinks gas fireplaces are too "fake". I can't say I disagree with him but I know gas fireplaces are more efficient, easier to use, etc.

The sales people encourage us to put in gas as well. I would like us to make an educated decision on this - do you have any suggestions? I look forward to hearing from you. Sincerely, Rachel

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Hi Rachel,

In addition to what you can read on our site about why you might want to choose wood, and suggestions about what type of wood burning fireplace to go with, here is more food for thought on the subject:

You should buy a gas fireplace if:

• you live in an urban condo or apartment
• when you look at an operating gas fireplace it doesn't look fake to you
• the thought of wood chips and ash dust near your hearth is truly scary
• you don't worry about escalating fossil fuel prices
• a broken fingernail is considered a crisis of sorts
• you prefer take-out to home cooked meals
• you don't mind emitting greenhouse gases from your hearth

You should buy a wood fireplace if:

• you grow flower gardens or a vegetable garden
• the idea of moving and stacking firewood sounds like fun
• you find the concept of self-sufficiency appealing
• getting to build a fire on the hearth is a form of compensation for the fact that summer is over
• you can't take your eyes off a natural fire
• you'd rather not suffer in the cold when the power goes off in a storm
• you like to stay in touch with the natural world

If a fireplace retailer tries to talk you into a gas fireplace, you should not buy from that retailer, particularly if you end up going with wood. Gas fireplaces are not more efficient than wood. You can buy a woodburning fireplace that delivers at least 75% net seasonal efficiency which is competitive with just about any gas fireplace.

If you decide on wood, we strongly recommend either a masonry heater or an EPA certified factory-built fireplace. If you build a conventional masonry fireplace, it is our view that you are throwing your money away and that it will probably behave badly in your new house.

John

 

Two-sided Fireplace

Hi...I reviewed the answers in your installation section...I'm not sure if your objection to Bruce the architect's design was the see-through nature of the fireplace, or the overall size, so I just wanted to check.

We are planning a cottage guest-house (that will be used in the winter) of about 500 sq. ft., and we were hoping to have a single fireplace with a glass face on the living room and another glass face on the opposite side of the fireplace, facing the bedroom. Would this have a large impact on the efficiency / safety of the fireplace?

Thank you for any information, Brenda

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Hi Brenda,

See-through fireplaces are usually troublesome when they don't have glass doors or when the doors are open because the ratio of hearth opening to chimney area is too large so they tend to spill smoke into the room. You say you intend to put glass doors on both sides, so smoke spillage may not be a big problem, but be prepared to clean the glass often, like after every fire.

There are a few factory-built, two sided fireplaces that I don't mind recommending because they have reasonable combustion features and a heat exchanger, and air-wash to keep the glass clear. One is made by RSF, but there is one or two others. You might see if you can find a dealer so you can at least have a look at them.

A conventional two-sided masonry fireplace is more likely to be a wood hog and not provide much heat. If all you want is a decorative fire without heat, you are probably at the wrong web site because, as I think we make quite clear, we don't support these for environmental reasons.

John

 

Giving up on a two-sided fireplace?

We purchased our home about three years ago and it had a beautiful see-through fireplace between the living room and dinning room. We get next to no heat from it unless you are standing right in front of it. I have tons of concerns. First, wasting firewood, wasting the conventional home heat, and wasting money. I also have environmental concerns; we are not only polluting the outside, but it frequently drafts back into living room so we are polluting the inside.

The question; is our solution only a single sided insert? I have looked online and have had no luck in finding a two sided insert. Will doors on both sides increase the efficiency enough to use this fireplace again? Or should I just give up and find a nice bouquet of fake flowers to stick in there permanently?

Mike

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Hi Mike,

You can't find a two-sided insert because there are none that are EPA certified so we can recommend them. There is no way that a manufacturer could pass EPA's emissions test with an expanse of glass on two sides of the firebox. You could put doors on both sides, but they will probably block most of the heat so there would be hardly any efficiency improvement; plus they will soot up during every fire.

Here's an idea: Put a good insert in one side and put the fake flower arrangement on the other side.

John

 

Loss of Central Heat with Use of Fireplace?

I told my friend Ann that I planned to keep my thermostat lower this winter and use my fireplace to save on utility bills. She felt I would increase my bills because of heat loss up the chimney. When there is an active fire in a fireplace will central heat be lost up the chimney? I would love to get this resolved. Ann for years has avoided using her lovely fireplace for this very notion. I grew up with a fireplace as the main heat. I never questioned this before.

Thank you, Carrie

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Hi Carrie (and Ann),

This is a long-standing argument among wood heat and energy specialists, and some who see themselves as experts have never managed to understand why net energy from conventional fireplaces is so low.

