NOTE: If you have an existing hot air system, you
may safely ‘tie in’ to this hot air system. However, no
hot air duct is to be connected to the return air of
another central heating system.
6. Connect the INLET of the blower to the ducting
coming from the fireplace, using 8” diameter metal
ducting (rigid or flex). Any other size will not work
properly. Use only metal ducting between the fire-
place and the blower. You may use plastic ducting
after the blower, provided the temperature rating of
the ducting is at least 250° F. Do not use plastic
ducting in a chase.
NOTE: The central heat ducting may be run at a 0”
clearance to combustibles.
7. To install the blower (for the FDHB6 only): attach
the noise reduction collars to either side of the
blower using 1/2” self-tapping screws.
8. Ductwork can then be run to the desired rooms. Up
to six 5" or five 6" diameter runs can be installed
from this system.
NOTE: Runs must be balanced as air travels along
the path of least resistance. Balance the airflow by
diameter and length of runs. Longer runs should have
larger diameters. Houses vary in size and layout, so
duct systems must be specifically designed for each
home. The diagrams on this sheet are examples only.
The cross sectional area of the distribution system
must total at least 50 square inches. If you have more than
50 square inches, some of the system may be shut off, but
there must always be 50 square inches of ducting open at
all times. For example, if 5" pipe is used for distribution, the
cross section of each is 20 square inches. The minimum
allowable ducting would be three runs of 5" pipe.
Page 28
2 noise reduction
collars
Central heat variable
speed blower
Mounting
bracket
Blower speed
control
Figure 25: Central heat blower kit (FDHB6)
Air circulation through fireplace and home with central heat
blower in the ‘OFF’ cycle.
Air circulation through fireplace and home with central heat
blower in the ‘ON’ cycle (blower thermostat calling for heat).
Figure 26: Central heat ducting options (single floor)
Warm air
registers
Ideal blower
thermostat location
Central heat
blower
Hot air
Cool air
Back draft
damper
(FDHC6-1)
Central heat control
kit (FDHC6)
Thermostat
Thermal
switch
Figure 24: Central heating kits (FDHC6-1 and FDHC6)
5. Locate the blower in a convenient location. The blower
may be installed vertically or horizontally. The horizontal
installation can utilize either the supplied mounting
bracket or, if you want to install the blower farther away
from the ceiling, you can use plumber’s strapping. A ver-
tical installation must include the mounting bracket.
OPEL AP
