From the late 1700’s fireplaces heated homes inefficiently. Some of them, such as most masonry (brick) fireplaces, are still this way. The flue of a masonry fireplace allows warm indoor air to escape up the chimney with poor fitting, warped, unclosed or missing dampers. Or in negative pressure situations such as basements and lower levels these fireplaces become a continuous source of cold air infiltration. When they burn, conventional masonry fireplaces throw nearly 90 percent of the heat they generate up the flue. Since they use nearly 300 to 500 cubic feet of air to support combustion, they actually remove more heat than they supply. They create about 400 grams of particulate per hour.
So why is it that among the 1,700 homeowners across the country recently surveyed by the Hearth, Patio & Barbecue Association, nearly two-thirds considered their fireplaces or stoves a major selling point to home buyers? According to the survey, consumers believe that fireplaces and stoves increase the value of their home, estimating the increase of a home's value at about $2,900 (for gas fireplaces and freestanding stoves) up to $4,400 (for a regular fireplace). These consumer estimates of value are low, according to a National Association of Realtors study which found fireplaces have a positive effect on the selling price of a home, adding about 12 percent to the value.
So is emotion trumping common economic sense? Is wanting a fireplace making us ignore long term costs and energy waste? It doesn’t have to as there are solutions for these inefficiencies. They are called inserts. Wood burning inserts can cut the air changes to 30 to 50 cubic feet of air while returning nearly 70 percent of the heat and reducing emissions to 4 grams per hour. While a single charge of wood (4 to 6 split logs) in a fireplace last about 45 minutes, that same load will burn at least 2 ½ hours. You can also control the heat out put from the insert by slowing the air intake and the consequent heat production and make your fire last up to 8 hours.
A wood burning fireplace insert is essentially a stove without legs. It has a convective jacket that directs its radiant energy back into the room, sometimes with a fan assist. We have inserts constructed of steel, cast iron, steel with cast fronts, and soapstone lined cast units. The construction doesn’t affect the efficiency which is around 70%, but does change the rate of heat transfer. These inserts range in their heating capability from 800 to 2000 square feet depending on the cubic capacity of the firebox.
Before you come visit us, take the time to measure your fireplace (use our handy, printable guide found elsewhere on this page), perhaps take a digital photo, and think about how you intend to use this supplemental heater.
All the gas burning inserts we sell are direct vented except the Valor Adorn. This means they won’t use any house air. They have similar efficiency ratings and your comparison of one unit to another should always be on the AFUE (Annual fuel usage estimate) rating. Sizing an insert is a two step process. First, will it fit in your fireplace? Second, can the room where it’s being installed accommodate that extra heat? We usually figure that you can put up with approximately 15 to 25 BTU’s per square foot with 8 foot ceilings. Each insert has a variable range, some greater than others.
Decide what’s important to you: high efficiency, aesthetics, log look, quality of construction, etc. Remember that each insert is made up of three elements: the firebox, the face, and the surround. The firebox is what it is. There may be as many as 16 different faces and the surrounds can be factory made or customized to your fireplace.
You might also read what Mark Twain had to say about our fireplaces... Click here