Outdoor woodfired boilers?

[mrcaptainbob]

Our house is a 4,000 sq. ft. two story brick built in the early 1860's in south central Michigan.
I put in a Central Boiler unit about six years ago. It was October when I shut off the boiler in the basement and it hasn't been turned on since. Filling a 500G propane tank every 4 or 5 weeks was dipping too far into the retirement funds. Ten acres of woods is NOT enough to feed this animal, as I soon found out. I am fortunate in having neighbors that want their wind rows kept clear. Besides all the (true) stuff mentioned about laws, smoke direction, wood access, and the effort to cut and stack, I hate being a slave to this. Although it takes about 1.5 hours of cutting/splitting/stacking = (1) week of heat, it makes no difference if it's raining, if you have a head ache, feel lousy, sore back....the stove is hungry, it must be fed. I go through 16 cubic feet a day for about six months. About a full cord a week. Summer time is considerably less, of coarse. This warms two water heaters, both bathroom floors (hydronic floor heat) and the four zones for the house where it's T-shirts and socks warm. My wife's a Texan and still needs higher than normal temps for comfort. If I had to do it again I'd go geothermal. Still in good shape at 66, but not sure what the future holds. Would like to swap this OWB for a geo unit before I can't do the wood thing anymore.

 

[dave1949]

Our house is a 4,000 sq. ft. two story brick built in the early 1860's in south central Michigan.
I put in a Central Boiler unit about six years ago. It was October when I shut off the boiler in the basement and it hasn't been turned on since. Filling a 500G propane tank every 4 or 5 weeks was dipping too far into the retirement funds. Ten acres of woods is NOT enough to feed this animal, as I soon found out. I am fortunate in having neighbors that want their wind rows kept clear. Besides all the (true) stuff mentioned about laws, smoke direction, wood access, and the effort to cut and stack, I hate being a slave to this. Although it takes about 1.5 hours of cutting/splitting/stacking = (1) week of heat, it makes no difference if it's raining, if you have a head ache, feel lousy, sore back....the stove is hungry, it must be fed. I go through 16 cubic feet a day for about six months. About a full cord a week. Summer time is considerably less, of coarse. This warms two water heaters, both bathroom floors (hydronic floor heat) and the four zones for the house where it's T-shirts and socks warm. My wife's a Texan and still needs higher than normal temps for comfort. If I had to do it again I'd go geothermal. Still in good shape at 66, but not sure what the future holds. Would like to swap this OWB for a geo unit before I can't do the wood thing anymore.

Yikes. Do you have one of those beautiful old brick farmhouses? There was a period of time around 1900 where apparently prosperous farmers built those. A few came with the mini oil booms that passed through back then too. (I am from Bowling Green, OH originally.) I like the looks of those old homes. I suppose they aren't so easy to heat. I have read histories of that time period here in Maine. It was nothing to have 25-30 cord of wood layed up back then.

I really think your best solution is to move to Texas But if you want to stay in Mich. - Is your house insulated as well as it could be? The best thing would be to start by reducing the energy requirements if that is possible. If you haven't examined the idea in a while, there lots of new materials and techniques that work pretty well. Getting a quote from an insulation contractor should be free and may give you some ideas.

Dave.

 

[mrcaptainbob]

We really like the layout of this old house. Plus it has a great history. We are but the sixth owners. It was refurbished in the recent past, maybe thorty or so years ago. Not recent enough to have caused them to be more insulation friendly. Lots of smart stuff done, plenty of not-so-smart stuff. I'll get off this now and return to the original subject. Don't mean to hijack the post.

 

[mikefromnh]

Mr captain

I'm sure the work gets old - but look at the bright side, at 2.50 a gallon for propane you are making over $200/hr when you cut wood!

 

[LD1]

As already mentioned, Definatally take a good look At Arboristsite.com

I know several people who have them and have seen many in my area. The main advantages of them are
1. The mess is outside
2. The fire hazard is outside
3. They can heat mutiple building easily
4. You dont have to add wood every few hours

But they have serious drawbacks. There are 2 reasons in which they smoke a lot. First, Inexperienced wood burners treat them as incenerators. They burn garbage, trash, green wood, etc in them. The types of things an experienced wood burner would never burn in their house due to low heat output, risk of chimney fire, and smell.