First, a clarification. When we say that a conventional fireplace can produce zero efficiency or less, we are talking about a fireplace without doors or one operated with doors open and the situation is always worse when there is a large indoor/outdoor temperature difference, i.e. when it is cold outside. If the outside temperature is only 5 or 10 degrees below room temperature, you can actually gain some heat from an open fireplace, particularly if the fireplace is massive and some of the heat is stored in the masonry.

Any air passing through the combustion and venting system that doesn't participate in the combustion reaction is called excess air; that is, air from which no oxygen reacts with the carbon and hydrogen from the wood to produce heat and light. It turns out that all combustion reactions require quite a bit of excess air, partly to produce turbulence in the chamber and partly because there is no way that all the oxygen molecules in a given volume of air can be easily reacted, so you have to provide extra. This is true for all combustion reactions, from gas and oil furnaces to cars and airplanes. Excess air is expressed as a percentage of the amount of air theoretically needed for combustion.

A good wood stove will run at low excess air levels, maybe only 160%, or 60% more than is strictly required. But that open fireplace will run 1000% or 1500% excess air or more depending on its design and how big a fire you put on and how you set the damper. Excess air kills efficiency in two ways: first it 'rinses' much of the heat produced right up the chimney and out of the house so little heat is delivered to the room, and second, the air rushing up the chimney must be replaced by outside air which must be heated up to room temperature, at a considerable energy loss.

Plus, open fireplaces don't have heat exchangers, so most of the heat you gain is radiation right off the flames. Most of the heat produced gets sucked right back up the chimney. Remember the centuries old wingback chairs? The wings are to trap the radiation from the open fire around your body and to keep the cold draft from under doors and windows that is being sucked towards the fire, off your back.

If you want to shield your household from high conventional energy costs, the most effective, economical and safe way to do it is have an EPA certified fireplace insert installed in your fireplace. You would be amazed at the performance difference and the relatively tiny amount of wood you would burn compared to the fireplace. You are probably looking at more than $3000 for a fully installed insert with a stainless steel liner to the top of the chimney, so it is a serious commitment.

I think you should try your fireplace, but I would be very surprised if it produced much useful heat, unless you live in a very warm place. Once it gets cold out, why not turn the thermostat right off, build a fire and see what happens. Most people find that the house gets cold, and quickly too.

On the other hand, if you had a fireplace with doors and a circulation chamber around the firebox with vents top and bottom to the room and you ran it with the doors closed, you might get some heat, but usually the efficiency is quite low, typically in the 20% range, compared to 60 to 70% for a good insert.

Ann was right on this one.

John

 

Insulating Above a Fireplace

I have what is hopefully a simple question. My fireplace is installed inside what is basically a triangle created by the walls of two rooms and a hallway. The walls that border the fireplace are not insulated and allow heat from the attic to enter the house in the summer and allow warm air to leave the house in the winter. When looking down from the attic one can see the fireplace and the uninsulated walls. I would like to insulate this space by placing an insulated barrier around the flue up in the attic. The flue is triple wall pipe and the required offset from the flue to flammable material is indicated by a sticker placed on the pipe. Is it safe to insulate above a fireplace like this? What are the code requirements? I live in Southeast Georgia, so the fireplace is not used that much. I am just afraid that if I insulate above the fireplace, even though there would be over 5' of clearance, that it will get too hot in the walls. Thank you.

Bryan

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Hi Bryan,

It is a good thing you sent the drawing, because I had misunderstood the location you want to put insulation.

Yes, you can go ahead and insulate that area, provided you leave the required clearance around the chimney, which is usually 2", but I can't be sure. There are standard certified components for these chimneys called attic radiation/ insulation shields, that are designed to sit in the framed joist space where the chimney passes through. These shields establish the minimum clearance and most of them are closed at the top with a sloped shape so you could actually blow insulation in without having it remain against the chimney surface. You can achieve the same thing by, for example, forming a sheet metal cylinder around the chimney to keep the insulation back. The advantage of the certified component is that it will also keep rodent nests out of the space next to the chimney. Once you are finished insulating, be sure there is no insulation material within the 2" installation clearance.

John

 

Fireplace Odors

I enjoyed your website. I will be looking at the other links for more information. The questions and answers helped but didn't specifically identify the problem with my fireplace.

I purchased a 15 year old home a few years ago. I've used the fireplace exactly 4 times with very undesirable effects.

