Dryer Booster Installation and Operation Manual

3
Dimensional Data
A
B
C
D
E
F
A B C D E F
DBF 110 3
31
/
32
4
31
/
32
12
3
/
4
11
1
/
4
9
1
/
2
10
5
/
8
A
B
C
E
D
A B C D E
DBF4XL 3
7
/
8
9
7
/
8
8
1
/
4
9
1
/
4
8
5
/
8
Dimensions are in inches.
Illustration 1
Dryer Exhaust Fan
Alternative Location
Secondary Lint Trap
FC Mounting
Clamps (optional)
Installation Guidelines
Fan and Switch Mounting
The DBF110 or DBF4XL is to be mounted a minimum of 5 linear (not equivalent) feet from the
dryer outlet. A secondary lint trap (DBLT 4W) is recommended if the fan is installed between 5
and 15 linear (not equivalent) feet from the dryer outlet in applications, where excessive dryer lint
generation is likely or to increase the time interval between routine maintenance of the Dryer
Exhaust Fan (See illustration to left). An NB mounting bracket attached to a rafter or joist should
be used to stabilize the fan. Although not recommended, a vertical rigid duct may support the fan
if the duct is securely stabilized. (Consult local codes prior to supporting the fan in the duct
alone.) Duct work should be attached to the inlet and outlet of the fan by means of FC vibration
isolation clamps (not included) or duct tape. The duct connection should be properly sealed to
prevent leakage and loss of fan performance. Flex duct connections between the dryer duct
connection and exhaust duct should be stretched as smooth as possible.
Calculating Duct Run
To calculate the length of your planned duct run, measure from the dryer to external venting point
in roof or wall. For each bend or elbow add 5-7 feet to your total duct run calculations. The
DBF110 and DBF4XL can be used on runs up to 120 feet.
Pressure Sensor Switch Operation
Fantech's DBF110 and DBF4XL are equipped with a positive pressure sensing switch which
recognizes dryer operation and activates the dryer exhaust fan from an independent electrical
circuit. This eliminates connections through the dryer circuit which may void the manufacturers’
warranty as well as manual systems which require the attention of the operator or costly current/
temperature sensing systems.
The electricity to the dryer exhaust fan is connected in series through a normally closed terminal
on the switch. A pressure tap is connected to a fitting on the side of the switch. When the dryer
begins operation, positive pressure in the duct causes the switch diaphragm to expand, closing
the circuit to the dryer exhaust fan. An integral delay-on-break timer in the switch will cycle the
fan on for intervals of 10 minutes. This will continue until the dryer has stopped and the timer
delay period has lapsed. Drying cycles, the dryer exhaust fan, the delay timer and the pressure
switch are not adversely affected by the starting/stopping intervals.