Ventamatic CX36BD2SPD - Manual (Page 3)

-3-
HOW DO THEY WORK?
Whole House Fans are designed to pull in fresh,
cool air from the outside through open windows in
the living space. Hot air is pulled up through the
fan, into the attic, and then exhausted through
static vents in the undereaves, soffits, roof or
gables.
The necessary exhaust ventilation is measured
in square feet of Net Free Area (NFA).
Failure to provide sufficient NFA will reduce the
fan's efficiency, resulting in noisy operation and
the ultimate failure of the motor.
FAN SIZE
SQUARE
FOOTAGE OF
LIVING AREA, OR
ATTIC SIZE IF
MULTI-STORY
MINIMUM NFA
(NET FREE AREA)
EXHAUST
REQUIRED
24-in
up to 1800 sq ft
if 1 story, or attic
size if multistory
8 to 10 sq ft
(1152 to 1440 sq
in)
30-in
2000 to 3000 sq ft
if 1 story, or attic
size if multistory
10 to 12 sq ft
(1440 to 1728 sq
in)
36-in
over 3200 sq ft
if 1 story, or attic
size if multistory
12 to 14 sq ft (1728
to 2016 sq in)
•
Drill
•
1/4” and 1/8” drill bits
•
Straight edge ruler (yardstick, 4 ft level)
•
Pencil or marker
•
Circular saw
•
Ring shank drywall nails (1 1/2”)
•
#12D nails
•
Adjustable wrench
•
Flat head screwdriver
•
Phillips head screwdriver
•
Safety goggles
•
Speed square
•
Saber saw, reciprocating saw
Tools and Materials Needed:
SELECT THE INSTALLATION SITE
Every house is different and there is no set rule for
the choice of the best site. Check the attic
immediately above potential sites for ducts, piping
or wiring that would obstruct the installation area.
The location should also be an area which is open
during operation. Generally they are installed in
hallways or laundry areas. However they should
not be too close to the kitchen or bathrooms so as
not to exhaust unwanted odors, grease, or humidity
into your attic.
The installation site must provide approximately 48-
in of unobstructed clearance between the fan
blades and the roof, in order for the exhausted air
to disperse correctly and not drop back down on the
shutters.
Joist-in Installation Joist-out Installation
If you choose this method, you will leave the
ceiling joists intact. You will also need to have
another attic access, as the fan will not fit through
the shutter opening with the joist(s) in place. This is the preferred method, as the best location
will not necessarily coincide with the position of
the joists. For this method, you will remove one or
more ceiling joists.
READ THE FOLLOWING BEFORE PROCEEDING
The fan and shutter are designed for horizontal installation only - the louvers will not function in the vertical
position. Decide whether you will use a Joist-In or Joist-Out installation.