Homeowners often ask about the efficiency of fireplace inserts. The answer is that wood stove fireplace insert efficiency is generally good, but some inserts are better than others.

By itself, a fireplace is actually an energy loser because it sucks warm air out of the room, uses it to fuel the fire, and sends it up the chimney as exhaust. Some estimates of heat loss from a traditional open fireplace run as high as 300 cubic feet per minute. So while an open hearth fireplace looks inviting, it’s a net energy loss.

A high efficiency fireplace insert reverses this energy loss and keeps heat in the room where it belongs. These inserts are similar to a woodstove because they are airtight so they don’t need a lot of air from the room to keep the fire burning. The models that extend out onto the hearth are even better because the additional surface area exudes more radiant heat into the room.

Fireplace inserts efficiency is increased if they are EPA approved. To receive EPA approval, the insert must have a catalytic afterburner to get rid of creosote and other gases that pollute the air. Not only does this make for a cleaner, greener world, but it also directs additional heat back down into the living area.

Although proper chimney installation doesn’t affect fireplace insert efficiency, it does make use of the appliance a lot safer, not to mention in conformance with the law. The National Fire Protection Association (NFPA) recommendations regarding inserts are now required in the United States. That means that your fireplace insert must have a direct connection between the unit’s exhaust outlet and the lower section of the chimney flue liner. This is to keep creosote and other debris from building up in the gap between where the outlet ends and the chimney begins.

Regular chimney cleaning is a must for anyone who burns wood. If the appliance and the chimney are only joined by a connector, then you’ll need to move the insert every time you have the chimney cleaned. The cost of this can add up fast. A better solution might be to pay up front to have a full length flue insert installed that makes a positive connection with the appliance’s exhaust opening. With this setup, you won’t need to move a 400-pound stove every time you have your chimney cleaned. For homeowners concerned about fireplace inserts and efficiency, saving money on chimney cleaning is part of the equation.

A fireplace insert guide to efficiency usually recommends purchasing one with blowers installed. This setup adds the benefit of convection to an already efficient appliances. The blowers catch heated air from hollow chambers built into the sides of the unit and blow it back out into the room. In combination with ceiling fans, the effect approaches the comfort of a forced air furnace if you close off any unused rooms in your house. And it definitely costs less than heating with gas or oil.

Aside from the financial benefits, a wood fireplace insert can look every bit as beautiful as an open hearth fire. Most models are available with glass doors so you can see the fire inside. Brass or pewter trim complements any décor. Best of all, it saves money on the heating bill and doesn’t pollute the air, unlike an inefficient fireplace.

A fireplace insert can be a great solution to the inefficiency of a conventional fireplace. The insert is an airtight woodstove that fits into the firebox of your open fireplace and vents up your chimney. Some fireplace inserts extend out onto your hearth, radiating more heat into the room from the top, sides and bottom as well as the front of the unit.

Conventional fireplaces look great, but they’re inefficient because they’re not airtight, so they pull in huge amounts of air from the room, heat it up, and blast the heat straight up the chimney while sending only a small amount back into the room. Like all airtight woodstoves, an insert burns wood in an air-suffocation environment, capturing up to 50 percent more heat than an open fireplace.

The U.S. Environmental Protection Agency (EPA) certifies all new wood stoves, including inserts, so they have to conform to pollution and efficiency standards. Inserts can be made of cast iron or steel. The models with glass doors look great in any room and give the same atmosphere as an open fire, only far more efficiently.

It’s worthwhile to consider buying an insert that comes with a blower system, which traps even more heat from the sides and top of the insert and sending it back into the room. Thermostat systems attached to the blowers can give your insert performance much like a central heating system.

The U.S. National Fire Protection Agency (NFPA) requires an insert to be installed with a connector flue section between the insert and the first section of chimney flue in your home. Canada’s regulations for chimney connection are even more strict. If you really want to play it safe, you’ll re-line your entire chimney when you have your insert installed. It costs more, but it will make the stove draft more efficiently, and you’ll save money in the long run on chimney cleaning costs.

Do you have a factory-built fireplace made of metal? Then you may run into complications if you try to install an insert, or even a woodstove, and vent it up the chimney of the prefab unit. If the prefab fireplace isn’t listed for this type of installation in its factory manual, then you can’t do it—at least, not and collect on your insurance policy if this type of unsafe installation practice results in fire damage to your home. A prefab fireplace usually has a round opening at the top that leads to the chimney, and is made of metal. A masonry fireplace is made of firebrick and vents up to an chimney flue made of terra cotta colored clay. The opening will usually be square.