Subject to change without prior notice Revised 07-12
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connect the Bosch Fresh Outside Air damper system
to the HVAC system.
You want to introduce outside air if:
• You want to improve the IAQ (indoor air quality)
of your home by bringing in fresh air while
exhausting air via exhaust or kitchen fans.
Introducing outside air will positively pressurize
your home which will force out stale,
recirculated air when doors and windows are
opened.
• When required by your local code for make-up
air.
• Your home is experiencing negative
pressurization. This could adversely affect
combustion appliances in your home, This would
include gas fi red water heaters, gas stoves and
other combustion equipment.
Caution
The Bosch fresh outside air damper system is not
intended to provide combustion air for appliances.
The recommendations by the manufacturer of the
appliance must be followed. This product is
intended for addressing IAQ only.
InSTAllATIon ConSIDerATIonS
Installing the fresh air duct system requires carefully
selecting the location of installation. The following
points should be considered when determining
where and how the fresh air damper system will be
installed:
1. Installation of the fresh air system as well as all
electrical should be installed by experienced and
licensed professionals. All local codes should be
followed during the installation.
2. The quantity of outside air needed. Follow the
general guidelines here when determining the
size of the damper that is needed for your
application:
• 4" Damper — 70 CFM
• 5" Damper — 100 CFM
• 6" Damper — 150 CFM
Caution
This is a general guideline and Bosch
recommends that a qualifi ed HVAC contractor
or a professional engineer size the duct and
verify that the additional pressure drop will not
adversely affect the air fl ow delivered by the
HVAC fan motor.
3. The routing of the spiral duct must be
considered. Length of duct as well as any fi ttings
will provide excess pressure drop to the HVAC
duct system; this may adversely affect the fan
motor on the HVAC system. The duct design
should provide as little of pressure drop as
possible.
Caution
Bosch recommends that a qualifi ed HVAC
contractor or a professional engineer size the
duct and verify that the additional pressure
drop will not adversely affect the air fl ow
delivered by the HVAC fan motor.
4. The location of where the outside air hooded
intake is mounted on the exterior wall of the
building. The 4", 5" or the 6" round duct will
penetrate the wall at this location also. The
material of the wall must be considered and how
the space around the duct will be patched and
sealed.
Caution
Refer to the local codes on requirements and
restrictions on installation locations. Also verify
if the wall has a fi re rating; as the patch must
provide the equivalent rating of the wall.
5. The fresh air intake should be located no closer
than 10' from exhaust air outlets, other fresh air
intake for combustion appliances, or chimney
stacks. Refer to the local codes as the
requirement may be more stringent. The most
stringent requirement shall be followed.
6. The hooded louver intake should be located
outside, and not in a garage, attic space, or any
other confi ned space.
7. The outside air duct should be connected to the
return air duct as shown in Figure 1. It is not
recommended to have the outside air duct
discharge air directly into the space. This air
4 IAQ Series
Installation Considerations
