Outdoor Boiler

MichaelK

I'm looking into pricing out and installing a outdoor wood boiler for my home. Was interested if anyone has any product literature, one of their own, or experience installing and using these.

With heat pumps being our only source and those beginning to age I'm inclined to new options. A quick google search leads to sales and promotions. I want the nit and grit. The opinions and horror stories all please. As a plumber/fitter newly out of the field i don't need a sales guy and and installer I need manuals and others first hand experience.

Thanks all,
Michael

vtfarmer

I'll bite. When I lived in Vermont I had a drafty old 2600 sq ft farmhouse with oil hot water heat and a drafty little 700 sq ft apartment with electric baseboards. After burning thousands of gallons of fuel oil and many kWh of electricity I bit the bullet and spent CENSORED (pricing discussion is not allowed on this forum) on a new Central Boiler 550 Edge Classic after calculating that my design day BTU load for both dwellings was about 112k BTU/hr when domestic hot water is included. I did tighten both structures up with some new windows, better insulation, and chased many drafty air leaks but it was not practical to get the buildings very tight. I later ended up also adding a green house with a fan coil unit which was essentially heating the outdoors during seedling starting season.

I buried two runs of this stuff to connect the boiler to the house and the house to the barn apartment:
https://centralboiler.com/products/thermopex-piping/

It was also expensive and hard to work with, but high quality and does the job. I ended up with a ridiculous primary secondary pumping setup with about 9 circulators and a plate exchanger in the house that I built myself. If I had to pay anyone to set this up it would have been stupid expensive, instead of just crazy expensive. (all copper, lots of big fittings and valves, looked like a pipe organ)

Here's the manual for that boiler (not sure why Google gave me a UK web site for the first hit for the manual):
https://www.central-boiler.co.uk/wp-content/uploads/2018/02/Central-Boiler-Classic-Edge-Manual.pdf

Pros: electric bill went way down, fuel oil usage went to almost none. All of my heating fuel came from my own property and I got physical activity to keep fit cutting and splitting and stacking wood in the fall and spring.

Cons: cutting and splitting and stacking wood. So much wood. 12-15 cords, and these modern wood boilers need it to be nicely seasoned (so covered), split, etc. Also the cost. Also the boiler requires a largish (Taco 0013) circulator to run 24x7 when the boiler is hot to prevent the water from stratifying, which on my system was about 200 watts. Also the boiler needs fairly extensive cleaning roughly weekly and that was an annoying, dusty, sooty activity.

If I could go back in time I would have added to the apartment to the hydronic system but kept oil. If I still owned that property today and had to do it again in the face of $5 fuel oil I would be looking for an old Axeman or similar coal stoker boiler. The initial cost and weekly maintenance not to mention huge appetite for hardwood that was cut, split, and seasoned like stove wood was just too much for me.

I hope this helps.

hot_rod

Got neighbors nearby? The units will smoke when in idle mode. The new EPA regulated ones are much better, but wet, green, rotten wood is tough to burn smoke-free.

Efficiency numbers are fairly optimistic, and stated under ideal burning conditions, which rarely happens.

Factor in the cost of processing wood, clean up, fire tending time, etc. If you end up buying wood, the numbers may not pencil out so well.

I had two gasification wood boilers at my last property, it is a lot more work than advertised.

https://www.vtwoodsmoke.org/about/

leonz

You want much, much, less work than dealing with a forest eater whether is a closed system, open system or the so called high efficiency models for forest eaters.

For less money you can have an AHS S130 coal stoker boiler in a small shed placed on a concrete pad and have less work and no wading through hip deep snow to feed it at 3 in the morning AND NO SMOKE to annoy the neighbors of filter back into the home.

If you have a basement you can have the AHS S130 in the basement and also have domestic hot water at the same time.

GroundUp

I've had several of my own and have installed more than I care to remember. The hard and fast, you're not as well versed as you think you are. These are completely different animals from what you learned about in school. Almost all MFG literature is garbage unless it's a simple fan coil system. Every OWB installation is different, and requires a different design, which means a bit of custom engineering (from a competent engineer, not your average plumber/HVAC guy) for each individual system. The underground lineset selection is arguably the most important aspect of any new OWB installation, and easily 75% of those in existence are lacking in either size or quality. Something like the Thermopex mentioned above (other MFG are Rehau Insulpex, Rovanco Rhinoflex, and Urecon Pex-Flex/Logstor, there is nothing else available worth burying) properly sized for the required BTU load with the appropriate circ is the backbone of any OWB system. Screw that up, the whole system is junk.

MichaelK

Thanks guys. That is what I was looking for.
GroundUp mentioned I'd still need an engineer for the calculations and he's right. Doing all the install myself seems no fun as the pay is low (wife might buy me some beer). To clarify though, I'm not fresh from school. I'm fresh out of the field. Still centered around boilers but no longer in the service van running calls. I've worked commercial and industrial heating and cooling for 17 years. Mostly boilers and large tonnage chillers. Went to the Power Flame factory in 2012 and worked for both Trane and Johnson/York. I couldn't do the work anyway as I gave up the tools with the van and most of the tools were company. I have enough to do some light residential type repairs but that's it.

We have some wood on property but it sounds like I'd burn through it quickly. Hot Rod I live on 15 acres so the neighbors and the smoke wouldn't be an issue. However cutting, splitting and stacking wood when I have fences to mend/build, a barn to build and horses to tend to plus the wife and three kids sounds a bit time consuming. Plus most of the trees are on the property line and are walnut. Last tree crew removed some from behind our barn had to bring in a lot of equipment. 50ft plus trees. Who needs sleep though?

vtfarmer and leonz you both mentioned a coal stoker. I've seen some coal stoves in friends houses but the last coal burner I saw had a beckett mounted to the front to light it and was used for trash burning and out of service. I live in the middle of the East coast in Maryland. More to the western end. How much coal would you say you burn a year? I've heard there can be more ash to a coal fire than a wood (coming from stoves), is that true? How do you store it and yes I have a basement. Could use a small coal boiler and just use it for the first floor. Even that could cut things in half for us. House is a modular cape cod built in '07.

