Fantech ATMO Series, Installation And Operation Manual

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.

1

  Using 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.

2

  Pull 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.

4

  Using a caulking gun, seal 

around both hoods to prevent 
any leaks.

STEPS FOR HOOD INSTALLATION:

36" (1m)

INTAKE

OUTSIDE CORNER

INSIDE CORNER

EXHAUST

18" (460mm) 

18" (460mm) 

3' (900mm)

min.

36” (1m)

REQUIRES A WEATHERHOOD 

WITH A BACKDRAFT 

DAMPER ON THE EXHAUST 

SIDE.