Guest article written by Robert S. Husted
Many off grid individuals use some sort of wood heat whether it be an old barrel stove, wood-stove or masonry fireplace. Each solid fuel burning appliance has its own set of characteristics on maintenance, use, and safety requirements. Today I will be discussing the common wood stove.
Installing Your Wood Stove:
The first important detail is the installation of the stove itself. Usually you start with a four inch, non-combustible masonry hearth with 24 gauge or thicker sheet metal under the hearth pad. Then you need to adhere to the clearance from combustibles from the wall behind the stove. Most stoves will have a plate that informs you on the distance to maintain. You can apply non-combustible material behind the stove to reduce its clearance to the wall. However, one common mistake is that you can only reduce down by 33% per most standard building codes.
For example, if clearance is 18 inches you could apply noncombustible material to the wall and move stove to within six (6) inches. You should never install the stove any closer than this. The air flow around and behind the stove helps keep the wall from absorbing heat by a process called natural convection. It’s also a good idea to have air flow behind the non-combustible wall with small holes or slits in the bottom and top to allow for natural air flow for cooling and forcing heat to the living space.
The stove pipe connector (single wall pipe) must maintain a clearance of 18 inches to combustibles. Then it transforms to the double wall chimney pipe which has a two (2) inch clearance to combustibles. There should be a fire stop, attic shield and plenty of air flow around pipe until it terminates outside above the roof line. The pipe should have roof support brackets, storm collar, flashing, spark arrester rain cap, and terminate at least three (3) feet higher than the roof peak. When installing the wood-stove, follow all building codes and manufacture guidelines as required.
Using Your Wood Stove:
All stoves, when cold, may want to back-draft smoke back into the living space. There are many factors for this. One, the system needs lots of heat fast to establish a natural draft. As hot air rises from the fire it needs cool combustion air to replace the oxygen consumed in the fire triangle. Sometimes due to high winds or pressure fronts and even the terrain of where the home is located, it can affect the draft. It may be necessary to crack a door or window during start up to break this vacuum with in the home (known as the stack effect). After 20 to 30 minutes there should be little to no smoke coming out from the top of the chimney pipe, only a heat plume.
Second, maintain the fire at an internal flue gas temperature of about 300 F° to 500 F°. This can be done with a stove pipe thermometer. The thermometer should be installed about 12 inches above the top of the stove on the pipe. For double wall pipe you need a thermometer with a probe that is installed into the inside of the pipe. These temperatures are maintained with air controls and dampers installed on the stove itself. If the flue gases are too cold simply add more air and fuel. If temperature is to hot then close off the air flow in small increments until desired temperature is reached.
Wood should be at a moisture content of 17% to 24%. There are testers you can buy for this that range from $20.00 to $30.00. If wood is to wet the chimney will desolve a tar like substance known as creosote. Creosote is also caused by burning “cold”, wet wood, or smolder the fire all night long. I recommend never allowing a fire to smoulder all night long. It is safer to build a new fire every morning. Creosote is very hard to remove and puts you at very high risk of starting a chimney fire. Using properly seasoned wood (split, stacked, uncovered, and dried for at least 8 months) will produce soot. This is a black substance with the consistence of baby powder. The soot is easily removed.
Cleaning Your Stove:
When sweeping or cleaning the chimney system and stove the first thing to do is to put down floor protection in the room where the stove is located. Next, you need to set up a vacuum and remove the baffle system from inside the stove. There are hundreds of different baffle configurations. Please consult the manufacture or a professional chimney-sweep if you cannot figure out how the to remove this system. The baffle must come out to clean the chimney pipe or you can plug the pipe or air tubes with in the stove during the sweeping process. Next is to clean out all the soot in the corners of the stove where the baffle used to be with a paint brush or whisk broom and then vacuum out little lips and ledges.
Make sure the stove door is shut tight and cannot fall open. You do not want to dust out your home. Then safely head up to the roof (you may need ladders, ropes, or other safety gear) remove the chimney cap and clean it off. Then sweep the pipe by inserting a chimney brush into the pipe adding lengths as you go. Move the brush up and down until you reach the bottom. Then remove the brush and allow the dust to vent. Do not breathe dust as it is a carcinogenic, use a respirator mask. Also do not use a chain for cleaning as it may damage the integrity of the pipe. Next inspect the inside of the pipe insuring all joints are flush and the pipe appears smooth and round without any defects. With a bright light you should be able to see in side the stove insuring there are no restrictions. If there is an elbow in the system you may need to look from the top and bottom (inside stove looking up)
Reassemble the chimney cap. Now go back inside and put the vacuum hose inside of stove for dust control and scoop out all soot. Inspect the bricks and baffles and any welds inside the stove. Reassemble the baffle system and vacuum any leftover soot up. Remember, the “hotter” you can burn the stove the “cleaner” the system will stay. Always observe all safety requirements and always consult local codes, state and federal laws on use and installation of wood-stoves. Follow manufacture guidelines on installation and use. The best advice I can give anyone thinking about buying a wood-stove to undersized the unit. This way you will tend to run the unit “hotter” to achieve the desired heat output. For further information you can visit our web site at daveschimneyservicellc.com.
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