The house is a two story home with a great room behind the garage which serves as a family room with the fireplace on the outside wall. There is a cathedral ceiling which goes up to the second floor loft ( a common design in this neighborhood). The brick/clay fireplace is on an outside wall and the brick chimney is high enough only to meet code and does not reach above the peak of the house. There are two smaller gas forced air furnaces in the basement (up & down) and they are 20 ft. away from the chimney and therefore require a vent fan that runs on the flue. Whenever I use the fireplace the house smells strongly of soot for days afterward even if I clean the ashes. It is so strong you would expect to see fire damage somewhere. Although I hadn't found your website yet I selected a reputable chimney sweep for an opinion. He seemed to be looking for some brickwork at the tune of $1,000.00 and didn't seem to offer any solution to the problem. ( The only worthwhile mumbling may have been about finishing off the smoke chamber to make is smooth.)      A heating contractor installed a fresh air vent into the basement for the furnaces but this doesn't help and the vacuum from the furnace exhaust fan actually pulls the basement door tightly closed when it turns on (so much for the fresh air intake providing the makeup air and breaking the vacuum on the house.

These contractors are well-intentioned however they are not overpowering in their engineering knowledge. Or , maybe they are trying to cover up a poor design.

Give your readers some good advice. If you build a fireplace or have a chimney in a new home put it in the center of the house where civilized man has been building it for centuries. They draft better and don't cause problems like mine. In my old house with two old converted gas boilers you could feel the draft in the flue even in the summer. The old-timers knew how to build better 80 years ago.

Do you have any suggestions for me or should I move and forget about it? My compliments to you on your web-site!

Richard

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Hi Richard,

Your analysis is correct. Have you seen our article on the evil outside chimney? And the section on outdoor air?

It sounds like you have a classic case of cold backdraft at standby complicated by some other factors. As I think you are aware, there is no sure-fire solution to the problem because it is caused by the physical relationship between the chimney and the house, which is not easily changed.

But the bottom line is that the cold backdraft can be avoided easily at the design stage, but not once the house and fireplace are built.

You could consider gutting the smoke shelf/throat damper/smoke chamber area and install a chimney top damper operated by a chain. This would reduce cold backdrafting. Or you could consider putting in a fireplace insert with a full stainless chimney liner. Neither option is a 100% certain cure, but either will usually help some. Maybe you need to keep looking for a qualified professional to help.

John

 

Outdoor Air Supply for Fireplaces

Please provide info on a fresh air damper for a masonry fireplace. Do they actually work? The idea is that they pull outside air for combustion and do not pull heated air out of the living space. The problem is that my local brick association recommends the installation of one in a new masonry fireplace although they cannot tell me where to secure one. Please inform me ASAP as I am planning a new masonry fireplace in an addition that will take place in June.

Thank You, Chris

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Hi Chris,

The real question is not what your brick association contact's opinion is about outdoor air supplies, but what are the requirements in your local building code. Many jurisdictions in North America make outdoor air supplies for fireplaces mandatory and if that is the case where you are, then you have no choice but to put one in.

I should point out, however, that mandatory outdoor air rules appearing in building codes were added because it was a widely held opinion that outdoor air made sense. See the discussion on our site about outdoor air supplies.

It turns out that the best way to prevent smoke spillage from fireplaces is to give them tight fitting doors and combustion systems that will sustain flaming combustion. It is also important that the venting system be well designed and that the pressure in the house be managed within reasonable limits.

In answer to your question, no, outdoor air supplies don't work, but you may have to put one in anyway. I don't know where to get an outdoor air kit for a masonry fireplace, but I would be surprised if a local mason couldn't tell you, since if they are mandatory, the masons must be using something.

But aside from the issue of outdoor air, our advice is NOT to build a conventional masonry fireplace. You would have much better performance and much less pollution from either a masonry heater or an EPA certified factory-built fireplace.

John

 

New Smoking Fireplace

We just built a brand new home in November. Our zero clearance wood fireplace (Heatilator) upstairs burns fine if the doors to the fireplace are closed, but if we open them smoke comes out into the living room. We were told that our home is very airtight and we need to install a hole (vent) for outside air in the fireplace side wall to equalize the air pressure into the room. The fire burns very well and we have no smoke until we open the glass doors of our fireplace.

Can anyone give me any advice on this? Thank you for your time, John

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Hi John,

Open fireplaces were fine for leaky old houses, but now that we demand draft-free comfort and low heating/cooling bills, houses have had to be built tighter, so open fireplaces should be relegated to history books. See the article on our site about open fireplaces.

Outdoor air for the fireplace is a widely promoted solution, but it doesn't work. See our section on outdoor air supplies.

My advice is to keep the doors closed. I'm a little surprised someone didn't warn you about this in advance.

John

 

Sharing Flues?

I have a woodstove in the basement connected to the same flue as our natural gas furnace. Recently my landlord installed an aluminum liner in the flue rendering my woodstove use inoperable.

I would like to tap into the 2nd flue of the chimney (from basement) that services the upstairs fireplace. What I need to know is if this is possible? I am guessing I would have to brick the upstairs chimney closed. It looks as though the ash vent at bottom of fireplace would provide enough draft but again, I'm not sure.   Any recommendations or direction I could find info would be helpful.

