Best MD10TUX User Guide

Page of 20
Broan Automatic Make-Up Air Damper Product Guide – 04-17-13 
 
19 
 
In homes with any one of these factors make-up air is advised. And in homes with more 
than one of these conditions, make-up air for the range hood is strongly advised. 
 
4.  What are the benefits of providing make-up air to replace air which is exhausted 
out of the home by a range hood or bathroom exhaust fans? 
Exhaust fans in a home are designed to pull out pollutants like cooking odors or moisture 
from a shower at the source, so they don’t linger in the home. Because these fans pull 
air out of the house, this air needs to be replaced with “fresh” air from outdoors. Normally 
this make-up air enters the home through cracks and holes in the “shell” of the building. 
But modern homes are air-sealed much more thoroughly so there are not as many 
cracks and openings. Plus some exhaust fans like range hoods may be designed to 
exhaust more air than can be replaced through normal cracks in the building shell. 
By providing an intentionally designed opening for fresh outdoor air to replace air which 
is exhausted by the range hood or bath exhaust fans, several important benefits result: 
‐ 
A larger amount of the make-up air entering the home comes in at a known point, 
where it can also be filtered 
‐ 
The severity of negative pressure conditions, which could arise if air is exhausted 
from a home without being replaced by fresh outdoor air, are reduced 
‐ 
Pollutants are more effectively exhausted from the home while fresh outdoor air 
is drawn into the home, improving ventilation 
 
5.  Does ASHRAE 62.2 – “Ventilation and Acceptable Indoor Air Quality in Low-Rise 
Residential Buildings” – require the use of a make-up air damper? 
ASHRAE 62.2 does not specifically require make-up air dampers. In a few limited 
circumstances, this standard does require that net exhaust flows from a house be either 
limited or that make-up air be provided. For example, Section 6.4 of the standard limits 
the net exhaust flow from a home’s two largest exhaust appliances, or requires make-up 
air to be provided, if the home has natural draft vented or solid-fuel burning appliances 
located within the pressure boundary of the house. This standard is available at 
www.ashrae.org
.  
 
6.  Can I use the Broan Automatic Make-Up Air Damper with other equipment in my 
home?   
The Broan Automatic Make-Up Air Damper is approved for use with compatible Broan, 
BEST, or NuTone range hoods or exhaust fans. Unless specifically noted, Broan does 
not warrant proper operation of the Damper if used in conjunction with other brands of 
exhaust devices.  None of the Damper models should ever be used to provide 
combustion air for combustion appliances.  More information on various models of the 
Damper and compatible exhaust devices can be found in the Make-Up Air Specifier on-
line tool and in the individual Broan Automatic Make-Up Air Damper specification sheets.