Guide to poorly drafting fireplaces & woodstoves
09/01/2011 16:59, Published by brian, Categories:
—Mountain Man Fireplace and Chimney Inc.—
by Jake T Johnson, NFI/CSIA/FIRE
I’m proud that I was the first chimney sweep on the Front Range to become a CSIA-certified Chimney Sweep. That was almost 10 years ago, but nearly every day I still encounter a chimney that has some type of draft issue.
Many times it’s simply a dirty flue and/or a plugged chimney cap that has restricted the flow of air through the appliance and the chimney. But more often it’s related to “makeup air” coming into the home and the lack of awareness from the homeowner of the causes of poorly drafting fireplaces and woodstoves.
The process begins with thinking of your house as a system of many interacting parts and understanding how all of them affect the airflow into and out of the living space. To be effective, the pieces must all work together. A few key concepts to be mindful of:
a. Proper-user education can overcome most draft issues.b. A hot flue is a happy flue.
c. Externally situated chimneys are colder and therefore more prone to smoking.
d. Most homes don’t have enough fresh outdoor air infiltration (air leaking in) to balance the warm air rising in the home and exhaust fan discharges (air leaking out).
e. The construction and design of the fireplace/stove and chimney are only part of the problem.
• Do open the damper fully
• Do use only seasoned cordwood—the degree of dryness is more important than what tree it came from.
• Do keep ashes to a minimum so air can circulate under the grate.
• Do keep the fire pushed toward the rear of the firebox.
• Do start with some balled up paper and kindling for a quick hot start.
• Do open the combustion air damper, if so supplied.
• Do open a door or window on the windward side before lighting.
• Do prime the flue as necessary with a paper torch.
• Do install glass doors on fireplaces and have them installed by a professional.
• Do keep the fire burning hot.
• Do open heating registers and doors to all rooms.
• Do turn off all competing fans, vents or crossdrafts.
• Do have a CSIA-certified Chimney Sweep clean and evaluate your system annually.
Things to avoid if there are problems
• Don’t use manufactured wax logs alone. They don’t produce enough heat for draft. Mix them with cordwood.
• Don’t use firewood recently purchased unless it has been tested to < 20% moisture content.
• Don’t use any type of green cordwood, lumber, plywood, rotten wood or treated lumber.
• Don’t use any type of chemicals.
• Don’t try to burn on very windy days or during severe storms.
• Don’t use large unsplit logs with the bark on.
• Don’t add larger logs to the fire until a hot bed of coals is established.
• Don’t “bank” the fire for the night. Stir the remaining fuel up in a hot fire until it is consumed.
• Don’t operate exhaust fans including dryer vents, bathroom vents, kitchen exhausts, heat recovery ventilators, central vacuums or the main furnace, if possible, before or while burning.
If your fireplace or woodstove is drafting poorly, it is likely that your home is experiencing a significant level of depressurization, thus making it more likely to allow the spillage of exhaust fumes from water heaters, boilers, kitchen stoves, clothes dryers, other fireplaces and furnaces. Because backdrafting can be a dangerous source of carbon monoxide (CO) poisoning we strongly recommend that every home be equipped with a CO alarm as well as smoke alarms. Accordingly, if the appliance is experiencing smoking, “roll out,” or backdrafting, stop using it until the problem has been properly corrected.
This guide is not intended to be all inclusive since obviously there are many factors associated with each individual home. If you are experiencing these types of problems or would like to learn more about solving your draft problems, we’ll send you a free copy of “How Your Chimney Really Works…. And Why It Sometimes Doesn’t,” a public safety bulletin from the Chimney Safety Institute of America.
Call us today at Mountain Man Fireplace and Chimney Inc., 303-674-5377 or 838-3882, or electronically at office@MtnManChimney.com. Semper Fi!