(Figures 27 & 28) illustrate two examples of “tying-in” to
existing ductwork. Directing air in the right direction will
reduce reverse flow when the existing furnace blower is off.
Some reverse flow will not cause any problems.
CAUTION: Tie-ins into existing ductwork must be
down stream from the existing furnace.
NOTE: When the central heating blower is in operation, it
removes air from the room containing the fireplace. If this
room can be closed off from the rest of the house (e.g. with
a door), a grill with at least a 100 square inch open area
must be installed to allow the air to return to the fireplace.
Otherwise periodic smoking from the fireplace will result.
9. Wire the blower to a 115-volt, 15-amp breaker through
the thermostat provided. The variable speed switch pro-
vided should be installed in a convenient location near
the fireplace so the blower can be shut off during refuel-
ing. The blower control center should be placed in an
accessible location near the blower. It should be mount-
ed in a 4 x 4 electrician’s box. You have two options of
how you can connect the central heat blower to the
blower control assembly.
a) If you would like the blower to turn on when the thermo-
stat calls for heat, first locate the thermostat in the prin-
cipal room heated by the duct system. Do not install it in
the room where the fireplace is installed. There are yel-
low black and red wires coming out of the relay as
shown in the wiring diagram. Connect the wire from #4
of the terminal block to the black wire and put the wire
connector on the red wire for protection. (See Figures 36
and 37 for schematic wiring diagrams.)
b) If the fireplace is in a small room and/or you would like
the central heat blower to remove air from this room
when it becomes too hot, locate the thermostat in the
room with the fireplace. Connect the wire from #4 of the
terminal block to the red wire and put the wire connector
on the black wire for protection. (See Figures 36 and 37
for schematic wiring diagrams.)
(Figure 29) shows some ways of ducting the hot air from
the blower. You are not restricted in the size of pipe, as
long as the total cross sectional area of all runs combined
is not less than 50 square inches. The diagram shows
alternate blower locations. Only one external blower can
be installed.
Page 30
Alternative blower
location
Noise reduction collars
4” min.
B-vent pipe
5
9
”
m
in
.
Back draft
damper
2 duct
6” diameter runs
Zero clearance
3 duct
5” diameter runs
Blower
Figure 29: Central heat location options
OPEL AP