Thanks in advance. Dave

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Hi Dave,

Neither flues serving gas appliances or those serving fireplaces are acceptable for venting of wood stoves. In theory you could brick up the fireplace and use the flue but that is more complicated than it seems. What you really need is to talk to an experienced dealer to inspect it and advise you.

John

 

Reading between the lines of fireplace plans

In the past I have received some valuable insight on fireplaces and the best way to build the chimney (inside!)  I hope you can help me with the rest of the much needed information I need before we begin construction.  We are planning to add a room onto our two story farmhouse with a fireplace in it.  I would like to know where I could get plans to build a energy efficient one, (size wise what are my options), possibly run a gas line to it for down the road, and how do I insulate behind it since it will be fully enclosed inside the room with vinyl siding on the outside.

Kevin

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Kevin,

There are a few things about your message that make me think you are about to make a big mistake.  If the addition to are planning will be a single storey, you could create a fireplace that cold backdrafts even if you install the chimney inside. You'll find a discussion of the issue in our chimneys section.

When you install a fireplace and its chimney inside the warm part of the house, the only insulation that is necessary is the standard wall insulation.  If you are talking about making the back of the fireplace flush with the outside wall, you are setting yourself up for a bad fireplace that backdrafts and stinks.

We don't consider the construction of an effective woodburning system a do-it-yourself job.  The only masonry device that we think is worth considering is a masonry heater, and that is certainly not a job for an amateur.

Finally, we don't support the wasting of wood in fireplaces that are designed only to be used for watching the fire.  Plus, decorative fireplaces are the ones that most often fail to work properly.  My advice is to buy an efficient factory-built fireplace or have an experienced professional build a masonry heater for you. Save yourself a lot of aggravation and do the environment a favor.

John

 

The limits of long-distance diagnostics

I'm glad to find your web-site! We are having a problem only an expert might be able to solve. We are restoring a 105-year-old house and have finished (we thought) the restoration of our 5 fireplaces. However, as soon as we started a fire in our newly restored fireplace the attic fills with smoke! We installed new flues and dampers in all the chimneys, size of liners/dampers specified by flue manufacturer, and rebuilt the firebox, smoke chambers and hearths with the assistance of a mason. Still it smokes. We also installed gas lines to each in the event we decided to burn gas or use a gas starter. Our concern is number one; the smoke from the wood-burning and two; carbon monoxide or in the case we use gas the fumes from the LP gas.

Any ideas? Any help would be most appreciated!!

Deborah

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Deborah,

You have a problem that is too complicated to diagnose this way. You need to find an experienced fireplace specialist locally to inspect the systems and give advice. Check yellow pages and building contractors for leads.

You are right to be concerned about the safety of the fireplace if you just convert it to propane. When a wood fireplace spills, it is usually just an annoying smell; when gas spills it can be deadly because it doesn't smell much and it runs unattended.

John

 

Upgrading a 1913 fireplace without ruining the look

Hi, I really enjoyed your site and your discussion of open fireplaces.  I came to your site because I would like my 1913 fireplace to stop stealing heat from my house and maybe even supply some! I love my fireplace but realize I need to do something.  You suggested doors....is that all I can do?  The fireplace is arched brick and my house is charming in its craftsman style, and I really do not want cover the arch or ruin the look with a 1970's-looking "insert."

Should I have someone make doors?  Can I have a custom designed insert that won't ruin the look?  Where should I turn?  Thanks for your help. I am at a loss and getting cold. Thanks!!! Susan

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Susan,

Sorry, there is no simple answer to your dilemma. You cannot get the performance you want and retain the period look of the fireplace exactly as it is. I think you will find custom doors costly, yet unsatisfactory from a heating point of view. You don't want to attempt a custom insert; that approach would undoubtedly be very expensive and unsuccessful.

Here's what I would do. Visit some wood stove stores to find a new attractive cast iron wood stove and install it on/in the hearth and connect it to a full stainless steel chimney liner running to the top of the chimney. That way you wouldn't completely destroy the look of the fireplace because the opening would not need to be covered. Note that Ben Franklin stuck stoves in front of brick fireplaces, so a hearthmount stove is not out of place in a period setting, especially if it is an ornate cast iron model.

Good luck with it.

John

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Susan responds:

Thanks so much John! I think this is the best option I have heard so far.

