Replacing Brookwood boiler: Gasifier vs a "conventional"?

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Currently have a "indoor boiler" that is essentially a steel box with a L shaped tank on top, looks like this:
Replacing Brookwood boiler: Gasifier vs a "conventional"?

Air inlet is in the back, has what appears to be a Samson draft regulator to open/close the air inlet based on water temp:
Replacing Brookwood boiler: Gasifier vs a "conventional"?

Air then comes up to the front in the tubes above the firebricks (rectangular tubes L and R above the firebricks), there is a "chimney" in the back with a damper that forces smoke to go down to 4" from the floor before going out to the chimney (damper open in this picture):
Replacing Brookwood boiler: Gasifier vs a "conventional"?

What's left of the label says Brookwood Wood Heating Systems, IIRC it used to say 210k BTUs:
Replacing Brookwood boiler: Gasifier vs a "conventional"?

Positives to it:
  • Huge firebox (door is 24x24, 28" deep)
  • Burns hot
  • Can burn most anything
  • Never get more than a pint of grey/brown ash out of the chimney when cleaning it out
  • Needs work:
    • The "chimney" in the back of the firebox is burnt out in the front, needs a 8"x8" piece welded in to replace what has eroded away
    • The "Additional air" tubes (vertical tubes seen in the back of the picture with a fire going) need to be cleaned out and/or replaced, they currently are plugged up with ashes (due to the chimney being eroded and letting wood get to them)
    • Top and tank are warped, not sure how big of an issue this is, other than there is not metal to metal contact for good heat transfer
    • Needs a tank (or other heat capture device on the right side), that gets up to 500-800F when a fire is going and while its not wasted heat, I would rather put the heat into the water, not into the air)
  • No place for ashes to seperate out from the wood, the ashes build up on the bottom and you have to rake/sift through them to get "mostly ash" out and keep the cinders/coals in the stove
  • Needs a new draft regulator, or this one reworked as the plastic knob is flaking apart
  • Uses a lot of fuel (a 5'x4'x22" pile of wood every day)
The rest of the heating system is a Valliant F100-40 HE boiler (Net 113 MBH) with a Riello oil gun feeding 2" steel pipes that go to cast iron radiators and copper tube finned baseboards in a single zone (yes, there are plans to fix that).
The Brookwood has an aquastat that turns on its circ pump and pumps hot water through the Valliant once its up to temperature so when the thermostat calls for heat, the Valliant circ pump turns on, but does not fire the oil boiler.

This is in a ~2200SF farmhouse that in Upstate NY that has been added onto several times (ironically, the additions are more drafty than the original farm house).
Tentative spitball plans for upgrades include:
  1. Replace the copper baseboards with cast iron radiators (have the radiators, just need time and fittings)
  2. Split the system into zones
    1. Either "old house" and "new house" or "old house up", "old house down", "new house up" and "new house down"
    2. Replace the piping in the basement with manifolds and PEX-AL-PEX
    3. Add thermostats or sensors in the rooms to control the zones
    4. Convert "new house down" (Kitchen/Dining area) to radiant floor
  3. Upgrading insulation
    1. Replace/add to blown in insulation in the walls
    2. Replace attic insulation (possibly foam the underside of the roof deck and make the attic a conditioned space)
  4. Possibly replacing boilers
    1. Replace the oil boiler with a propane condensing one (MUCH cheaper per BTU of heat, oil boiler needs some gaskets and oil is expensive)
    2. Repair or replace the wood boiler with something "better"
Parts on hand:
  • Various cast iron radiators (bought them from someone who was converting to forced air), all passed a pressure test and have been repainted
  • Taco 4 zone controller
Grew up with wood forced air heat, liking having radiators, a my brother has a Alternative Heating Systems Woodgun that he is working on putting together (slowly converting the house from forced air to hot water heat).

Any downsides to a gasification boiler (other than needing storage)? I see several Tarms for sale, but they are $2000-3000, are 20+ years old, have "regular" steel fireboxes and given the concerns of fireboxes rusting out (per Scott when I called him about one), I dont want to spend that much on a gamble.

