What is the Difference Between a Backdraft Damper and a Barometric Damper?

Not every building is created the same way, and thus, their HVAC requirements can also vary. In the past, large high-rise buildings would have a double set of doors, which created a “chimney effect” when they were opened simultaneously under the correct conditions (cold air, heated building). This resulted in lost heat and embarrassment for those whose clothes and hair are blown awry in the resulting gust, which ultimately led to the widespread advent of revolving doors to combat the problem.

Backdraft Dampers Help Keep Your Indoor Environment Safe and Healthy

Duct systems within your home display similar behavior, where exhaust needs to escape to the exterior of the home and not accumulate within your home. However, when the duct system is not in use, outside air should not be permitted to blow back into the house, so how is this achieved? Through the use of a backdraft damper.

Not only does a backdraft damper prevent outside air from blowing back into the building, but it also helps keep your home well-ventilated, as well. If you’ve ever walked into an older home and picked up a strong odor of moisture and mildew, malfunctioning or a lack of backdraft dampers could be to blame.

Typically, backdraft dampers are placed somewhere within the duct system and are easy to install without having to call a professional. 

Have a Chimney? Barometric Dampers to the Rescue

Barometric dampers, also known as draft regulators, are what keep your living room from quickly filling up with smoke when the fireplace is in use. Also, backdrafts and pests can also become a problem without a barometric damper as part of your installation.

In a worst case scenario, built-up pressure within the flue and the unintended spread of a house fire can all be prevented with a barometric damper. For the latter, the damper will open, effectively containing the fire, and for the former, smoke will not find its way back into your home.

So What’s the Difference Between Barometric Dampers and Backdraft Dampers?

In essence, the only difference between barometric and backdraft dampers is where within your HVAC system they are used. They both do their part to:

• Keep outside air from entering into the home.
• Help keep your indoor environment healthy and well-ventilated.
• Provides effective exhaust for your chimney and/or duct system.

Backdraft dampers are typically used for:

• Heat exchangers
• Solar heating systems
• Exhaust systems
• And other intake/exhaust applications that don’t require a powered damper

Aside from chimneys, barometric dampers are typically used for:

• Dryer ventilation
• Oil furnaces
• Boilers
• Water heaters

How FAMCO Can Help

FAMCO has a wide variety of barometric dampers and backdraft dampers in all shapes/sizes to suit every need. We also provide installation/introduction videos for many of our products. We also have a Resources page that you can check out should you need help with calculating how much roof ventilation you’ll need or determining the specific pitch on your roof.

If you have any questions, feel free to contact us. We’d be happy to help.