LG P1BRENTW-A - Manual (Page 20)

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The duct system must be installed respecting the following:
1. Remove the plates closing up the 8" dia. holes on top of the fireplace. Then, cut the
insulation in order to obtain two 8" dia. openings. Fix the adaptors on the fireplace
openings by turning clockwise (figures 13 and 14).
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 #1: For the grills, the framing can be 10 ¾" x 10 ¾" (275 mm x 275 mm) to
provide the clearance as required by the integral spacers on the double outlet duct system.
Exception #2: For the single outlet, the framing must be 8 ¼" x 32 ¼" (210 mm x 820
mm) or as required by the integrated spacers. At no time should any combustible facing
material such as panelling cover over any part of the grill face.
3. The maximum number of elbows in a run of duct is two.
4. Maintain at least 6 ½" (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 BRENTWOOD hot air exhaust. For this type of
installation refer to “Central Forced Air Kit” on the next page.
7. Use only Lennox Hearth Products grills and components as described in this manual.
Other grills or registers, for example, 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 horizontally. 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.
12. Always install the two outlet grills when using the double hot air outlet kit and blocking
the upper louver of the fireplace.