Sue

 

See-Through Fireplace Design

I am an architect in Maryland trying to find information that will allow me to design a 48" wide x 40" high fireplace with a 45' chimney.  I need to offset the flue 2' to 3' between the first and second floor lines (12').  I will need to start with an offset, high-form damper and then construct a metal throat which will also be offset. At the second floor line, the flue will start (24" x 24" ).  I am assuming that an Exhausto fan will be needed to insure operation if the draw becomes a problem.  I would appreciate your providing me with your fax number so that I can send you a sketch of what I am proposing.  I also need contact telephone numbers (or fax, web page or e-mail addresses) for Exhausto, high-form damper companies (Donely, Vestal, etc.), and any other sources you can recommend.  The project this information is needed for is under construction, so time is of the essence. Thank you,Bruce

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Bruce,

The fireplace design you contemplate for your client is the antithesis  of everything we at woodheat promote.  Huge conventional fireplaces are inherently wasteful and polluting of both the indoor and outdoor air, and see-through designs tend to be the worst.  Over the course of my career I have seen many of these fireplaces cause disappointment, heartbreak and lawsuits.  When I owned a fireplace shop in the 1980s we had a policy of refusing to get involved in such fireplaces, knowing they are much more trouble than they are worth.  On the other hand, we were called in several times to help resolve the problems they create.  See the article on our site about fireplace problems.

You are right that you will need an Exhausto or similar unit to make the fireplace work at all since the basic design is incompetent on its own.  But make sure there are no other spillage-susceptible combustion systems in the house, like an atmospheric gas water heater or furnace/boiler, because they will tend to backdraft when the fireplace is operating, unless you force a large volume of make-up air in from outside.

Knowing what I know, my advice to you would be to dissuade the client from this folly that so many others have fallen victim to and if they don't agree, then run from the contract. This fireplace is a statement of ego that runs hard up against the laws of physics, and even if you can make it work and escape being sued, the environment will suffer. There are alternatives that will work, but not at the huge scale you describe. We don't promote specific products, so if you are interested you need to do some searching and talk to some fireplace specialists who earn their living by advising customers and selling products.  By the way, I typed Exhausto into a search engine and immediately came up with their web site.

John

Al wants to move heat from room to room

I am thinking of putting large (1'x3') vents at the top of the walls in my house. How can I determine if I should install a fan in them or rely on passive air movement? What kind of vents can I get that have a  feature to close the vent for zone heating? Any other ideas to spread heat to other rooms including upstairs?

Sincerely, Al

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Hi Al,
The passive transfer of heat from one part of a house to another is a tricky proposition, depending to a large extent on the characteristics of the house itself. I think the critical factor is the energy efficiency of the building envelope. That is, the individual rooms in a leaky, poorly insulated house need a lot of heat input every hour to maintain a comfortable temperature, much more than can be supplied by passive convection from another room. On the other hand, a relatively tight, well-insulated house tends to remain at a fairly even temperature throughout, even if it is being space heated from one location. So, if your house is drafty and uses a lot of heating fuel each winter, passive convection is a hopeless strategy. That is why houses built 100 years ago had wood or coal heaters in each of the key rooms.

Also, it is my experience that convection currents take a long time to get established, so if you don't plan to run your stove 24 hours a day, passive convection will never really become an effective way to move heat.

I heat my house very effectively by passive convection, but then it was designed from the start to operate that way - it is fairly energy efficient, is oriented vertically (3 floors) rather than horizontally as in a ranch style, and the stove runs constantly.

If your house is reasonably energy efficient, you shouldn't have much trouble getting heat to go upstairs. It is getting it to flow to adjacent rooms that is difficult. Another common alternative to passive convection is to run the furnace circulation fan (if you have one) on low speed continuously. This does have drawbacks, though. It consumes a lot of electricity each winter. If your heating ducts run in a crawl space or attic space, or if your furnace is in a cold basement, you could end up wasting more heat than you move around.

Your local heating contractor probably has supplier catalogues with adjustable grilles and grille/fan combinations you can check out.

While it may seem beside the point, I think one of the best ways to improve the performance of whole house heating with a single wood stove is to invest in energy conservation projects around the house to make it more efficient.

Finally, the only way you'll find out how your particular house performs with passive grilles is to try it.

John

Wood stove clearances to combustibles

I've read much on wood stove clearances to combustible walls. But the wall where I want to install my stove is noncombustible (brick and block). Do I follow the guidelines for a "protected wall" or can clearances be further reduced since the wall itself is noncombustible?

Also, if I leave the hearth area surrounded in brick and block can I use wood furring and sheetrock 48 inches from the stove on the same wall? In other words, how much does the brick/block transfer heat to wood attached above, below and adjoining ? Thank you!

Bob

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Great questions, Bob. You don't have to protect noncombustible walls, so you could put the stove right up against the wall. Mind you, the heat loss is very high through such walls, so you're going to loose some efficiency. If you put up some shielding as if the wall were combustible, you'll get quite a bit more heat into the room.

I think if you use the dimensions from the list of shield size requirements here to determine how far combustibles must be placed from the stove, you'll be okay.

John

 

Outside Air Source question

Hello, I enjoyed your site and read over all the information I could find on Outdoor combustion air, as well as your Q&A section. I did not see this particular question answered, so I will ask it.

