9
8
EXTERIOR DUCTING INSTALLATION
WEATHERHOOD LOCATION
• Decide where your intake and exhaust hoods will be located.
Locating the Intake Weatherhood
• Should be located upstream (if there are prevailing winds) from the
exhaust outlet.
• At a minimum distance to 900 mm (3') away from dryer vents and furnace
exhaust (medium or high efficiency furnaces), driveways, oil fill pipes, gas
meters, or garbage containers.
• At a minimum height of 460mm (18’’) above the ground, or above the level
of expected snow accumulation.
• Ideally, keep weatherhoods 1m (3') from corners.
• Do not locate in the garage, attic, crawl space, or underneath deck.
Locating the Exhaust Weatherhood
• At least 460mm (18") above ground or above the depth of expected snow accumulation
• Ideally, keep weatherhoods 1m (3') from corners.
• Not near a gas meter, electric meter or a walkway where fog or ice could create a hazard
• Do not locate in a garage, workshop or other unheated space
INSTALLING THE DUCTING TO THE WEATHERHOODS
A well designed and installed ducting system will allow the FAA to operate at its
maximum efficiency. The inner liner of the flexible insulated duct must be secured to the
sleeve of the weatherhood (as close to the outside as possible) and to the appropriate duct
connection on the FAA. The insulation should remain full and not crushed. The outer liner,
which acts as a vapor barrier, must be completely sealed to the outer wall and the FAA
using tape and/or caulking. A good bead of high quality caulking (preferably acoustical
sealant) will seal the inner flexible duct to both the FAA duct connection and the
weatherhood prior to securing them.
To minimize airflow restriction, the flexible insulated duct that connects the two outside
weatherhoods to the FAA should be stretched tightly and be as short as possible.
Twisting or folding the duct will severely restrict airflow.
See “Installation Diagram Examples” for installation examples.
1Using the duct connection of
the outside hood, outline the
intake & exhaust holes to be
cut. The holes should be slightly
larger than the duct connection
to allow for the thickness of the
insulated flexible duct. Cut a
hole for both the intake and
exhaust hoods.
3 Push the hood into the opening
and then attach the hood to the
outside wall with mounting
screws.
Repeat the installation
procedure for both the supply
and exhaust hoods.
2Pull the insulated flexible duct
through the opening until it is
well extended and straight.
Slide the duct’s inner vinyl sleeve
over the hood duct connection
and secure. Pull the insulation
over the duct and pull the vapor
barrier over the sleeve. Secure
with appropriate tape or
sealant.
4Using a caulking gun, seal
around both hoods to prevent
any leaks.
STEPS FOR HOOD INSTALLATION:
36" (1m)
min.
INTAKE
OUTSIDE CORNER INSIDE CORNER
EXHAUST
18" (460mm) min. 18" (460mm) min.
6' (2m)
min.
36” (1m)
min.
Interior ducting installation
• To maximize airflow through the ductwork system, all ducts should be kept short and have as few bends or elbows as possible.
• 45º elbows are preferable to 90º.
• Use “Y“ ducts instead of “T” ducts whenever possible.
• All duct joints must be fastened with screws or duct sealant and wrapped with aluminum foil duct tape to prevent leakage.
• Galvanized ducting from the FAA to the living areas in the house is recommended whenever possible, although flexible ducting
can be used in moderation when necessary.
• To avoid possible noise transfer through the ductwork system, a short length (approximately 300 mm, 12’’) of nonmetallic flexible
insulated duct should be connected between the FAA and the supply/exhaust ductwork system.
• The main supply and return line to/from the FAA must have the same diameter as the duct connection or larger.
• Branch lines to the individual rooms may be as small as 100 mm (4’’).
Installing ducting to FAA
For flexible duct installation, slide flexible ducting onto duct connection. Then install a
cable tie over flexible duct to prevent leakage between the ducting and the duct
connection.
In the case of solid ducting, slide duct over duct connection, screw in place and seal.
Supply air grilles location
In homes without a forced air furnace, fresh air should be supplied to all habitable rooms, including bedrooms and living areas. It should be supplied
from high wall or ceiling locations. Grilles that diffuse the air comfortably are recommended. In homes with a forced air furnace, you may want to connect
the FAA to the furnace ductwork (see information below).
Exhaust air grilles location
The stale air exhaust system is used to draw air from the points in the house where the worst air quality problems occur. It is recommended that return
air ducts be installed in the bathroom, kitchen, and laundry room. Additional return air ducts from strategic locations may be installed. The furnace
return duct may also be used to exhaust from. In this method, the exhaust air is not ducted back from bathrooms, kitchens, etc to the FAA with
“dedicated lines”.
As per building codes and installation requirements for combustion appliances:
Air return ducts, or openings for air return, should not be placed in enclosed spaces containing combustion
appliances that are subject to spillage.
*Collars may differ depending on the unit.
