Wood heat is an inexpensive alternative to many other heating methods. It can also compliment electrical heat and save on your powerbill. However, when using wood heat from a wood stove it is best to take some precautionary measures.
Wood stove safety really begins with the installation and selection of your woodstove.The first step is being sure that you have the correct size wood stove for your home. To find out more on how to select the right size woodstove read:
How do you know what size wood stove you need? The reason you need to have the correct size stove is that a stove that is too large can cause creosote build up resulting in a chimney fire. A stove that is too small can overfire, which can result in walls and other flammable materials that are a "safe" distance from the stove to ignite.
Once you have chosen the woodstove that is appropriate for your home, you will want to be sure that it is correctly installed. Some installation instructions from
http://www.motherearthnews.com/Do-It-Yourself/1980-01-01/Wood-Stove-Safety.aspx?page=2 follow:
Your first concern when installing a wood stove is to maintain safe clearances. Follow the specifications in the accompanying tables, and—if you have a limited space for your stove—use suitable thermal barriers to safely reduce the clearance distances. Note that the National Fire Protection Association (NFPA) specifies asbestos millboard—not cement board—and/or steel plate. But, MOTHER hopes that—because of the harmful effects of asbestos—conscientious readers will opt for steel and an adequate air space.
Moreover, when your wood stove's body is set at least 18 inches above a flammable floor (or even if the framework
supporting this surface can burn), line the floor—both under and near the heater—with 24-gauge sheet metal. If the clearance is less, however, use four inches of hollow masonry
underneath the metal.
Of course, the positioning of your stove will determine the amount of stovepipe necessary to connect it to your chimney. The NFPA specifies that as little stovepipe as possible should be used. However, it's generally accepted that every four feet of pipe (up to about 12 feet) that's exposed to inside air space will yield about 10% "bonus" heat from a stove. Uninsulated stovepipe does an excellent job of radiating the heat from flue gases.
However, beyond the obvious danger of someone's being burned by the hot metal surface, there are two other basic hazards connected with using an extended stovepipe. First, as the pipe's length increases, so does the possibility that its joints will break during a chimney fire.
And then there's the question of whether the heater's
draft is adversely affected by a long stovepipe. You see, the heat of the flue gases is dissipated through the metal, and this
does reduce the thermal draft effect . . . but longer sections also tend to
improve draft by increasing the chimney's volume. The trade-off (as well as the point where one effect overwhelms the other) is an uncertain one.
The uninsulated stovepipe should clear all flammable objects by the same distances suggested for stoves in the tables of clearances. Again, you can reduce the necessary space by using a thermal barrier. It's also possible to use insulated factory-built chimney (with clearances as specified by the manufacturer), but—if you do so—you'll lose much of the heat you would have gained from the stovepipe. (Plus, the factory-built product can cost around $1.50 per linear
inch, while regular stovepipe currently sells for about $1.50 per linear
foot!)
Most wood-heating veterans now recommend that the female ends of the pipe sections be mounted upward ... to prevent creosote from leaking out around the seams. However, there is still a small counter-current philosophy which believes in setting the female junctions downward ... to keep smoke from escaping. A safe compromise is to mount the female ends up ... and then seal each junction (except those joints which facilitate removal of the pipe for cleaning) with furnace cement and three sheet metal screws spaced around the circumference of the joint.
The NFPA also specifies that all
horizontally run stovepipe should rise (away from the stove) at least 1/4 inch per linear foot. Again, not all stove experts agree on this point. The basic idea behind the steady-rise stipulation is that the flue's draft will be aided by the slight upward flow. Whether or not this
actually is the case, it's an easy enough requirement to follow . . . and a little
extra safety never hurt anyone.
Should you decide to use an extensive run of stovepipe, support the tubing (usually by suspending it with wires)
at least once every six feet. In addition, always try to employ a minimum number of bends—using the most
gradual curves possible—to reduce turbulence in the exhaust gases.
Remember, too, that even the most skillfully fitted and maintained stovepipe has a
maximum lifespan of three years. After the first season you should check your pipe for soundness regularly. You can make a fairly accurate test by squeezing the pipe in your hands. If you are able to crush the walls in your grip, the corrosive creosote has eaten away too much metal for the installation to be safe.
(One useful capability—that you can build in when you install your heater—is a crud trap. Where the pipe leaves the stove—in most cases, horizontally—simply add a tee fitting instead of an elbow. Then plug the lower end of the tee with a removable cap that's fastened with sheet metal screws. When the time comes for cleaning or inspection, this opening will give you easy access to a section that is usually the longest straight run of
stovepipe.)
Read more from Mother Earth News at:
http://www.motherearthnews.com/Do-It-Yourself/1980-01-01/Wood-Stove-Safety.aspx