I use a forced-air wood burning furnace in a basement, plus an airtight woodstove in the kitchen upstairs. Because I often had trouble starting a fire in the furnace when the woodstove was working, I surmised that the basement air was at too low a pressure to provide enough draft for the furnace (since the woodstove upstairs was drawing combustion air out of the house). I installed a metal 4 inch duct bringing outside fresh air to the combustion air inlet on the furnace, and this helped a lot. Now, people are telling me that the outside air is not a good idea, because it is so cold. If it's -20C outside, I'm pouring -20C air into my combustion chamber, robbing the fire of its heat. I hadn't thought of the combustion air temperature being a factor, but I suppose using indoor air could result in a hotter fire.

If this is true, can I put a fan with a safety thermostat on an indoor air intake, so that I get improved draft when the fire is struggling? (when first being lit) The thermostat would cut out the fan once the fire is established. What do you think?

John

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Hi John,

Without inspecting it and running a pressure test on your house it's impossible to tell why you got an apparent improvement in start-up performance after you installed outdoor air. However, as we point out on the site, basic physics and research conducted to date do not support outdoor air as a solution. Sometimes wind plays a role in flow direction in a duct running to outdoors and if you're lucky, the wind might cause flow in the desired direction. Not knowing why you had start-up problems in the first place, makes it pretty hard to assess why the outdoor air supply seemed to help.

I would very much doubt that the wood stove operation is the direct cause of the furnace start-up problem, unless your house is extraordinarily tight.

Cold combustion air is just one more of the problems with outdoor air supplies.
If your chimney runs up the outside of the house, that is likely your problem.

See our Chimneys section for articles on outside chimneys.

Have you tried just opening a window in the basement to help get the furnace started? That's what most people do to correct a backdrafting chimney. It's not a cure but a band-aid. I think you should get a good chimney sweep in to look at the system and help you diagnose the problem.

John

 

Smoke spillage from system design

My husband and I just put in our first woodburning stove. To start, our stove is old, maybe an antique, there is no name on it, just #24 Air Tight. We bought it used. Our home is a Bi-level. The stove is on our lower level, with the flue pipe 6 inch oval to round going up and out to the outer wall. The outer pipe is triple insulated up the outside of our home. As I read through your sight, we don't have the most ideal set up...90 degree angles, etc... At this point we are having a few problems. Since we did not purchase the stove brand new, no one seems to want to help...professionally.

Our main problem is spillage of smoke into the house. This seems to happen on the onset of building a fire, but occasionally after 4-5 hours of burning, we will reload and a little smoke will come out the side door.

The stove is burning around 350 degrees. We have a damper in the front of the stove, and in the flue pipe. We have been playing around trying to find the right angle or opening to keep the most heat in the house.

Are we doing something wrong? My main concern is the spillage of smoke and smell of smoke in the house.

Also, should we have a carbon monoxide detector down by the stove? We have been getting many opinions on what to do: Put an extension of 2 feet of insulated pipe on the outside, take off the cap, use a blow dryer to create a "warm draft", get a new stove.... Any other suggestions? I appreciate your help. We are so excited about using the stove, we just want it to be safe and efficient.

Thank you, Celeste

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Hi Celeste,

I strongly suggest you get some professional help. Your system design is such that smoking will probably be chronic, despite whatever you do. It is not because of the elbows, but because:

• the chimney runs up the outside wall
• the stove is located on the lowest level of the house
• the chimney is air cooled

Read the chimney section of the site for details.

Yes, you should definitely install a CO detector because you could have a hot backdraft late in the burn while you sleep and the exhaust from a coal bed has little smell but high CO levels.

Perfect wood heating systems have these characteristics and yours has almost none of them.

John

 

Why should I believe you guys about outside chimneys?

Very nice site. Thank you.   I am considering putting a wood stove in my basement and running the chimney out the wall and up the house. I have done a lot of research on this 'cause that's the kind of guy I am. I know that a chimney is most efficient when it is run through the warm part of the house. Yet, many people do run the chimney on the outside of the house with out any problem.
Manufacturers installation books even provide diagrams and instructions on how to do this. But you make it sound as if it should NEVER be done. Is it really THAT bad?

Also, you seem to be very against putting a stove in the basement especially with fans blowing the air upstairs. I understand the THEORIES you espouse to... but in practicality I know a lot of folks that heat their basements AND their upstairs pretty nicely with a basement stove.

As I said, I have done a lot of research. There are many other websites, books, etc on the subject besides yours. Yet your site seems to be the only information source that is SO opposed to these two practices.

Thoughts? Dave

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Hi Dave

Good questions, and probably ones that have occurred to many of our visitors. I'll start by saying that our strong stance on outside chimneys and basement installations has nothing to do with opinion or belief.  Blame it on the laws of physics.

