Fireplaces and Wood-Burning Stoves can be great additions for the comfort of your homes, but there are several things to be taken into consideration. Fireplaces are usually an auxiliary source of heat, designed rather to create a cozy, relaxed atmosphere. Since they are very inefficient they cannot be economically justified, and a fireplace requires a large volume of air for combustion. This air is normally drawn from the heated air in the house.
The combustion air flows up the chimney, so all the fuel that had been used in heating the air is wasted. A fireplace should have dampered air vents that provide combustion air from the outdoors in order to minimize this problem. Newer fireplaces have provisions for outside air, however most older ones do not have this feature so they waste more heat than they generate.
In terms of the total heating value of the wood being burned, a wood burning fireplace does not generate much heat at all. Just 10 to 15 of the available Btus find their way into the room, the rest of the warm air disappears up the chimney.
Moreover, even when not in use a fireplace is still a source of heat loss. If the flue is not blocked, heat in the house will be drawn up the chimney, but this condition can generally be minimized by closing the damper.
Fireplaces and Wood-Burning Stoves Inspection
Check the fireplace to see if there is a damper and if there is, whether it properly seals the flue opening. In many older homes, existing fireplaces do not have dampers. If a movable damper costs to much to install, another solution would be to block the flue with a piece of sheet metal supported by guides on the sidewalls. This can be inserted and removed whenever necessary.
Some fireplaces are designed with built-in convection ducts around the firebox, functioning as a heat exchanger. As cool air enters the bottom of the ducts, it circulates around the firebox and gets heated. This type of fireplace is more efficient for heating than the open-faced masonry fireplace.
On the other hand, a wood burning stove is a far more efficient way to heat the house. A high-quality stove will allow only the air needed for combustion into the unit, so heated room air so not lost up the chimney as with the fireplace. In addition, if you control the airflow through the stove, a log will produce more heat by burning a longer period of time. And since the stove is physically located in the room that it is supposed to heat, the unit’s entire surface will heat up and warm the room by convection and radiation.
Whether a wood-burning stove is actually cost-effective for heating depends on the cost of wood being burned. In areas where wood is inexpensive, a stove is an economically justifiable method for providing auxiliary heat. Also, different woods have different burning characteristics. Wood from conifer trees, for instance, burns more quickly and gives less heat than wood from deciduous trees such as maple, oak and beech.