Wood Stove Uses Firebrick To Boost Efficiency

Wood Stove Uses Firebrick To Boost Efficiency WOOD STOVES/FURNACES Wood Stoves/Furnaces (20L) 29-5-17 Hans Nicolaisen of Waldoboro, Maine is very happy with the new wood stove he designed and built. It's basically a small masonry heater with a steel skin, he says. "This is something anyone with a small shop can build. All they need to make a very efficient stove is some firebrick, steel plate, steel bar for the grate, a damper, and tubing or pipe for the secondary air tube," he says. Key to the stove's success is that the firebrick inside stores the fire's heat and also allows you to make the fire as hot as possible. "The main thing is to keep the fire hot, even if it's small. You can't keep the fire or coals hot if the fire is losing its heat," explains Nicolaisen. "This furnace lets you build a short hot fire and then release the heat slowly over time." He says that building a true masonry furnace requires a high degree of skill that even most ordinary masons don't have. But in his stove, all of the firebrick is "dry-stacked" with no mortar. "I work in steel because I'm not a mason, but my stove provides many of the advantages of a masonry heater," he says. "To truly appreciate it, it's important to understand the concept of masonry heaters. The main thing is to have the fire burning inside the firebrick firebox. The more firebrick you have, the more heat you can store." Nicolaisen points out that dampers are really important if you're storing heat in a large mass where it will be radiated to the outside of the firebox. To do this, it's important to stop the heat from escaping out the chimney, he says. "I put the stove in my house last December and it worked very well," Nicolaisen says. "It heats more evenly than a regular wood stove and uses less wood. It's designed so it can be easily taken apart to reconfigure the brick. This is important, because once you have built the stove, you learn from it and have new ideas to make it better." Also, because the stove has 1,100 lbs. of firebrick in it, it has to be assembled after the shell (the steel skin) is in place in the house. The completed stove weighs around 1,400 lbs. Nicolaisen says stove builders should give some thought to whether the floor will support the extra weight. After a year's use, he says the new stove uses about 20 percent less wood than the wood stove it replaced. The stove's body is 4 ft. tall and about 2 ft. square. Those dimensions are based on the size of standard firebrick (9 by 4 1/2 by 2 1/2-in.) so that the cutting of firebrick is minimized. The firebrick that does need cutting can be handled with a chop saw using a good abrasive masonry blade, he says. Nicolaisen has been heating and cooking with wood since 1968 and designing and building stoves for himself and occasionally for friends since 1975. "I will be putting together plans for my new wood stove. People who are interested can also pick up a book by David Lyle called "The Book of Masonry Stoves," which would give them far more information than I can hope to give." When asked how long it took him to build the stove, Nicolaisen says, "I suppose, in a way, it took me thirty years to build it, because of all the learning from trial and error that went into it. In reality, it was about two weeks. The cost of the steel, firebrick, and odds and ends was about $700. It was all new steel and firebrick." Today, Nicolaisen is busy operating his business, "Nick's Welding," where he specializes in making dampers for masonry heaters. Contact: FARM SHOW Followup, Hans Nicolaisen, 3005 Washington Rd., Waldoboro, Maine 04572 (ph 207 832-5350; hansn@adelphia.net).

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