Wood Gasification Boilers 101

With all the uproar and banning of sales of new noncompliant OWBs here in NY, High Tech.Wood gasification boilers will become popular. Last week I completed and got my, (here's that word again) "CERTIFICATION" to sell and install an American Made woodgasification boiler. This particular line has an EPA efficiency rating of 99% and emitts 0.04lb/millBTU.
On the cover of a brochoure this looks really good, but how do they achieve these results. To put it very simple, you burn (Seasoned, Fine Split, Dry Wood) or Pellets fast and hot! The secret to their efficiency is that they don't burn 24/7. They are dependant upon thermo storage water tanks to carry the load during non burn periods. A typical burn period with the 200,000BTU/HR unit will be 4HRS. in the 26.5"L x 22"W x 28"H fire box. If know one is home to stoke this unit, you will need to increase storage tank sizing, but too big of tanks can reduce performance, if the boiler can't achieve a Temp. rise in the tank of 60F in 4 hrs. Not all the heated water in the jacket goes to the tanks. This system has a recirculation loop with a temp controlled diverter valve to maintain a jacket temp of 160F to promote clean burning. Tank sizing also has to relate to the homes heating load. This Company offers two boilers the other is a 100,000BTU/hr.
If you are looking at buying a gasification boiler, talk to a dealer who will set down with you and figure your heating load, spend time discussing your life style, so that tanks are properly sized, and the proper fuel or combination of biomass fuel is selected. These two stoves can burn Cord wood, pellets, and in the future wood chips, and be converted easily for each without tools.
If you opt to install a Gasification Boiler, you will have to do a much better job of storeing and precutting wood, split it finer. No more lunkers for the night, no snow or water soaked wood, and although it has an auto lighter, you will need much more newspaper, cardboard and kindling, as you will be lighting the wood much more often. If you are home all the time relighting isn't a problem. If you want to burn pellets, which are much more convenient and will feed and burn 24/7 if need be, or cycle through burn/nonburn periods. you will be very happy.,,

Old Dutch friend of mine, told me that in Holland during WW2, the buses and tractors were fueled with gas units like you show . I guess everything old becomes new again.

We have an HS Tarm gasification boiler that was here when we moved in ten years ago. It is thermostatically controlled so that when the water temp reaches 200 the fan shuts off and the fire stops burning and sits. When the temp drops the fan comes on and the fire takes off again within a few minutes, even if the fan has been off for several hours. We do indeed have to cut wood several months in advance and store it under roofs, but it is well worth it in my opinion. It was made in Holland, I think, and the nearest dealer is in NH but they are very quick at shipping parts when something is needed and we have a kerosene boiler for backup. We burn about 23 standard cords of hardwood a year to heat a converted barn that is about 35x80 and three stories, plus it makes all of our domestic hot water. Best of luck with your new career option.
Zach

Like Zachary, I also have a HS Tarm wood fired boiler. I installed this one in 1977. It is approximately 120,000 BTU/hour. I think the burn chamber is 1/4" thick boiler plate. It has a 28 gallon submerged domestic water tank which I use to preheat the HW going into the electric domestic HW tank. My house is a story and a half cape cod style, plus full walkout basement. At times we have had electrical power failure at subzero temps, the piping and boiler water will thermosiphon, keeping the house in the mid to upper 60's until the power is restored. There are 5 separate zones with double loops and a lot more radiation than normal, so I can distribute water at 130 F and feel quite comfortable. The system is dead silent, even if the distribution pump is running. This boiler predates the wood gassification models, but it sure has been good to us. BTW, Tarm is a Danish company. The "HS Tarm" was the inventor/manufacturer's name, Hans Sorensen Tarm. I have a 7" masonry, red clay liner chimney which I run the brush through 2 X per winter. I have a ladder permanently bolted to the roof to enable me to get to the chimney in icy conditions. And yes, it likes ONLY DRY WOOD. I find that dry Elm works beautifully with less creosote than dry Oak.

Wood fired boilers are not for everyone. It does become a lifestyle choice. But mine has an oil gun for when we are away or maybe sick. I doubt the oil fired chamber is very efficient, maybe even very poor efficiency. So I burn mostly wood.

Paul in MN

My neigbor was in ww2 and part of the clean up of germany and the holocaust once the war ended. He said the trucks the germans gave then to use would use this method to fuel there trucks because all of the fuel depots were destroyed in the war.