Everything here is electric. No oil or gas. So if the coal boiler could provide hot water as well that would be a huge bonus. I'll look into the model you suggested.

Thanks guys,
Michael

leonz

I burn six or so tons a year here in New York State. I have HEAP so that is a big help too.

Storing anthracite outside in the weather is not a problem as it is hydroscopic, having dry coal to put in the stoker is better for the hopper as it will not rust as quickly.

If you have room to shovel coal down a chute by the driveway all the better as you can have a supply of dry coal all winter if you have shoveled 4-5 tons in the basement coal room.

Back to the outside:
You can cover the coal pile with a good waterproof hay tarp from FARM TEK or GEMPLERS as long as you have heavy plastic rolled sheeting on the ground to create a moisture barrier.

You can obtain Anthracite coal in Maryland if you wish to so that is not an issue. Buying coal in bulk will save you a considerable amount of money over a long period between 22 ton truck loads versus buying in bags versus having bulk coal delivered from a local coal dealer in two ton loads.

If you need a lot of domestic hot water having a plate side arm coil on your water heater will save you lots of money as you can buy a stoker with a domestic coil in it.

I burn about 80 pounds a day in my old leaky house during the heating season and I have HEAP as kerosene for heating would have required a tank a week or more to heat this place.

You can buy bulk coal directly from the mine breaker to save money on a per ton cost and expense if you want to do it that way and have coal for four or more years on hand.

I just bag up my coal ashes in old coal bags and put the bags out with the weekly trash in regular garbage bags during the heating season so that is not a real worry for us. A lot of folks just dump thier ashes on thier dirt driveways too.

AS I said in my PM to you, I want to help you with this to avoid all the mistakes I made and made by others that I was saddled with.

Deciding on the boiler and where you intend to put it is the first step.

If you do not have a Bilco door but you have friends to bribe with pizza and beer the boiler could be lowered into the basement with a chain fall secured to a 6 by 6 butted against the basement door frame sliding it down on a set of furniture dollies lowered down on 2" by 12"s nailed to the stair treads.

If you can manage pouring a pad for a shed and a pair or three of 110 volt 30 ampere circuits for lighting and the stoker you can keep everything outside and out of the basement except for the circulators and a second heat exchanger for the heating loop for the entire home.

There are a lot of good non toxic boiler anti freezes available that are rated for well below zero temperatures that you would want to use in your system if it is in a shed outside.

Wiring the stoker using a 110 volt male plug and cord to a single separate outlet will let you run the stoker with a very small generator in the event of a power loss.

You want the best pex you can buy which is the closed cell foam pex tubing that is 15+ dollars a foot to reduce heat loss to one degree per hundred feet of pex closed cell foam tubing.

If you like you can send an e-mail to lzaharis@yahoo.com and we can go from there and I can help you with much more information and manuals and much more detailed information.

hot_rod

If you have your heart set on wood fired contact these folks

https://woodboilers.com/wood-furnace-heating-indoor-wood-boiler/

They have been selling high efficient Euro styled gasification boilers for years.

Many of the rural areas in Europe heat with this type of boiler. There are dozens of manufacturers of both solid wood and pellet boilers over there. More expensive no doubt compared to the sheetmetal barrels with a campfire beneath them, called OWF.
Built to last 30 years or more. I sold and installed several brands of these, had one in my own shop.

I suspect you have access to more wood than coal on your property or close by? Tree pros will sometimes dump you loads for free.

Zman

Don't let the OWB folks design this for you. There are tons of posts on here where folks end up with undersized pex lines, no heat exchanger, and series piped systems where the backup boiler is heating the OWB (dumping heat to the outdoors) when OWB is not running.
This has some good design info. https://idronics.caleffi.com/magazine/10-hydronics-wood-fired-heat-sources

MichaelK

zman i am a sucker for anything from caleffi not going to lie.
To go further into Hot Rods statement, most of the land around me for miles if farm. Wide open fields. Even my own is a small line of trees rimming the property line everything inside is green green horse poop,.

Looking deeper into the coal idea. Right now after recent storms and wind issues a new barn is priority. Not having an existing flue is also an issue, so unless we install one an outdoor boiler is the way to go.

The ideas, opinions, and experience of the good folks here is what I was after. For now I will continue to look into it but am holding any concrete plans on the back burner.

thanks to all
Michael

Solid_Fuel_Man

I've burned wood to heat 100% of my 3200 square foot home and DHW for 13 years. I have an indoor gasification boiler.

I had a New Yorker WC130 conventional indoor wood boiler, which is just a steel box with a water jacket. 

When I sold the New Yorker in 2012 and installed my Gasification boiler I reduced my wood usage by at least 30%. 

I live in Maine close to the Canadian border,  but have a super insulated house and burn less than 3 cord of wood annually. 

As hot rod said it is work, and a fancy gasification boiler needs dry wood. But I burn so little wood I can afford to be picky and it is easy to process 3 cord. 

There are a few OWB around here and I don't know anyone who burns less than 10 cord in them. Granted that isn't an apples to apples comparison. I wouldn't have the energy to throw that much wood into a boiler or process that much annually. 

I've rode out all the crazy oil price spikes with people burning $5000 a year, I just have to worry about filling the cars with gas.....