GARN Boiler

I often have people ask me about my heating system so I have added a few pictures. According to the manufacturer and the only authorized dealer here in Alaska, I am the only owner of a personal GARN boiler system in Alaska. There are about a dozen now in operation in Alaska but they all serve villages, schools, businesses, and community centers.

The GARN is a wood fired boiler built into a 2000 gallon steel tank surrounded by about 1800 gallons of treated water. The boiler is designed to burn the wood extremely hot and fast, which increases efficiency and decreases creosote. In the ceramic core the temperature will reach about 2000 degrees. The flue gasses then make 6 passes through the water in the tank before exiting the chimney at between 300-500 degrees. The water in the tank heats up and stores the heat for use later. I load the boiler with 3 foot long un-split logs with a few dry pieces of kindling and dry bark to help start the fire. Its takes about 5-7 minutes to load the boiler and light it. But then I get to walk away and the boiler does the rest. I burn a mix of any local wood I can get for free or really cheap, which includes cottonwood, birch, spruce, willow, and alder.

The GARN boiler occupies a small room about 12 feet X 7 Feet. My house is about 5000 square feet which includes 1000 square foot basement and 1000 square foot garage. I framed the house with the exterior walls double walled with staggered studs. Essentially I built 2x6 walls and then 2x4 walls inside with a 1/2 inch gap between the walls. The studs were staggered so there was less thermal transference from stud to stud and out the wall. Both walls were insulated giving it about an R34 in the walls and then an R70 in the energy saver trusses. Every room of the house has radiant in-floor heat and is controlled by 7 zones that can be adjusted to preference.

The basement is wrapped in 4 inches of blue-board foam with 3 skirts extending 2 feet out at a 70 degree angle to the wall.

I currently burn about 10-12 cords of firewood a year. This provides the heat for all 5000 square feet (kept between 68-72 depending on the room) and the domestic hot water from the end of August through May. Unfortunately from end of June-Aug the heat from the boiler makes the house too hot to be used effectively for only hot water those 3 months and we currently resort to Electric or Oil heat depending on the cost of fuel VS KWH.

It’s the middle of October and I currently only fire-up the boiler once every 2 days. In the middle of winter I usually have one fire a day unless it drops down to below -20 and I haft to double load or have a fire every 18 hours or so.