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Broan Automatic Make-Up Air Damper Product Guide – 04-17-13
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12. Frequently Asked Questions (FAQs)
1. What does the Broan Automatic Make-Up Air Damper do?
The Broan Automatic Make-Up Air Damper (the “Damper”) provides a pathway for fresh
outdoor air to enter a home when a compatible exhaust device is operating. The Damper
opens when a compatible BEST, NuTone, or Broan range hood or exhaust fan is
operating, thereby creating a known, controlled point for fresh outdoor air to enter the
home while air is being exhausted from the building by the exhaust fan(s) and/or range
hood.
outdoor air to enter a home when a compatible exhaust device is operating. The Damper
opens when a compatible BEST, NuTone, or Broan range hood or exhaust fan is
operating, thereby creating a known, controlled point for fresh outdoor air to enter the
home while air is being exhausted from the building by the exhaust fan(s) and/or range
hood.
By operating in this manner, the Damper provides two key benefits for the home:
It facilitates air exchange between indoors and outdoors, by helping to allow fresh
outdoor air into the home to replace air which is exhausted out of the home.
By allowing fresh outdoor air into the building when a compatible exhaust device is
on, the Damper helps to avoid excessive negative pressure conditions within the
home which may interfere with the proper operation of combustion equipment within
the home.
home which may interfere with the proper operation of combustion equipment within
the home.
Overall, the Damper lets your Broan, NuTone, or BEST exhaust devices do their job
more effectively and without interfering with the proper operation of other home systems.
more effectively and without interfering with the proper operation of other home systems.
2. Does the “Damper” provide combustion air for combustion appliances like a water
heater or a furnace?
No. The Damper helps to replace air which is exhausted by a compatible range hood or
exhaust fan. But it does NOT help to replace air which is drawn from the indoors by a
combustion appliance like a natural gas water heater, and it should not be relied upon to
perform this function. One main reason for this restriction is that the Damper is only open
when the exhaust fan or range hood that it’s connected to is operating. So there is no
assurance that the Damper would be open when other appliances, like a water heater,
are operating. Other means must be provided to ensure adequate combustion air for
these appliances.
exhaust fan. But it does NOT help to replace air which is drawn from the indoors by a
combustion appliance like a natural gas water heater, and it should not be relied upon to
perform this function. One main reason for this restriction is that the Damper is only open
when the exhaust fan or range hood that it’s connected to is operating. So there is no
assurance that the Damper would be open when other appliances, like a water heater,
are operating. Other means must be provided to ensure adequate combustion air for
these appliances.
3. How do I know if I need make-up air for my range hood?
In some cases the local building code may tell you that make-up air is necessary. For
example, some codes specify that range hoods with exhaust flows of 300 cubic feet per
minute (CFM) or higher need a mechanical system to introduce make-up air.
example, some codes specify that range hoods with exhaust flows of 300 cubic feet per
minute (CFM) or higher need a mechanical system to introduce make-up air.
In other cases, make-up air for a range hood is desirable regardless of whether code
requires it. This is especially true for:
requires it. This is especially true for:
‐
larger range hoods (those over 300 cfm), especially in small and/or well-sealed
homes
homes
‐
homes which are well air-sealed - so outdoor air may not be able to easily find its
way into the home through cracks, to replace air which is exhausted
way into the home through cracks, to replace air which is exhausted
‐
homes with natural draft vented combustion appliances (e.g.,. a water heater or
natural draft fireplace), which are more susceptible to improper venting if
depressurization occurs in the home.
natural draft fireplace), which are more susceptible to improper venting if
depressurization occurs in the home.