You might find this difficult to believe, but a good understanding of how chimneys function in relation to the houses they are installed in (or outside of) is a very recent development, certainly within the last thirty years.  The other experts you may have encountered who are not as decisive as we are on the subject have just not yet caught up with the science of the matter. We were fortunate to have been present as the new knowledge of chimney function began to emerge. Plus we have a combined 70 years of experience behind us during which we've been able to confirm scientific theory through field observation. That is, we've seen a lot of spilling and backdrafting systems.

We have also seen systems that work perfectly, regardless of outdoor temperature or wind direction or speed.  Once you've come to understand the underlying physics and you've seen hundreds of systems, the patterns start to become obvious.

Just to be clear, it is the outside chimney that is the biggest problem, especially if combined with an installation at the lowest point of the house.  If you install your stove in the basement, but run the chimney straight up through the house, it will work fine, provided other good design rules are adhered to.
You wonder why so many people apparently do fine with outside chimneys and basement installations?  Here are some possible explanations from our experience:

• They're not doing fine, they're bluffing, because most people like their wood heat system even if it doesn't work perfectly.
• From our experience, people are incredibly tolerant of badly performing wood burning systems.
• The problems of outside chimneys are much worse at cold outside temperatures, so folks in Georgia don't experience them as severely as people in Alberta.

The physics of air pressures and flows in chimneys and houses is incredibly complex and is influenced by a huge number of variables.  Sometimes those variables combine to allow a system that should not work well to perform acceptably, especially in the eyes of the owner.

We are fully aware that when you look around you will see a huge number of outside chimneys, maybe the majority, which suggests that architects and builders know something about chimney function and that we must be over-stating the problems. They don't and we aren't, but I guess you'll have to reach your own conclusions.

Regarding the attempt to heat the upstairs of a house from a stove located in a basement, check through our question and answer section and you'll find lots of people asking how to get the heat upstairs, and that is just a small sample of that type of question we've received.  Those of us who locate our stoves properly, in the space we want to be the warmest, are much more comfortable and we burn a lot less wood. Plus, we get to enjoy that incredible fire all winter long. A basement is no place for something that beautiful.

John

 

Integration of a wood stove in to a heating system

I am new to heating with wood. Recently, we purchased a new and relatively efficient wood stove to heat our one year old, 1,350 square-foot home. Until now, we have been heating with a forced hot air LP system which has proved to be expensive. The stove is located in our basement and does a great job, but we would like to integrate it with our existing ductwork, distributing the warm air more efficiently upstairs. I would sincerely appreciate any suggestions that you may offer.

Thanks, Ben

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Hi Ben,

If you want to heat the entire house with a wood burning device located in the basement, you need a furnace. It is potentially hazardous to try to use a space heater as a furnace. Plus all building and installation codes prohibit any sort of interconnection or close linkage between space heaters and forced air duct work.
We strongly recommend locating the space heater in the area you want to be the warmest, which is usually the main floor.

John

 

How do I  get heat upstairs?

I am building a new house with a walk out basement. I'd like to install  either a fireplace or a woodstove (preferred) with some method to  passively capture the heat and distribute upstairs... i.e. I do not want  to have to daily tend the stove, only fire it up when the temperature really drops.  Any suggestions?

Jim

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Jim,
We get a lot of mail from people who have installed stoves in basements expecting the heat to rise naturally. Here is an example:

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I have a ranch home with a woodburner in the basement. I am having trouble getting the heat from my basemet to the upstairs. The door to the basement is wide open. The uptsairs is stays around 65 and the basement is about 90.  Can you offer me any suggestions on how I can even out this heat. I put in one register but not much changed. Hot air didn't go up, cold air came down.  My ceilings in the basement are finished with drywall.  Anything you could offer would be appreciated.

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This was my response:

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Wood stoves are space heaters and as such should be located in the space you want to be the warmest. We strongly discourage the idea of putting a wood stove in a basement, when the space to be heated is upstairs. The problems you experience are identical to those experienced by everyone who tries this.

Whatever you do, don't try pumping air from the basement to upstairs. This can depressurize the basement and cause backdrafting of the stove. If anything you should pump air from upstairs to the basement and force air upstairs that way. Ideally, you should move the stove to where you want the heat because you will never satisfactorily resolve the too hot basement, too cold upstairs problem.

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This is what I suggest. Buy a really nice looking stove and put it it the room where you spend most of your time, like the living or family room. It will be there when it gets very cold outside to provide cozy warmth and will also provide a spectacularly beautiful fire any time the mood strikes you. You'll get the best of both worlds.

John

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Jim replies:

John, thanks so much for the reply.  I think we will put the stove in the basement to keep the BASEMENT warm. Thanks.

