Hello, very new to the forum and hoping for some guidance. We are looking at replacing our old wood boiler. It was an old engine converted to a stationary boiler for heating that is on 3" pipe with a circulator. It is getting to the end of its life and we are looking for something a little more efficient. We heat a large 1930's building. Approx 5,000 square feet per floor with 3 floors as well as 1 house of about 1500 sq feet. We are estimating between 750k and 1 million btu would be needed. We have spoken to several companies and are looking for suggestions. Central Boiler (Edge 960), Portage and Main sent info but nothing specific but we have seen a large unit from LS Bilodeau (LS 950) as well. We also looked at the Log boiler. Anyone have suggestions or experience with large boilers? Thanks!
Large Boiler
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hobbyheater
Minister of Fire
Garn builds a boiler in the range you are looking for the Garn 2000 and the Garn 3200 ,and Switzer will custom build . Switzer is pressurized and Garn is not.
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Quite the impressive piece of equipment. You are in tough spot as handing the volume of cord wood required to keep that fed at full load requires nearly a full time tender to keep the boiler loaded plus a lot of handling. I would be careful on estimating the heat demand for the system, that boiler was not designed for efficiency, my guess is there are lot of losses that a new installation would not have. With a load like that, a small automated wood chip boiler might be a better fit like a Messersmith. https://burnchips.com/products/automated-outdoor-wood-boiler. The problem with wood chip boilers is they are very dependent on chip quality, if the chip quality is poor, the automated feeders clog up. Ideally the wood chips come from the trunks of trees (boles) or sawmill rejects with none of sticks and twigs that come with whole tree chips. Froling in NH sells Precision Dried Chips which have a higher BTU content and a lot more uniform but unless there is similar facility near you, it may not be an option. https://www.frolingenergy.com/wood-chips
In most cases for a system that size, the solution is a wood pellet boiler. They are quite popular in Maine, NH and VT for commercial and small institutional facilities. They usually have silo or bin that is bulk fed from a bulk pellet delivery truck. Depending on the supplier of the boiler and the feeder system they may be set up to burn a lower costs commercial pellet than the grade A pellets typically used in homes. I think most of them arond me use the grade A pellets because that is what the suppliers stock.
The alternative might be to buy and install multiple boilers and stage them as needed. A large boiler operated at low load is even less efficient and quite dirty. Running one smaller boiler at high load will be far more efficient and clean although with a steam based system the option of thermal storage is not viable. In most cases the right fix is to swap the building over to hydronic based heating and install a large thermal storage tank in conjunction with dual or triple pellet boilers. I have seen that done in a couple of old schools converted to housing and few government plans.
In most cases for a system that size, the solution is a wood pellet boiler. They are quite popular in Maine, NH and VT for commercial and small institutional facilities. They usually have silo or bin that is bulk fed from a bulk pellet delivery truck. Depending on the supplier of the boiler and the feeder system they may be set up to burn a lower costs commercial pellet than the grade A pellets typically used in homes. I think most of them arond me use the grade A pellets because that is what the suppliers stock.
The alternative might be to buy and install multiple boilers and stage them as needed. A large boiler operated at low load is even less efficient and quite dirty. Running one smaller boiler at high load will be far more efficient and clean although with a steam based system the option of thermal storage is not viable. In most cases the right fix is to swap the building over to hydronic based heating and install a large thermal storage tank in conjunction with dual or triple pellet boilers. I have seen that done in a couple of old schools converted to housing and few government plans.
brenndatomu
Minister of Fire
PassionForFire&Water
Minister of Fire
Check Heizomat wood chip boilers for commercial use.
Fully automatic chip feed and deashing.
Starting at 200,000 BTU/hr. up to 3,420,000 BTU/hr.
UL/CSA listed
ASME certification available 45 psi/225F
Hot water boiler
Fully automatic chip feed and deashing.
Starting at 200,000 BTU/hr. up to 3,420,000 BTU/hr.
UL/CSA listed
ASME certification available 45 psi/225F
Hot water boiler
Thanks for all the info. We will definitely look at these. As we have large quantities of wood we would like to stay with cord wood if possible but nice to know our options. Sorry, to clarify we aren't using steam anymore. We use cast rads in a hydronic system.
salecker
Minister of Fire
Looking at your boiler one would expect it to never die
There is a lady whose husband did the same thing up here with a boiler from a padlewheeler that still is being used to heat her house and other buildings
There is a lady whose husband did the same thing up here with a boiler from a padlewheeler that still is being used to heat her house and other buildings
It is still very repairable. Although, it is getting harder and harder to find someone to fit new tubes. Boiler plate is getting thin and welding is an issue. I think "dying" has more to do with we are tired of firing every 2 to 3 hours and burning through the better part 100 cord per year. As a single pass boiler it is very inefficient.
