Seal Fireplace Dampers with Weatherstripping to Conserve Energy

Fireplaces are the largest intentional opening in the home, costing U.S. families over $6,100,000,000 (based on figures as of March 2005) each year in wasted energy costs.

Like a door or window, fireplaces are openings to the outdoors and should be weatherstripped to prevent the loss of heated and/or cooled air. By weatherstripping the fireplace, several benefits are achieved including improved comfort, energy conservation, reduced energy costs, reduced noise, and improved indoor air quality.

Fireplace dampers are not effective at sealing the fireplace. When dampers are closed they do not provide an air tight seal and are quite ineffective at controlling undesired air leakage. Most fireplace dampers are left open. A study showed that 80% of fireplace dampers are inadvertently left in the open position1. Many fireplaces have broken and/or missing dampers.

In a 1990 study designed to measure the leakage area of fireplace with and without the damper closed, Energy Options Northwest had this impressive finding; the effective leakage area (ELA) of the fireplace dampers averaged about 30 square inches when closed. As a frame of reference, the total ELA of typical houses built to moderately tight standards is between 70 and 120 square inches. These results demonstrate that by weatherstripping the fireplace, the total effective leakage area (ELA) of the house can be reduced by 25 – 43%.

Another research study performed in Europe showed similar results. The study showed that an open damper on an unused fireplace in a well-insulated house can raise overall heating and cooling energy consumption by 30%2.

The majority of energy loss in the home is due to air leakage. Air leakage, or infiltration, occurs when outside air enters a house uncontrollably through cracks and openings. Properly air sealing such cracks and openings in your home can significantly reduce heating and cooling costs, improve building durability, and create a healthier indoor environment.