OT: outdoor wood furnaces?-Hvac guys opinion.

I have seen on the internet a few companies that make those outdoor wood boilers. My question is.....Is there anyone on this site that knows of a outdoor wood furnace that is forced air only instead of a boiler. The reason I ask is cause I called a place in Minnesota yesterday and the base price on an outdoor boiler is $6k, hookup is not included. Total price would likely be $10k.

I really think that I could make a small cinder block shed 5 feet away from my house with a large wood stove in it and then use a large insulated duct blowing air into my crawl space, this would be used while I was at work, (much less fire risk). I would run my pellet stove when I got home from work.

My home is a 2300ft. sq. ranch with a 5 block crawl, I am in Michigan--cold in Winter.

If I were to do this I would make the shed out of cinder block with R-10 foam board inside for insulation, metal roof, a small grill vent up top and the duct would be 2 feet off the bottom and run horizontallly to the crawl vent. Inside the crawl space at the duct would be a thermostatically controlled fan.

Is this idea not practical? Is it to inefficient? I have a lot of dead elm and some ash trees for fuel.

One of my former neighbors thought he could do what you suggested. Notice I used the word FORMER! Fire chief said he'd never seen a house go up so fast. Spend the bucks, do it right. Get a decent water boiler wood furnace, and feed heat into your ductworks thru a hot water heat exchanger.

Ahhhh......what did this guy do? An all wood shed cooked to a crisp and then poof!
Fill me in on details, wood stoves are safe if cleaned and run properly, like no coal, or flammables used for starting.

check out www.yukon eagle.com I have sold andinstalled these send me a email I will
tell you about them.

One thing I'm thinkin' is, unless you had some kind of cold air return from your crawl space, you'd be heating extra cold outdoor air, which could easily be 60 degrees colder than your crawl space air. Using foam board insulation inside your "furnace room" also sounds iffy. There once was a stove company named Juca (don't know if it still exists) that made wood stoves to hook up to ducts. Using one of those would be a head start.

Several years ago,I helped a guy build a very large outdoor wood stove.He installed it inside a cinderblock building.He then ran a 24" u shaped pipe around the inside of the building then underground to the house, hooked a fan to one end of the pipe and circulated air through the loop. He the filled the building ,covering the stove and the pipe with white sand, only the front door of the stove was exposed.He claimed that after the sand got hot he could have heat for two days after the fire went out.

Forced Air Only units are a waste of money - I agree with Ray -- do it right -- If you don't have a background in heating -- get some local advise in your area to look at every possibility ////

the cost of heating this winter is going to be a real shock -- and more of a shock every winter after that -- so at least your thinking about doing it different as long as you have the wood.

You can try charmaster they ship these all over the US. Scotty
Untitled URL Link

Sure a lot of headaches to solve a low fire risk. Maybe a europian syle masonry fireplace is the ticket. Fire it up once a day. It burns for 30 to 60 minutes. The mass warms all day without a fire or an open flue. Been around for hundreds of years. Pre electicity.

I live in MN and I bought my outdoor boiler from a machine shop that is about 15 miles from me. They build and sell at least 100 a year. Almost every person I know who has an outdoor boiler has one built by Dale. I paid $2400 for mine in 2005, and it heats my house perfectly. My parents bought one from him in 2000, and the paid $2100 for theirs. They heat a 28x88 ranch style house and I heat a 24x30 three level farm house. Both of us are very satisfied. If you'd like the company name and phone number, send me an email and I'd be glad to help you out.

Sorry, forgot to open my email. Here you go.

That is exactly what I have at my home. I installed the furnace outside - about 30 feet from the house and built a room around it - attached to the house. Has a virtually fireproof chimney built to Canadian specs instead of U.S. Canadian specs require a much more burn-out proof and better insulated chimney.

By having the room and furnace attached to our house - we never have to go outside to load it, we can store two full cords of wood in the room where it gets very dry, and we even hang our wet clothes in there in the winter and they dry very fast.

This setup that I built has exceeded my expectations. It is hot air for heat - with hot water coils hooked via thermo-siphon to an 80 gallon storage tank. That storage tank is hooked in series with a 30 gallon propane heater. The wood makes more hot water than we can use all winter. Summer we have solar hooked to the 80 gallon pre-tank. So, the propane heater rarely comes on.

