Make-Up Air Damper Application Guide

Broan Automatic Make-Up Air Damper Product Guide – 04-17-13 8
Simply put, make-up air is air from outdoors and from other indoor spaces (e.g. transfer air) that
is used to replace air that is exhausted.
2,4
Outdoor air is air that is provided through natural
infiltration across cracks and gaps in the building envelope as well as through intentional
openings, like outdoor air ducts that are opened and closed as needed using the Broan
Automatic Make-Up Air Damper. The primary function of make-up air is to ensure that exhaust
appliances have sufficient air to operate as designed.
3. Broan Automatic Make-Up Air Damper – Product Function
The Broan Automatic Make-Up Air Damper (the “Damper”) provides a pathway for fresh outdoor
air to enter a home from outdoors 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 negative pressure conditions within the home which
may interfere with the proper operation of exhaust and/or 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.
4. Different Models of the Broan Automatic Make-Up Air Damper
The Damper comes in various models – LinkLogic™ (SMD* model) Direct-Wired (MD*T
model), Universal (MD*TU model), and Slave (MD*S model). Each model is available in 6”, 8”
and 10” sizes. The unit size is indicated by the only digit within the model number. For example,
a 6” LinkLogic™ model is model SMD6. The main differences between these models are the
way in which the Damper communicates with the exhaust device and the compatibility of the
Damper with Broan and BEST range hoods.
The LinkLogic™ model (SMD*) establishes communication and control between the exhaust
device and the Damper through a powerline communications protocol. In other words, the
exhaust device(s) and the Damper talk to each other by sending signals across your home’s
normal electrical wiring. The LinkLogic™ model of the Damper works with compatible Broan
exhaust fans (such as the SmartSense® system). Note that Broan range hoods
are not
compatible with the LinkLogic™ model of the Damper.
The Direct-Wired model (MD*T) communicates with the exhaust device through an
independent, hard-wired, low-voltage connection between the exhaust device and the Damper.
The Direct-Wired model of the Damper works with some compatible Broan and BEST range
hoods.
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International Code Council. 2012 International Mechanical Code. Section 501.4. See also the definitions
section of this guide.