Is it Better to Run the Fireplace or the Furnace?

The glow from the fireplace is cozy, but across the room it is frosty. Unless you enhance the efficiency of your basic fireplace or install a fireplace insert, the best way to warm your home is to turn on the furnace.

Heat Loss

• According to Energy Guide, the basic built-in fireplace is only 10 percent efficient. Most of the heat goes up the chimney. The Romans put this concept to work to heat their baths, but it takes many chimneys to make this work. Additionally, when the fire dies down, cold air comes down the chimney, yet you cannot close the damper because of the smoke.

Efficiency

• A few basic changes can improve your fireplace efficiency. Glass doors allow you to enjoy the ambiance while keeping out the cold air at the beginning and end of a burn. Heat exchangers, usually in the form of pipes around the firebox, enhance heat circulation in the room. Fans can also help this process. If you are looking for heating options in case of power outages, consider a gas or pellet fireplace insert. These are up to 80 percent efficient when they are vented with outside air.

Safety

• While ventless inserts cost less, they draw oxygen from the room and can emit carbon monoxide. Do not use these units more than three hours at a time, and make sure the room has an air source. The direct-vent units make up for the extra cost in safety and efficiency.