A Concise Guide To High Performance Woodburning
The information below re-printed with permission from: http://www.woodheat.org/
The challenge in burning wood efficiently is to burn off the smoke before it leaves the firebox. The rest of the suggestions in this fact sheet will help you get more heat from your wood and reduce creosote deposits and air pollution.
1. Understanding Combustion
As firewood burns, it goes through three phases:
4. Fuel Load Geometry
5. The firing cycle
Don’t expect perfectly steady heat output from your stove. Wood burns best in cycles. A firing cycle is the time between the ignition of a fresh load of wood and its consumption to a coal bed. Each firing cycle should provide between four and eight hours of heating. Plan the cycles to match your household routine. For example, if someone is home all day, two four-hour fires allow better control of house temperature than one eight hour burn. Adjust the amount of wood used in each load to match the amount of heat needed. For overnight burns, adjust the load so that just enough charcoal is left in the morning to kindle the next fire. Fire each load hot for a few minutes to heat the wood thoroughly and form a layer of charcoal on it.
6. The flash fire technique
To avoid overheating the space and smouldering the wood during mild weather, build a small fire and burn it quickly. Rake the coals into a pile at the front of the firebox and load at least three small pieces on and behind the coals. The pieces should be stacked loosely in a crisscross arrangement. Open the air inlet to produce a bright, hot fire. The air supply can be reduced slightly as the fire progresses, but never enough to extinguish the flames.
7. Building an Extended Fire
To achieve a longer-lasting fire, rake the coals towards the front of the firebox and use larger pieces of wood placed compactly against the rear of the firebox. Placing the pieces close together prevents the heat and flame from penetrating the load and saves the buried pieces for later in the burn cycle. Open the air inlet fully and leave it open until the surface of the wood has a thick layer of charcoal and is burning brightly. Then you can reduce the air setting so the flames slow down, but not enough to extinguish them.
8. Removing Ash
remove ash . . . . rake charcoal . . . . place new load
Remove ash from the firebox often so its build up does not interfere with the raking of charcoal and the placement of logs. If your stove is equipped with an ash pan, remember to empty it before it is full to avoid spilling ashes in the housing or on the floor. Once removed, wood ash should be stored in a covered metal pail away from combustible material outside or in the garage. You can sprinkle some of the ash on your flower gardens to reduce soil acidity, or you can put it in a hole dug in the corner of your yard, or you can put it out with other household waste going to a disposal site.
Content Source: http://www.woodheat.org/tips/hiperwoodburning.htm
site development: morgan newcomb