Switzer makes a good, efficient boiler. I can’t speak for Garn, not having used one. I have a Switzer and it’s a great boiler, I wouldn’t hesitate to buy one again. If you are considering a Switzer, your best bet is to call Gary Switzer and talk to him.
That’s quite a piece you have there.
That’s quite a piece you have there.
Any open boiler that does not build pressure is going to need continuous feedwater treatment and testing If that is not done they rust out. Search for Garn on this site and you will see folks who have internal rusting issues that most likely caused by water chemistry.
It is a beast. Has done the job for many years. We will definitely reach out to Switzer. Thanks.
Switzer systems are under 30psi, so that should work well.
Here’s some info on mine.
https://www.hearth.com/talk/threads/my-switzer-install.189820/
http://Thread 'My Switzer install'
https://www.hearth.com/talk/threads/my-switzer-install.189820/
http://Thread 'My Switzer install'
sloeffle
Minister of Fire
Do you buy logs by the semi load and process them with a wood processor ? I couldn’t imagine handling that much wood in a year.
hobbyheater
Minister of Fire
Not trying to steal your thread but trying to make a point.
My first boiler was like this one - it burned 22 cords in one year
A good gasification boiler with storage was able to heat the same house and domestic hot water on 4 cords a year for over 40 years. That's a lot of wood!
When you go to gasification with storage and good under ground lines, you will likely see a similar savings in wood consumption that could be high as 80%.
The down side to running a gasification boiler is that it needs dry wood - 15% to 25 % moisture content.
If you're only going to be burning 20 to 30 cords as opposed 100, it should not be hard to do!
My first boiler was like this one - it burned 22 cords in one year
A good gasification boiler with storage was able to heat the same house and domestic hot water on 4 cords a year for over 40 years. That's a lot of wood!
When you go to gasification with storage and good under ground lines, you will likely see a similar savings in wood consumption that could be high as 80%.
The down side to running a gasification boiler is that it needs dry wood - 15% to 25 % moisture content.
If you're only going to be burning 20 to 30 cords as opposed 100, it should not be hard to do!
I would stay with a closed system. All the cracked factory welds I have had with my Garn. I would stay away from them. When I bought my Garn it came down to a Switzer or a Garn. I made the wrong choice and bought a Garn. Don't repeat my mistake. I have spent a fair amount of money on my Garn with repairs and chemical to treat the water.
I had the opportunity to help with testing a prototype jumbo version of the University of Maine "worlds most efficient" wood boiler forty years ago. It was installed at a large university greenhouse complex in Greenbush Maine. It had a large thermal storage tank in the 10,000 gallon range. We had to do an efficiency run consisting of weighing and timing how many pounds of wood had to be fed in the unit, while recording the temperatue sire of the thermal storage. I think it was 40 pounds every 20 minutes. Once the tank was warmed up it was good for several hours. My guess is it was at least twice the efficiency of the OPs boiler.
It definitely needed an automated stoker feeder but that is tough with non uniform wood. It was an ideal setup for one as the water cooled jacket on the feed end and induced draft fan meant no puffbacks. I have no idea how long it ran but my guess is the labor required to feed it would have made it uneconomical to run long term. Long ago I saw a stoker feeder designed to use plywood cores that are a byproduct of the plywood industry. The cores were hardwood and looked like they were turned on a lathe of varying diameters. No bark and a lot more uniform than cordwood. I dont think any commercial firm makes a stoker feeder for fire wood as it would only make sense for a large boiler but it would a be fun project. A lot easier for wood chips as wood chip stokers are commercially available and I have worked on several large ones for power boilers as its basically coal technology developed over the coal era.
It definitely needed an automated stoker feeder but that is tough with non uniform wood. It was an ideal setup for one as the water cooled jacket on the feed end and induced draft fan meant no puffbacks. I have no idea how long it ran but my guess is the labor required to feed it would have made it uneconomical to run long term. Long ago I saw a stoker feeder designed to use plywood cores that are a byproduct of the plywood industry. The cores were hardwood and looked like they were turned on a lathe of varying diameters. No bark and a lot more uniform than cordwood. I dont think any commercial firm makes a stoker feeder for fire wood as it would only make sense for a large boiler but it would a be fun project. A lot easier for wood chips as wood chip stokers are commercially available and I have worked on several large ones for power boilers as its basically coal technology developed over the coal era.
sloeffle
Minister of Fire
Years ago I stumbled across a European gasification boiler that would feed itself. On the right hand side there were some chains that you would put the wood in and it would dump the wood into the top of the boiler. The site was in German so I couldn't read the specs etc but each piece of wood look pretty uniform so I'm sure there were some requirements around wood size and length.
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