In its original form, this article was posted on the Sense.com website.
Do you want chestnuts roasting on an open fire but not Jack Frost nipping at your nose? You can curl up with a book or a cup of hot chocolate with your significant others before a fire this winter while making your fireplace safer and more efficient.
Fireplace Regulations
Concerns about the health impacts of smoke and particulate matter from chimneys have led to restrictions on open fires. Particles less than 10 micrometers in diameter from burned wood get lodged in our lungs, increasing the risk of asthma and other respiratory diseases, especially for children and older adults. This is especially true of fire-prone areas with dry and hot climates like ours. Open-hearth wood-burning fireplaces in California are not allowed in homes built after 2016. In the Bay Area, any wood burning is forbidden on what we call “Spare the Air Days.”
A government-sponsored website, AirNow, will show you the air quality in your area. Several apps, including AirNow, are available for iPhones and Android devices that track the weather, including air quality, on your phone.
Still, there are ways to enjoy a fire on clear days without putting the health of your neighbors or family at risk. And you don’t have to lose all that heat generated from the fire as well as the costly heat from your furnace, up the chimney with the smoke.
Ready for a Fireplace Upgrade?
The design of your fireplace can have a significant impact on its safety and efficiency. (The EPA has an excellent overview of fireplace types.) Here are some options for improving the performance of fireplaces, from the most basic to the most sophisticated.
This article is focused on fireplaces and not home heating devices such as pellet stoves, or what are sometimes called “Swedish Fireplaces.” Swedish, or masonry, fireplaces are built with material that holds heat and radiates it to its surroundings over time. The exhaust gasses pass through a maze of channels before being exhausted. The heat is absorbed into the masonry, making them very efficient heaters, but they require a significant construction project.
Chimney Balloons Can Stop Cold Air
Typical old-fashioned fireplaces leak a lot of energy and create drafts all year, especially in the winter when there is a significant temperature difference between indoors and outdoors. One big reason is that most dampers are metal and rarely air-tight, even when closed.
A chimney balloon is an inflatable device that fits just below the damper in your fireplace and blocks airflow. Don’t use a chimney balloon when you have a fire burning! But after the smoking embers turn to ashes, it’s a great way to save energy and be more comfortable.
Research in the UK—where they know chimneys—shows that chimney balloons can decrease airflow by more than 80%, which means they save energy by eliminating cold downdrafts or warm air escaping the chimney. Chimney balloons are a little kludgy to install but are worth the effort. If your fireplace has tight glass doors and an outside air intake, a balloon wouldn't be necessary.
Tight-fitting Glass Doors
An old-style open fireplace will draw air from inside the home for combustion. The "chimney effect" (hot air rising up the chimney) creates a vacuum which sucks your home's inside air up the chimney to the great outdoors. This is why California's building energy code has long required that fireplace retrofits be equipped with both tight-fitting glass doors and an outside air intake into the firebox.
Consider Gas and Electric Fireplaces
Electric fireplaces can be relatively airtight and need no chimney while generating a lot of radiant heat. Their biggest downside is aesthetics since it’s hard to make an electric fire look like a real fire.
Gas fireplaces do need a chimney or some exhaust pipe. To create a cheery fire, you can use gas to start a wood fire and then turn the gas off. Gas fireplaces give off heat, but burning gas produces CO2, carbon monoxide, and other nasty gasses like nitric oxide. Propane flames (versus natural gas) do emit significantly less harmful fumes. Be sure that gas fireplaces are well-vented to the outside so that gasses don’t escape into your home.
Burn More Cleanly with Fireplace Retrofits and Inserts
If you love the look and spontaneity of a wood fire, fireplace retrofits to your existing wood-burning fireplaces can make them more efficient and less polluting. Retrofits typically fit inside your existing fireplace and use materials that increase the fireplace’s temperature so the wood burns more efficiently and cleanly. Some devices claim to reduce emissions by 70% or more.
Fireplace inserts are more efficient and less polluting than fireplace retrofits. Inserts fit into a traditional masonry or metal firebox and operate like a free-standing wood stove that can be used efficiently and safely. They need to be sized correctly to fit the existing space. There are wood, gas, and electric fireplace inserts.
Inserts can control the air intake and, therefore, the burn rate of the wood, making it more efficient. Some fireplace inserts come with fans or blowers that help take the heat around the firebox and distribute it to the room.
Step up to EPA Standards
The EPA does not certify or regulate fireplaces and fireplace retrofits, but it “qualifies” them through a Voluntary Fireplace Program. EPA recommends that you check your state or local government and clean air organizations to determine what is legal in your area before embarking on a retrofit project.
The EPA does certify wood-burning fireplace inserts through its EPA Certified Wood Heater Database. Certified wood-burning appliances emit particulate matter below a certain level, about 4 to 8 grams per hour, depending on the type of device. If you're burning wood, rather than a cleaner alternative, EPA-rated fireplaces (and wood stoves) are the way to go.
The EPA has many good tips for burning wood, including storing wood and disposing of the ashes. Check out its Burn Wise online resource. Everything you want to know about burning wood, or roasting chestnuts, cleanly and efficiently. With a little effort, you can enjoy a relaxing time by the fireplace this winter while minimizing wasted energy and keeping your family, neighbors, and the air we breathe healthy.
Photo by Sergei Solo on Unsplash
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