Lennox Hearth CAMBRIA 850 - Manual (Page 15)

Figure 24
Figure 25
Aluminum Tape
Insulation
Blower
Tightening Collar
Flex 5” Diameter
Adaptor
Insulated
Flex Pipe
B) Attach the 5” flexible pipe, using the collars provided. Important: Make sure that the plastic
wrapping around the flexible pipe will not be in contact with the fireplace.
C) Route the flexible pipe to the chosen location. The ducting system can be installed either in an
upper room or in a lower room.
D) Attach the flexible pipe to the blower, using the collars (Figure 25).
E) Fix the back draft damper to the blower outlet.
F) Attach a flexible pipe to the fan / flexible pipe adapter (square to round) and stretch it up to the
location where the heat is required.
G) At that point, the flexible pipe can be attached to any air distribution grill.
H) Install the blower heating and cooling thermostat (HCTW) in that part of the house to be heated
by the hot air duct. The thermostat can be switched to a cooling thermostat and installed in
the same room as the unit. This thermostat will turn on the blower when the room where the
fireplace is located becomes too hot.
This option requires electricity. Make sure that the connections to the blower have been made ac-
cording to the local codes and comply with their requirements (see instruction provided with the
thermostat). For more information regarding central forced air kit, refer to the BISFWK-1 installation
sheet provided with the kit.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
15
The duct system must be installed respecting
the following:
1. Remove the plates closing up the 8” (203mm)
diameter holes on top of the fireplace. Then,
cut the insulation in order to obtain two 8”
(203mm) diameter openings. Fix the adap-
tors on the fireplace openings by turning
clockwise (see Figure 21).
2. Maintain at least a 2” (50 mm) clearance
between the ducts and any combustible
material; the required hole size is 13” x 13”
(330 mm x 330 mm).
Exception: For the grills, the framing
can be 10-3/4” x 10-3/4” (275 mm x
275 mm) to provide the clearance as
required by the integral spacers on the
double outlet duct system.
3. The maximum number of elbows in a run
of duct is two.
4. Maintain at least 6-1/2” (160 mm) clearance
from the outlet grill framing to a combustible
ceiling, side wall or mantel.
5. When traversing a combustible wall or floor,
a firestop must be installed at the wall or
floor penetration. The hole size must be 13”
X 13” (330 mm x 330 mm).
6. Do not connect the hot air ducts to a central
heating system. Malfunction of the heating
system’s fan will cause the fireplace to
overheat. A furnace duct is only single wall
and not double wall as is required for the
Cambria™ fireplace hot air exhaust.
7. Use only Lennox Hearth Products grills and
components as described in this manual.
Other grills or registers may be too restrictive
and may overheat the fireplace or ceiling.
8. Do not use insulated flexible ducts as they
will overheat.
9. Do not use tees or any other components
than the ones specifically listed here.
10. All ducts must extend upwards or horizon-
tally. Never route the ducting downwards.
11. The hot air outlet grills must be installed with
the louvers pointing downwards in order to
prevent overheating adjacent ceilings.
Central Forced Air Kit
The knock-outs provided on the back and on
the sides of the Cambria fireplace allow the con-
nection of insulated flexible pipe which enables
you to heat adjacent rooms up to 50 feet from
the fireplace hot air outlet.
The ducting system must be installed as de-
scribed below:
A) Fix the adaptor at the back and/or the side
of the fireplace by twist-locking the adaptor
to the fireplace. You can use more than one
outlet on the fireplace (see Figure 24).