 

Heating upstairs with a basement stove

I was reading on your site about having a woodburner in the basement and trying to heat the upstairs. You said not to pump the air upstairs but to pump it down to the basement. I have the same problem as the other reader did, no heat upstairs and really hot downstairs.

How do I pump air into the basement from upstairs? Any ideas would be a great help because I have electric baseboard heaters and it costs me an arm and a leg to pay the electric bill!   Please help!!!!

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Hi,  

How exactly to force air downstairs depends somewhat on your house layout. In simple terms you would need to install a fan that forces air from upstairs to the basement to slightly pressurize it. Then you provide a path for air to flow upstairs. Where you put the fan and grilles depends on your house. You might talk to a heating contractor or heating equipment wholesaler to get some options on fans and layout. It is not very complex.

John

 

Chimney through the wall

Hi! Just found your site...Thanks for the great info!  We are installing a woodburning stove according to town regulations. We have cut the hole through the wall through which to put the metal chimney. We don't have a manual to the stove we were given. We see how the chimney connects on the outside of the house, but we don't know the best way to seal it off, meaning where the circular metal lip meets the outside of the house at the hole, to prevent rain from seeping in and what not.  Is there a typical best way to do this? Thanks.  Looking forward to your help.

Roger

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Hi Roger,

I guess I should first mention that we strongly discourage the venting of wood stoves through chimneys routed up outside walls.  By far the more preferable approach is to run the chimney straight up through the warm part of the building.  Chimneys that run up outside walls make the system vulnerable to cold backdrafting and this is by far the most common type of venting failure with chimney vented systems. See our Chimneys section for detailed information.

The best way to seal the trim collar on the outside of a building depends a lot on what the wall covering is.  If it is lapped siding, whether wood or metal or vinyl, some installers will remove the section of siding that will be covered by the trim collar and replace it with a piece of plywood to give a flat surface to seal against.  This usually provides a slight overhang of the siding to shed water over rather than under the collar. Regular weatherproof caulking is then used around the edges of the trim collar to seal it against the weather. You can use silicone sealant between the chimney surface and the metal trim collar. If you can't get the trim collar to lay flat against the wall, you may need to add a flat surface to the wall, then flash the top and sides with thin sheet metal to seal it. 

The kind of questions you are asking cause me concerns about whether you can do this installation on your own and get it right. It is rare that a first timer can do that.

John

 

My plaster ceiling is turning yellow from the stove

This is my first year that I utilized a wood burning stove.  I consider  myself a rookie.  The wood that I used was split and I could peel the bark off. Unfortunatly the brand new plaster ceiling started to turn color.  What  did I do wrong?  Did I used improper wood ? Marcel

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Marcel,

If you can smell wood smoke at all in your house, then you have a serious problem and need professional support to get it corrected right away. You should never smell wood smoke inside the house if everything is working right.

If you can't smell wood smoke, then the discoloration probably has to do with the convection current created by heat rising off the stove.  I have a white painted ceiling above my wood stove that has been there for many years and it is not discolored at all. I don't know what conditions would lead to rapid discoloration, but if you never smell smoke, then it can't be turning yellow because of smoke from the stove.

John

 

Is wood heat for me?

I am considering changing my house from electric to wood heat.  Wood  heat would probably by the most cost effective option since my wood  would be free.

I need to heat a well insulated 1000 square foot house with a 1000 square feet of un-insulated basement. The climate is northern lower Michigan, normally winter temps are about 20F but can be sub 0F at times. What type of wood heat system do you suggest?  A lot  of people have suggested out door boilers. Would a simple wood stove in  the basement be enough to heat the house without installing duct work? Thank you for your time

Matt

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Matt,

You could heat your house very nicely with a medium sized wood stove, but we wouldn't recommend putting it in your uninsulated basement. Space heaters work so much better when they are located in the living area that you want to be the warmest place in the house. That way someone is around to monitor it and tend it as necessary and you have the added benefit of watching the fire all winter. People who put space heaters in non-living area basements and hope to heat the living area upstairs with them usually find their basement is way too hot, their living area is never warm enough and they use a lot more wood than they should.  I heat from the main floor and don't put any heat in the basement and it gets chilly down there, but never close to freezing.

And your house is WAY too small to even consider heating with an outdoor boiler. I think you would find it would smoke most of the time and deliver about half the efficiency of a good stove.

John

 

Wood burning to heat several rooms

I am looking for a fireplace design that will send hot air to several rooms as well as have a nice living room view of the fire burning in a typical fireplace. I have seen something like this on THIS OLD HOUSE or one of Bob Villa's programs. Can you lead me to such a product? Thanks!

Hopeful

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Hopeful,

There are several fireplaces like this: Security BIS II, RSF series of fireplaces, Regency WarmHearth, Fireplace Xtrordinare, and there are others. Check with the specialty fireplace shops in your area. They will carry one or more of these.

John