I see several "conventionslish" used boilers in the $500-2000 range, but am unsure how much of an improvement they would be over what we have.
They are:
  • Harman SF240 (several other SF models as well) - Seems like lots of reviews talking about them being hard to control and inefficient as well as making a lot of creosote
  • "Biasi wood boiler" - Cant find much on them, some seem to say that they make a lot of creosote
  • Glenwood 7040P boiler- Cant find much on them

Thinking that with the re-plumbing I would:
  • Run a main circ loop with a pump
  • Have the boiler(s) plumbed with closely spaced tees and a circ pump for each boiler so they are independent
  • Setup pressurized storage where the oil tank is now (if I get a gasifier and switch to propane)
We have a small farm and always have blowdowns in the woods that need to be cut up no matter what so spending a little on wood makes some sense.
I have the knowledge and tools be able to cut/thread steel pipe, solder copper, crimp ProPress fittings, wire everything up and I have friends who have put in (and more importantly diagnosed/fixed poor installs) for more than a few propane boilers, but they dont deal much with wood boilers.

I guess it boils down to between:
  • Harman SF series
  • Biasi wood boiler
  • Glenwood 7040P
  • Tarm Excel 2000
Are there any big negatives to any of them for wood?
Anything I should plan/prepare for before I dive in and start rebuilding things?

Thanks for reading my wall-o-text.

Aaron Z
Gasifiers do not work very well without storage and much of their efficiency goes away without storage.
Since you are in New York and probably paying for it somehow, this free course is worth the time. NYS has or had a fairly generous subsidy for biomass heating if installed correctly and paid for John Siegenthaler to develop this course to make sure people were doing it right. Time well spent.
Thanks for the link, the problem I see (looking into their requirements) is they requite ALL new parts and a certified installer.
This will be a DIY install with a used wood boiler and either industrial surplus pressure vessels (about $1-1.5/gallon), or repurposed and cleaned propane 300 gallon propane tanks (about $2/gallon plus the time to clean them).
If I had to spend the kind of coin that a new gasifier and storage would cost, I would just use a propane condensing boiler as it wouldn't be worth it to me (someone I know was quoted $42k to replace his Tarm and add the storage that is now required).
Even for a propane boiler, the quotes I got last year were $9-12k vs the $3-5k that my friends spent on their installs (same make/model boiler, just DIY vs a company).
That is not to say that I won't be following the principals outlined in that course, just not putting it in for reimbursement from NYS as the reward would not be worth the additional cost.

Aaron Z
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If you replace, definitely go gasifier and storage. It’s worth the extra cost, IMO. Check out the Switzer boiler,it has integrated storage so no plumbing in extra storage/boiler protection. It may not work for your install as they are big and you’d be going on a basement? Also probably wouldn’t find a used one, as the people that have them are satisfied and don’t want to get rid of it.
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I am not pushing you to towards the rebate, I just wanted you to see the current best practice.
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If you replace, definitely go gasifier and storage. It’s worth the extra cost, IMO. Check out the Switzer boiler,it has integrated storage so no plumbing in extra storage/boiler protection. It may not work for your install as they are big and you’d be going on a basement? Also probably wouldn’t find a used one, as the people that have them are satisfied and don’t want to get rid of it.
That would probably be too tall, the door into the basement is 48" wide, but I don't think it is 60" tall.
I like the idea though.

Aaron Z
Someone just posted a Tarm Solo plus (osrsomething quite close) in the for sale forum that may fit your bill. Plenty of happy folks out there with Tarms. Its last of the Tarm's imported although I think at that point they were made by another firm Scandtec and labeled as a Tarm. Tarm USA still supports them with parts

Its going to be 1000 plus pounds. Looks like 55-1/2" high.
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Just FYI- Gary Switzer will custom build them to your specs.
I'm sure he would for a price :eek:
Took a tape to the door opening, it's 38x60, could make it 48" wide if needed with a few hours work.
Not presently in the plans to buy a new one though, but it's worth thinking about for "phase 2" (a planned addition for an inlaw suite) which will greatly reduce the amount we will need to handle wood (the plan is for a basement with a door setup so we can bring totes of wood in with a pallet jack and moving the wood boiler to that end of the basement so we can split into totes and not touch the wood again until we put it in the boiler).

Aaron Z
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Well, had a 2001ish Tarm Excel 2200 follow me home today (more got dragged home):
Replacing Brookwood boiler: Gasifier vs a "conventional"?

Came off of the trailer with the loader WAY easier than it went on.
Time to see if the back wall of the firebox is solid enough to weld up the pinhole leak and run it, or if it is going to the scrapyard...

Aaron Z