Well here it is. After years of planning and budget cuts, I've fabbed up a functional wood boiler with pressurized storage on a budget. I'm not a plumber by any means so easy bashing. I heat a new 2000 square foot ranch with traditional insulation(no foam) and 1200sq foot garage to 45F. I use new style wall radiators and a few loops of in floor heating(high temp). I have a 8x12 enclosed boiler room behind garage that feeds hot water to 1000g storage tank in basement. Upon satisfied aquastat located on storage tank top, zone call and boiler loop zone valve open, water will be drawn from tank top to LLH, and then to zones. Once tank top temp is lowered below 140 or so, aquastat opens and DPDT relay swaps from storage tank pump to wall hung gas boiler that came with house. Low loss header provides different flow of zone pump and tank draw pump.
Hydrophore style expansion tank as of right now with pex gauge glass. Top of hydrophore is pressed up with compressed air. I've added a little bit of nitrite to help slow down corrosion on inside of pipework. The system is closed and have not had to add any water this season. When tank temp is at 70 degrees throughout, system pressure is 11psi at basement level and 8 psi at boiler level. Estimated 5 psi minimum at highest point in system. Once fired and tank temp bottom and top reach 200, pressure is at 17psi at basement level.
As far as the boiler(s): I used 2 tasso cast iron triple pass wood/coal natural draft units, and made one. One of which is rated at 87kbtu with only a depth of 18 inches, I added 2 more sections from boiler 2. Making it approx 116kbtu/hr, or something near that I believe, and 26" deep. It uses a samson thermostatic damper controller. I have a UPS and deep cycle battery in basement that runs loading unit when power goes out. UPS will run the loading pump for about 8 hours. Typical burn time from completely full to empty is about 6 hours, approx 6 inch max dia wood filled to the brim.
Loading unit LK810, feeds tank in basement. I plan to upgrade this with danfoss valve and 3 speed grundfos. There's a lot of head in the system and the 810 is not rated for a lot of resistance in pipework. With the 810 on high speed, during high temp firings, I can have 20degreeF difference from inlet to outlet when thermostat valve is wide open.
Storage tank is an old 1000g propane tank that I've fitted 3 inch inlet/outlet pipes to to assist with strat. I used a remote BBQ thermometer setup to monitor tank temps. Stratification is amazing. I insulated the tank with blown in insulation. When tank temp is at 200F, top of ply wood will reach about 69F, with a basement temp of 66. I went on vacation once for a week with tank temp at 139 on the second day, at day 6, the tank hadn't dropped 1 degree, so I think the insulation is working great.
I've burned approx 30 gallons of propane this year and about 5 cords of dry mixed hardwood. One firebox burn will last the house a day or two during normal Jan/Feb days. It also heats my potable. Super happy so far!
Pros: convenience(I need a firebox full a day, but can miss 1 day, which then I need to have 1 fire and a refill), initial cost, no switching wood boiler on/off, already had low loss header with 1-1/4" taps ready for secondary heating system, once boiler is providing hot water - it can be used to heat(no waiting for tank temp to rise). Lighting is a breeze - takes about 3-4 minutes to load, light and leave it. Should get by with 1 fire per 4-7 days(guess) during the summer for domestic HW.
Cons: poor wood boiler efficiency, creosote at chimney cap(3 years undercover dry wood), LK810 does not have enough flow with tank being so far away from boiler, not the prettiest setup I've seen. Slightly concerned with expansion tank and detrimental long term effects. Once o2 has depleted, I think it should operate as any other closed system, but time will tell. I also ran a lot of black iron, if I did it again, I'd run all pex, too many man hours threading pipe. Electrical work was a bit troublesome, I bypassed the use of any plc's and used 110v relays which worked amazingly well, but it would take Einstein a few hours to figure out how I've run the circuitry. I also could have saved a bunch of money by running 1" pex/pipe rather than 1-1/4". My plumber said that I would need the big pipework to move the heat out of the wood boiler, but really I could easily get by with 1" in my current setup.
Parts list and prices:
0 Boiler1
150 Boiler2
600 LK810 loading valve
400 Tank and pipework
400 Tank walls/sheathing and insulation
700 Underground insulated pex o2 barrier
1200 Other pipework/vents/fittings/valves/strainers to/from LLH
420 (2) Viridian VS circs
380 Additional zone valve controller, aquastat for tank, zone valve, check valve, timer relay and DPDT relay
120 UPS and battery
I may have missed a few things, but for the most part build comes in around $4500.
I'd like to eventually put a Varm in place of "old smokey". This summer I'll be pulling the LK810, and installing a danfoss valve and bigger pump for better water flow.
