Building a Wood Boiler

[TessiersFarm]

First of all I am so pleased to find this site, Lots of very valuable Info, Thanks.

I am in the process of building a wood fired boiler from scratch. I have measured, studied and obsessed over several factory built and a couple of home made units. My boiler will be installed inside my garage and piped underground to the boiler room of my house. I am starting with 2 tanks which I plan to nest into one another to form a full water jacket with a capacity of around 200 gallons of water. I am going to install a pressure relief valve with a pipe directly into the fire box so that if the unit overheats it will dump the water onto the fire. I also plan to install a secondary (freeze plug, if you will) device that will blow out under pressure. I believe my boiler operates at around 6 or 8 psi now so the wood boiler will do the same. My plan is to run a circulator constantly with a NO zone valve and a unit heater in the garage and a loop feeding the boiler manifold in the house with a relay so that when the wood boiler is up to temp the LP boiler will not start. I have a small blower that will be installed in the front of the unit to force draft when nessesary, and plans to build a by pass damper for loading.

I am looking for any suggestions and or experiences to maybe prevent me from making un-nessesary mistakes, and or Ideas to maybe improve my system.

Thanks in advance and again its a pleasure to be part of this group.

 

[WoodNotOil]

https://www.hearth.com/talk/threads/29830/

https://www.hearth.com/talk/threads/24064/

https://www.hearth.com/talk/threads/11262/

Take a look at the above and do some searches in the boiler room. Several people have done similar projects. One thing we often encourage here is to incorporate the newest technologies (such as gasification) instead of just copying outdated inefficient methods of burning wood. I am sure others will have suggestions when they get back on after the holiday.

 

[jebatty]

What you are proposing, as described, while ambitious is IMHO not only old news but news that might soon be history. Water jacket boilers are extremely inefficient, some describe them as smoke dragons, and not only extremely wasteful but expensively wasteful of wood if you have to buy it.

If you want to build something, why not go for top shelf and research and build a gasification boiler? You will end up with something that will be the attraction and envy of your friends and neighbors. And your mechanical and engineering expertise will rise to a new level.

 

[herbert]

I keep hearing the wood boiler units being "trashed" and the gassifiers being the way to go. Not being familiar with the gassifiers i am sure there must be some validity to it.
On the flip side of the argument, i purchased a pacific western OWB four years ago (315 gallons of water and a BIG firebox) and will admit it is a 'Wood Hog" , at the same time crediting it for heating my 7000 sq foot poorly insulated production shop.
This year i purchased a new Taylor 750 for the home (2 furnaces-hot water heater--hot tub and inside swimming pool) . This OWB has 600 gallons of water and a fire box that is less than 3' square and i can get a 24 hour burn with it in "COLD" windy weather with well seasoned hardwood unsplit logs that average 24" length and 10" diameter.
I did try some split wood that was a bit green and it would need a small amount of wood added to get the 24 hour burn. I think these stoves have improved a lot over the past few years.

 

[SnaykeByte]

I very much agree.

 

[Nofossil]

I keep hearing the wood boiler units being "trashed" and the gassifiers being the way to go. Not being familiar with the gassifiers i am sure there must be some validity to it.
On the flip side of the argument, i purchased a pacific western OWB four years ago (315 gallons of water and a BIG firebox) and will admit it is a 'Wood Hog" , at the same time crediting it for heating my 7000 sq foot poorly insulated production shop.
This year i purchased a new Taylor 750 for the home (2 furnaces-hot water heater--hot tub and inside swimming pool) . This OWB has 600 gallons of water and a fire box that is less than 3' square and i can get a 24 hour burn with it in "COLD" windy weather with well seasoned hardwood unsplit logs that average 24" length and 10" diameter.
I did try some split wood that was a bit green and it would need a small amount of wood added to get the 24 hour burn. I think these stoves have improved a lot over the past few years.

There's no doubt that some manufacturers are making better units, and hopefully more owners are learning how to operate them better. Improved efficiency and cleaner burning is all good.

Still, a true gasifier will burn far less wood and far more cleanly than the best conventional boiler operated perfectly with ideal wood. I get four minutes of light smoke once a day when I light my boiler. The rest of the time, there's no way you could tell I'm burning wood (other than the big pile under the deck ;-) )

 

[TessiersFarm]

I am building this boiler purely from an economics point of view. I burn wood now in a wood stove and pay little or nothing for most of the wood I burn. I use around $700 to $800 dollars of fuel per year. If I completely eliminate the fuel bill that is still a long payback on almost any factory system. I am not looking to invent something new or impress anyone, I am simply looking to cut my fuel bill a little without spending a whole lot of money out of pocket.

On a side note I got a line on an old feller that has an old wood boiler in his basement in good condition, along with a 1000 gal storage tank. He said someone can have them if they get them out. Will be calling him this week.

 

[dairyfarmer]

When I went looking for a wood stove I looked for two things the first was Labor efficiency. The second was how efficient was the stove on wood use. Cutting the wood 18" long and splitting it up into splinters throwing it into a basement and ranking it up just so I use a little less wood does not sound efficient to me. I would much rather be able to bring the wood to my house 100 inches long cut it three times scoop it up with the skidloader and dump it in the wood shed green or dry. If I burn a few chord a year extra I will for that convienience. Now I'm not against gasifiers or indoor wood stoves I am just making a point that different people measure efficiency in different ways. I also agree with Herbert that outdoor wood boilers have come a long way and they are still making improvements.

 

[herbert]

I hear what you are saying about cutting logs into 4 foot pieces and skidding them in--thats what i do with my western pacific at my production shop. The Taylor i got this year for the house will only take 30" logs--i cut them 24 so i can rake the coals forward after a 24 hour burn and put the 24" pieces all the way to the rear so the fire is spreading back as it burns.
Am still amazed at the efficentcy of this Taylor compared to the Pacifc Western. The Western I fill twice a day with 3 times more wood.