Fireplace Inserts
Making improvements in the fireplace you have
Wood-burning insert.
Firebox inserts
Installing a new "stove" in your existing wood-burning masonry fireplace will greatly reduce pollution from burning as well as increase heating efficiency. Firebox inserts can be fueled by wood, pellets, gas, or electricity.
Usually made from plate steel or cast iron, inserts may fit flush with the firebox opening or project a bit onto the outer hearth. The latter configuration provides some additional radiant heat from top, bottom, and sides. Like freestanding stoves, inserts usually have glass doors for fire-watching as well as heating efficiency; nearly all have an outside air system that keeps the glass clean. Many offer porcelain enamel finishes in a range of colors.
A trim kit allows you to fit the insert neatly into the firebox space. Inserts usually have blowers for increased heat circulation. Other practical elements include removable ash pans and levelers for uneven hearths.
A pellet insert can be an excellent choice for a fireplace upgrade. Easy to operate, clean, and heat-efficient, pellet-burners offer an even output of heat, especially with a blower.
Provided there's a gas source to hook it up to, a gas insert can be installed in an existing masonry fireplace. In most ways, these units look the same and come with the same options as wood-burning inserts, though they may also have remote controls and wall switches or thermostats. Most gas inserts require venting through a chimney liner, though some that are less heat-efficient don't require the liner -- check the manufacturer's requirements.
Electric inserts are easiest of all to install. All you need is a convenient place to plug them in.
Heat exchangers and grates
A fan-driven heat exchanger or blower combines an airtight door with heat-exchanging tubes that wrap around the fire. A variable-speed blower draws in room air and returns the fire-heated air to the room. The unit fits into the existing firebox and can be adjusted with a trim kit to fit the opening snugly. Glass doors and a built-in fire screen allow a view of the fire. These units usually don't require a chimney liner, but check local building codes.
Grate heaters, or heat grates, work on the same general principle as heat exchangers: they draw in room air, circulate it through steel tubing, and send the warmed air back into the room. But instead of being sold as a complete package, they are offered as separate components (with or without a variable-speed fan) that can be combined with glass doors that you purchase separately.
Grate heaters are available for use with either wood or gas. At least one manufacturer offers a grate with a cast-iron heat reflector shield that radiates still more heat into the room.