The schematic is not quite up to date. No dump zone as I've used a UPS. No B valve, as there's just a spring check there that holds water in boiler when tank pump starts.
I had to throw in a pic of my beautiful supersplit, repowered with Honda 5hp, she holds a piece of my heart.
I'd like to thank all of the wood boiler nuts on here for the insight. About 95% of my howto came from hearth.com forums.
Hydrophore style expansion tank as of right now with pex gauge glass. Top of hydrophore is pressed up with compressed air. I've added a little bit of nitrite to help slow down corrosion on inside of pipework. The system is closed and have not had to add any water this season. When tank temp is at 70 degrees throughout, system pressure is 11psi at basement level and 8 psi at boiler level. Estimated 5 psi minimum at highest point in system. Once fired and tank temp bottom and top reach 200, pressure is at 17psi at basement level.
As far as the boiler(s): I used 2 tasso cast iron triple pass wood/coal natural draft units, and made one. One of which is rated at 87kbtu with only a depth of 18 inches, I added 2 more sections from boiler 2. Making it approx 116kbtu/hr, or something near that I believe, and 26" deep. It uses a samson thermostatic damper controller. I have a UPS and deep cycle battery in basement that runs loading unit when power goes out. UPS will run the loading pump for about 8 hours. Typical burn time from completely full to empty is about 6 hours, approx 6 inch max dia wood filled to the brim.
Loading unit LK810, feeds tank in basement. I plan to upgrade this with danfoss valve and 3 speed grundfos. There's a lot of head in the system and the 810 is not rated for a lot of resistance in pipework. With the 810 on high speed, during high temp firings, I can have 20degreeF difference from inlet to outlet when thermostat valve is wide open.
Storage tank is an old 1000g propane tank that I've fitted 3 inch inlet/outlet pipes to to assist with strat. I used a remote BBQ thermometer setup to monitor tank temps. Stratification is amazing. I insulated the tank with blown in insulation. When tank temp is at 200F, top of ply wood will reach about 69F, with a basement temp of 66. I went on vacation once for a week with tank temp at 139 on the second day, at day 6, the tank hadn't dropped 1 degree, so I think the insulation is working great.
I've burned approx 30 gallons of propane this year and about 5 cords of dry mixed hardwood. One firebox burn will last the house a day or two during normal Jan/Feb days. It also heats my potable. Super happy so far!
Pros: convenience(I need a firebox full a day, but can miss 1 day, which then I need to have 1 fire and a refill), initial cost, no switching wood boiler on/off, already had low loss header with 1-1/4" taps ready for secondary heating system, once boiler is providing hot water - it can be used to heat(no waiting for tank temp to rise). Lighting is a breeze - takes about 3-4 minutes to load, light and leave it. Should get by with 1 fire per 4-7 days(guess) during the summer for domestic HW.
Cons: poor wood boiler efficiency, creosote at chimney cap(3 years undercover dry wood), LK810 does not have enough flow with tank being so far away from boiler, not the prettiest setup I've seen. Slightly concerned with expansion tank and detrimental long term effects. Once o2 has depleted, I think it should operate as any other closed system, but time will tell. I also ran a lot of black iron, if I did it again, I'd run all pex, too many man hours threading pipe. Electrical work was a bit troublesome, I bypassed the use of any plc's and used 110v relays which worked amazingly well, but it would take Einstein a few hours to figure out how I've run the circuitry. I also could have saved a bunch of money by running 1" pex/pipe rather than 1-1/4". My plumber said that I would need the big pipework to move the heat out of the wood boiler, but really I could easily get by with 1" in my current setup.
Parts list and prices:
0 Boiler1
150 Boiler2
600 LK810 loading valve
400 Tank and pipework
400 Tank walls/sheathing and insulation
700 Underground insulated pex o2 barrier
1200 Other pipework/vents/fittings/valves/strainers to/from LLH
420 (2) Viridian VS circs
380 Additional zone valve controller, aquastat for tank, zone valve, check valve, timer relay and DPDT relay
120 UPS and battery
I may have missed a few things, but for the most part build comes in around $4500.
I'd like to eventually put a Varm in place of "old smokey". This summer I'll be pulling the LK810, and installing a danfoss valve and bigger pump for better water flow.
The schematic is not quite up to date. No dump zone as I've used a UPS. No B valve, as there's just a spring check there that holds water in boiler when tank pump starts.
I had to throw in a pic of my beautiful supersplit, repowered with Honda 5hp, she holds a piece of my heart.
I'd like to thank all of the wood boiler nuts on here for the insight. About 95% of my howto came from hearth.com forums.
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