Build a Better Fire

Before lighting a fire in your wood burning fireplace or wood stove, make sure the thermostat is turned down so air heated by the central furnace will not go up the chimney. The easiest and best fire for either wood stoves or wood burning fireplaces is achieved with a mixture of softwoods for easy igniting with hardwoods for longer burning and good coaling qualities. Biobrick is also a good option. A cardinal rule of fireplace management is to keep a thick bed for glowing coals that drop through. The coals yield a steady heat and aid in igniting fresh fuel as it is added. Keep the fire burning by adding small amounts of firewood at regular intervals. A small, hot fire is much better than a large, roaring blaze because it burns more completely and produces less creosote.

A wood fire or biobrick fire is easy to start and produces a large quantity of heat in a short time as well as adding a cheerful atmosphere to the woodstove or fireplace. An ample air supply to the wood fire is important to ensure complete burning of combustible gases. Wood fires are ideal where heat is required only occasionally, for warming a living area on cool days or for supplying extra heat in extremely cold weather. When considering firewood as a primary heat source, several factors must be carefully weighed to ensure satisfactory results and acceptable deficiencies.

The heat content of any fire depends on firewood density, resin, ash and moisture. A rule of thumb often used for estimating the heat value of firewood is: "One cord of well-seasoned hardwood (weighing approximately two tons) burned in an airtight, draft-controlled wood stove with a 55-65% efficiency is equivalent to approximately 175 gallons of #2 fuel oil or 225 therms of natural gas consumed in normal furnaces having 65-75% efficiencies." Generally, hardwoods which provide long-burning fires contain the greatest total heating value per unit of volume. Softwoods which give a fast burning, cracking blaze are less dense and contain less total heating value per unit of volume. All firewoods dried to the same moisture content contain approximately the same heat value per pound-from 8,000 to 9,500 BTU for fully dried wood and 5,500 to 8,500 BTU for air-seasoned wood.

Precautions

Coal should never be burned in a wood stove or heater designed for wood. Artificial or manufactured logs (excluding biobrick), which are composites of sawdust, chips, colorful chemicals, starch binders and wax should be burned only in open brick fireplaces. The wax burns at too hot of a temperature for metal wood stoves and chimneys. When using manufactured logs in fireplaces, never crumble the burning log with tongs or a poker. Avoid using firewood salvaged from poles, posts, and lumber that has been treated with wood preservatives such as creosote or pentachlorophenol. These chemical compounds may vaporize upon combustion and cause respiratory problems for those breathing the fumes. Wet, green wood, or highly resinous firewood should not be burned because of the large amounts of wood tars, creosote and wood extractives given off which can coat chimney flues and cause serious chimney fires if ignited.