Hot air heat ducts are 8" and 10" insulated flex-pipe - stuck into hard plastic corrugated conduit (culvert pipe) where they are buried underground to several areas of the house.

This room and furnace are installed at ground level - NOT in the basement. The original part of the house was built in 1830 and I added a two-story addition that's larger than the original house. So, the house sprawls a lot sideways and is not easy to distribute heat in. As you can see in the photos - there's much I did not completely finish. No siding on the furnace building, for one thing. I build all myself - no help from anyone - and also have a little kid with me all the time - so things go slow at times and I often switch projects, back and forth.

The only downside to this furnace hookup is the electricity the blower uses. With a wood furnace - in the winter - the blower runs just about 24 hours a day when the fire is hot. It has to - unlike an oil or gas furnace that comes on and off. We are on a solar 5400 watt grid-tie electric system so we don't pay anything for electricity - at least not by the month. Having solar is kind of like paying all your future electricity bills all at once. But, with prices going up - we're making out. I have a total out-of -pocket investment in the solar of around $20,000. More half of the total cost got payed for by State and Federal incentives.

Our electric consumption goes from 275-300 KWH per month in the summer - to 600 KWH per month in the winter - and much of that increase is due to the furnace blower running all the time. In our case, we still make more electricity overall - then we use so it's no problem.

Keep in mind the chimney. It's kind of a "corporate kept secret" in the U.S.A. that most companies that make stainless steel pipe - make a U.S and a Canadian version. Very little price difference - but the Canadian pipe is far superior. Takes a lot of jerking around to get it though - when you are a U.S. citizen. Luckily, I live near the NY/Canuck border.

I also suggest that if you plan to have your hot-air furnace heat your domestic hot water - do NOT use a circulator. It's a total waste. Since a wood fire runs constantly, slow and steady - it will make more hot water than you can ever use with just a thermo-sipon hookup.

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_2298.jpg" target="_blank"> </a>

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_2292.jpg" target="_blank"></a>

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_2291.jpg" target="_blank"></a>

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_1975b.jpg" target="_blank"></a>

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_1982-1.jpg" target="_blank"></a>

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_1980-2.jpg" target="_blank"></a>

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=thermsiphon_tempering_tank-1.jpg" target="_blank"></a>

<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_1977-1.jpg" target="_blank"></a>
<a href="http://s104.photobucket.com/albums/m162/jdemaris/?action=view&current=100_1975-1.jpg" target="_blank"></a>

I previously had an outdoor wood-fired boiler and now use a hot-air, wood furnace with a room built around it. I described it above in another post. Don't tell me it's a waste - this thing works better than anyting else I've had - or seen in my area of New York - and there are a lot of outdoor boilers around here. My systems uses a lot less wood than the outdoor boilers.

I've been heating my home with wood for 40 years and tried many different things.

In regard to paying someone for "advice" on an non-mainsteam, alternative-type heating system? Good luck. Most people in the business are ignorant on the subject. Do your own research.

One note. A wood fire needs to be hot to be efficient. So, the most efficient wood-heating system is one that runs either full-bore, or not at all. But, that is usually not feasable with a home-heating system - so some things are a trade-off. If you had a lot of room to build, and money to spend, you could built a hot-water system with a huge storage potential. Then, run the furnace once, every few days - full bore - get the water hot - and then shut down. But - there's is a down side to it, also.

So - one idiot does something wrong - and the entire concept is therefore no good?

That is simply rediculous.

Thanks for the info and the pictures, very interesting.

I'll add that our weather here is probably colder than you get in Micigan - unless you live at a northern tip of the U.P. We get 35 below F here at times - much of Michigan weather seems to be not as cold, less extemes, but a longer cold over a long time. I spend a fair amount of time at the northern tip of the lower peninsula - just below the Mac bridge in Presque Isle County. I have a house and small farm there. My land up there seems to have a week later Spring - and a week earlier winter - but with less extremes in weather than here in NY. Also - a lot less good hardwoods up there - but you have to take what you can get.

