Chimneys are designed to keep the smoke out of your home channeling it up the flue and releasing it outdoors. In other words, your chimney isn’t doing its job if there is any spillage (our fancy word for ‘smoke is getting into the house’). Wood smoke contains HAPs (hazardous air pollutants), VOCs (volatile organic compounds), ash, carbon monoxide, formaldehyde, and nitrogen oxides. These pollutants can cause a number of problems, such as cancer, damaged lung tissue, and respiratory issues.
Chimney failure can be caused by a number of things, and figuring out what the problem is can be a tricky process of elimination. Some of the main culprits are:
Poor ventilation can be caused by blockage in the chimney or in the chimney cap screen. You might have blockage in your chimney from creosote buildup if you haven’t had your chimney cleaned in a while. And though it might not seem like a very cozy spot to you, chimneys make great hideaway homes for birds such as the chimney swift and animals like bats or raccoons that can nest above the damper or on the smoke shelf. Installing a chimney cap with a screen is the best way to ensure this isn’t a potential cause of poor ventilation. Screens can also get clogged—annual inspections can keep you on top of the situation. Weather can also be an issue—if it’s an especially windy day, the wind might be forcing the hot air and smoke from your fireplace back into your home.
Don’t light my fire. Another thing to keep in mind—hot air rises. If it isn’t cold enough outside, wait until it is before you light that fire.
Newer homes are built to be tight as a drum, which is great for those energy bills in the winter and summer months. But fires need air—lots of air—and if there isn’t enough of it inside the home, it will get pulled down through the chimney. Also, keep in mind that there are lots of other appliances that take air from the home, such as exhaust fans, clothes dryers, and even such activities as flushing the toilet or taking a shower. Turning these appliances off or opening a window or door should help determine if negative air pressure is a culprit.
Damper failure can also be operator error—as in, make sure you’ve opened it before starting a fire. If smoke is still getting into the home and you’ve also determined that ventilation and negative air pressure aren’t the issue, have it checked out to make sure it’s actually functioning properly.
Aren’t out of the woods, yet? Something you’ll hear over and over again as you read informational articles on chimneys and fireplaces is to burn dry, seasoned wood. Green woods are damp, and damp woods are…damp. Water takes a lot longer to heat up, meaning the fire can’t ever get hot enough to burn clean.