Early-morning temperatures in these Santa Lucia Mountains have been well below freezing lately. The white ground sparkles, the frozen leaves crunch underfoot, and the water in the birdbaths looks like mini ice-skating rinks. In the light beam from my flashlight, warm exhalations swirl like a Van Gogh sky. It’s a winter wonderland out there, and those of us who depend on firewood for heat are blazing through our stacks to stay comfortable.
Ironic isn’t it? Most of the year, fire evokes fear and anxiety up here. Come subfreezing temperatures, suddenly fire equals comfort. That’s not to say there isn’t cause for concern when fire’s contained in a vented metal box. There is. If you too burn firewood to heat your home, for the sake of safety and for peace of mind, operate and maintain your appliance according to the manufacturer’s instructions, sweep the stovepipe annually, and change the batteries in your smoke alarms and carbon monoxide detectors while you’re at it.
When heating your home with firewood start with an EPA-certified insert in your fireplace or a compliant freestanding woodstove that operates cleanly and efficiently. Efficient units generate more BTUs or British Thermal Units, a standard used to measure heat.
A BTU is the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit. Heavier wood contains more potential BTUs per volume than lighter weight wood. That means you’ll have to burn considerably more pine than you would a denser wood like oak to get the same amount of heat.
Seasoned wood, fewer pollutants
Whatever type of firewood you choose, make sure it’s seasoned and dry. Seasoned firewood is wood that has been cut and air-dried for at least a year (longer for certain species and in damp climates) and preferably stored off of the ground to discourage mold and insect infestation. Firewood that is well seasoned has 20 percent moisture content or less by weight. It ignites easily, burns bright and barely smokes. You get the most heat and the fewest pollutants with seasoned wood.
If you try to burn unseasoned (green) and/or wet wood, sap and water will hiss out the ends of logs that will smolder. A smoldering log produces minimal heat and a lot of soot, tarry smoke and creosote — the flammable material that adheres to the chimney or stovepipe’s inside walls.
Many homes have burned to the ground from fire in the flue.
So prevent smoky fires that also pollute the air, threaten health, and waste fuel. Never burn wet, green, painted, stained or treated wood, colored newsprint, magazines, plastic or garbage, which all produce high amounts of toxic smoke and fumes.
Wood with some of the highest BTU ratings are eucalyptus, oak, almond, madrone, maple and olive, as well as fruitwoods such as apple. All will warm your home and your bones very well on a cold winter night.
Sycamore, avocado and resinous conifers like pine have lower BTU ratings but work well to kindle the wood burning process.
Michele Oksen’s column is special to The Cambrian Email her at overtheridge@