Also - to add one more comment. The wood-furance I am using is very heavy plate steel and of simple design. It's made by a farm equipment company - Meyer Manufacturing in Wisconsin. I used their Woodchuck 4000. A fire that could spread to the house - the way this is set up - is close to impossible.
There are other wood furnaces out there with hot-air. Some, e.g. the "Caddy" made in Canada is the most efficient hot-air furnace ever tested by the EPA. But . . . the Canucks in Québec refused to sell one to me here in the U.S. so I never got to try it. Then there's the Yukon that someone else mentoned here. It can be equipped as a combo with an oil-gun to start the wood fire. I had one, I personally didn't like it. Built thin and cheap in my opinion. Kalamazoo used to sell one that is similar.

I agree. We have an indoor forced air wood furnace that has been in use for 20 years now. never any problems, always has heated the home well. Any wood furnace, stove, boiler that is operated wrong, or burning green wood can have a home go up in no time. Common sense with wood, keep an eye on the chimney, flue and burn good hot fires. We burned 6 cords this year to heat a 2400 sf victorian at an average temp of 76 all winter long. From the fall till this spring we have used maybe 100 gallons of propane. Which is the furnace, stove, and dryer. Its not a top of the line model, and alot of people don't like them, but its gotten its money worth over and over again. Some people can afford a 10,000 dollar system. A wood furnace will heat just fine from a local supply store thats thousands less.

I live 100 miles north of the Mi-Ohio border. We dont get -35f temps here, havent had that in over 10 years. The winter is 10-30f for most of the time, it does get down to 0f and -10f for a few weeks but that is all. I like your pictures, looks like a lot of heat output.

I talked to a guy today and he said that he is heating with a heat-a-lator wood stove insert and he is pretty much ready to tell the propane suppliers to screw-off.
I have a lot of research to do on the internet and some insulation upgrades.
I really want to make the propane use minor, like 400 gallons/year and half of that being used to take showers and run the dishwasher.

I have one question. Most homeowners ins. policys state that wood burners must be a minimum of 50' from any insured building. Can you get heated air to travel that 50' and another 50' or so under the home and STILL be warm enough to heat the home?

You say "most" homeowner's policies state that?

I've got three houses and every one of them has wood heating - most in duplicate (wood furnace and a smaller wood stove). In all three, the wood stove in inside the house. In two the woodfurnace is down the basement, and in the third - in a room attached to the house. In addition, the house we live in full-time has - the wood furnace attached to the house, a woodstove in the living room, a Rumford wood-cooking fireplace and bakeoven in the kitchen, and a wood-cook stove in the kitchen. And, I had no trouble getting homeowner's insurance on any of them. Insurance guy came out, checked everything, photographed, etc.

So, when you say "most" don't allow - you've got me wondering who those "most" are?

All that counts is you get insurance that you need for a decent price. If, in your locality, for your house three companies say "no", and three more say "yes" - seems there's no problem.

I got refused by one company because I have two horses and a herd of goats. I got refused by another because I've got over 50 antique farm tractors stored in a distant field that you cannot see from the house and road. That's just the way it goes - they all have different rules.

Properly installed and operated fine however..............
There are some water furnace designs that are less efficient. Then there are those operators who stoke them as full as possible, often with un-cured firewood. Then damper the airflow way back for a smouldering fire. The operators then have to deal with high wood usage, creosoot buildup/drips and neighbours complaining about the smoke/smell.
I couldn"t imagine not having a building for the furnace to protect it from weather. And provide space to store kindling & a week or two"s fire wood.

I would like to have the contact info. Please send to [email protected] Thank you.

(quoted from post at 04:41:41 06/07/08) One thing I'm thinkin' is, unless you had some kind of cold air return from your crawl space, you'd be heating extra cold outdoor air, which could easily be 60 degrees colder than your crawl space air. Using foam board insulation inside your "furnace room" also sounds iffy. There once was a stove company named Juca (don't know if it still exists) that made wood stoves to hook up to ducts. Using one of those would be a head start.

Click to expand...

Wood burning stoves are safer than ever thanks to alterations in their designs. Most of them are even claimed to be smoke-free because of their effective ventilation systems. But you will want to make sure young children are blocked from being able to touch the stove’s surface while in use.