• Manufactured by Chimney Balloon
• 608-467-0229; www.chimneyballoon.us 
• Cost: prices start at about $43

As air is heated, it expands and becomes less dense, causing it to rise. This is the principle that causes smoke to travel up the chimney from your fireplace. Unfortunately, the same principle is also hard at work when you don’t have a fire burning in the fireplace. As warm interior air rushes up a chimney, cold air rushes in to replace it from under the front door, around the window sashes, and up from the cold basement. The colder it is outside, the faster the exchange of air, and the harder the heating system has to work to keep up. Flue dampers and glass fireplace doors help to slow the heat from escaping up the chimney, but they aren’t designed to be airtight.

A better option might be the Chimney Balloon. After this 3-ply-poly draft stopper is partially inflated, it is inserted into the top of the firebox. Once in position, the balloon is inflated fully, by mouth or with a pump, using a 1/2-in.-dia. poly tube. A red tag sits in the firebox as a reminder to remove the Chimney Balloon before starting a fire. If you forget, the balloon quickly deflates.

Chimney Balloons are reusable, available in more than 70 sizes, and work in any chimney as long as you can get an accurate interior measurement.

Photo and drawing by: Krysta S. Doerfler