The second reason is these things have a huge fire box. It is nice cause it doesn't require fixing that often, but when the water is at temp and doesn't need heat, it chokes the fire out and lets it smolder, then when it needs heat, it forces air in and starts burning again. The chimney height is also another concern. Most houses have chimneys that are 20-30' in the air, which helps not to smog out the neighbors. The OWB's have very low chimneys.

Given the cost to have one of these installed, and all the added labor involved of cutting wood/buying wood, and having to fix the fire when its -10 outside, I'd consider getting a geothermal unit if you have the required land to burry the ground loop. A few people I know that have recently went with geo, got quotes on bot the geo and OWB units. The OWB's were between 8000-12000 and the geo's were between 12000-16000. IMO that is not much more money and you don't have to worry about firewood. The only way I'd even consider a OWB is if I wanted to heat multiple buildings.

And if you have a shop to heat, another option is an indoor wood boiler. I know a few people that have them. (homemade) It is basically a OWB without the insulation and outer sheetmetal, setting in the shop. Radiant heat heats the building and boiler water heats the house.

 

[Low Bucket]

As already mentioned, Definatally take a good look At Arboristsite.com

I know several people who have them and have seen many in my area. The main advantages of them are
1. The mess is outside
2. The fire hazard is outside
3. They can heat mutiple building easily
4. You dont have to add wood every few hours

But they have serious drawbacks. There are 2 reasons in which they smoke a lot. First, Inexperienced wood burners treat them as incenerators. They burn garbage, trash, green wood, etc in them.

Very well said!

 

[Jeepnford]

Like stated earlier I'm building one from some plans I aquired. I could of built the firebox about 1/3 smaller. It's about 36 cu ft. Since it didn't figure in an ash pan I might build a false bottom and add a grate to decrease size a bit,possibly increase the water jacket size and only burn very dry wood. I wouldn't do it except I want to heat my 1200 sq ft shop along with the house.

 

[Hookblock]

I have a central boiler it came with the house, there is a propane fired boiler in the basement, with baseboard heat. What I did is run the wood boiler lines to a water to water plate heat exchanger on the house boiler. Then unhooked the control wires to the boiler, so when the thermostat call for heat only the pump on the boiler runs. The problem I have with the setup is the heat loss from the boiler to the house, and hope to have that fixed this summer.

 

[AHNC]

I'd be inclined to shop around for a wood boiler that I could put in the basement. I'm a manuf rep in the heating and AC industry for the New England territory. This is a great time of year to check with the local distributors to see if they have a remaining wood boiler available. I suspect you could get a heck of a deal this time of the year.

The old rule of thumb is that if you burn wood the 30 coldest days of the year you will reduce your fuel by 50%. I prefer to have this system in the basement where I can better maintain/feed it. I don't want to have to brave the elements to be comfortable.

I built a wood boiler for my Dad a long time ago and piped it into the baseboard system. We also put a big sheet metal enclosure around it with a duct up to a big floor grill, so we recovered a lot of convective heat into the house.

First, and without fail, get your chimney checked out and lined if necessary. If you don't have one run a factory built chimney up thru the house. Not up the outside wall. Don't forget to talk with your homeowners insurance folks.

 

[SpringHollow]

But they have serious drawbacks. There are 2 reasons in which they smoke a lot. First, Inexperienced wood burners treat them as incenerators. ....

The second reason is these things have a huge fire box. It is nice cause it doesn't require fixing that often, but when the water is at temp and doesn't need heat, it chokes the fire out and lets it smolder, then when it needs heat, it forces air in and starts burning again. The chimney height is also another concern. Most houses have chimneys that are 20-30' in the air, which helps not to smog out the neighbors. The OWB's have very low chimneys.

My boiler is greatly oversized. Someone wanted my smaller boiler of this brand and i wanted greater than 16 hour burn times for the times i needed a longer burn. This boiler has twice the capacity. With the previous brand I had, oversizing was a disaster. With this brand, i was pleasantly surprised to see that oversizing is not an issue just like the factory promised. My boiler shuts the fire down completely when the fan is not on. Sometimes you see the slightest whisp of smoke out of the chimney. If you open the door, there is literally no glow. But there is enough heat still in the coals that when the fan kicks on, it starts the fire right up. I do not see the big belch of smoke that i see in many boilers. It really smokes very little even when i was burning wood in Dec. from a log load from last January that i did not cut and split until late July/early August (happened to be in the front of the pile and in the way so it got burned).

Ken