Fireplace Dampers 101

Fireplace dampers are key chimney system components that work for you year-round, not just when you’re using the fireplace. Ye Olde Brit Chimney Sweep of San Bernardino, CA, would like to share some “nuts and bolts” about this useful component.

Damper design

There are various styles of dampers, but they all work essentially the same way: they open and close. A throat damper is located just above the fireplace. A top-mount damper is located at the top of the chimney over the flue opening. When closed, a top-mount damper guards the flue against rain, debris, and small animals.

Use when running the fireplace

Fire requires three elements: fuel, heat, and air. The fuel is your firewood. The heat is the flame you use to start the fire. The air is what gives the fire life, and that’s where the damper comes in.

Chimney systems run a draft. When correctly built and sized, the chimney will draw air from the room and into the firebox, where the fuel and heat are ready to create a fire. Air passing over and through the burning logs allows the fire to burn robustly and completely. An open damper allows for this draft.

A wide-open damper will give you the air needed to get a fire started. As the fire progresses, slight adjustments to the damper will affect how robustly the fire burns and for how long.

Using the damper when the fireplace isn’t operating

When you’re not using your fireplace, the damper should be closed completely. This prevents conditioned air in the home from escaping while keeping unconditioned outside air from getting in.

There are three other reasons to have the damper shut at all times except when you’re using the fireplace:

Odor prevention

Most chimneys emit odors. A chimney that’s cleaned regularly will have less odor, but no chimney is odorless. A closed damper helps to keep these smells out of your home.

Animal invasion

If you operate your chimney without a chimney cap, small animals (squirrels, birds, rodents, etc.) can get into the flue and wind up in your house.

Downdrafts

Wind coming down the chimney can blow soot and ash from the fireplace into your room. A closed damper prevents the resulting mess.

A note on chimney caps: Chimney caps cover the flue opening at the top of the chimney and keep rain, animals, and tree debris out of the flue while reducing the effect of downdrafts. If you don’t have or want a top-mount damper, you should have a chimney cap installed.

Fireplace damper inspections

Regular chimney inspections should include an assessment of the damper. Your technician will check to make sure it’s free of rust, properly fitted, and able to open and close correctly.

If rusted, the damper can be cleaned. In severe cases, it can be replaced. If there’s rust on the damper, that means there’s water in the flue, so that’s something else the inspector will check.

Help for all of your chimney needs

Ye Olde Brit provides our Southern California customers with complete chimney inspections, sweeping service, and chimney repairs. We’ll make sure your damper and all other parts of your chimney are working right.

Speak with a chimney expert by calling (909) 880-2120. You can also reach out with our simple contact form.