Lennox Hearth CAMBRIA 850 - Manual (Page 17)

Figure 28
THE CHIMNEY SYSTEM
Chimney Installation Notes
1. If possible, install an interior chimney as it will provide better perfor-
mance. In areas with continuous temperatures below 0°F (-18°C),
the use of an exterior chimney increases the likelihood of operating
problems such as low draft, high rate of creosoting, and poor start-up
characteristics. Exterior chimneys are also prone to down-drafting
and flow reversal. Installations which are located on lower floors in
the house, such as in a basement, in combination with an outside
chimney, are especially prone to flow reversal.
2. The Lennox Hearth Products fireplace model Cambria™ fireplace is
listed only with Security Chimneys International Ltd 10” dia. chimney
systems model Secure Temp ASHT+ / Nova Temp HT6103+ or AC.
3. A chimney venting a fireplace shall not vent any other appliance.
4. The minimum chimney height is 15 feet (4.6 m) excluding the fire-
place.
5. All chimney installations must include at least one support in order to
be able to take any lateral load. The maximum chimney length that can
be supported by the fireplace is 12 feet (3.7 m) for Secure Temp ASHT+
/ Nova Temp HT6103+ and 26 feet (8m) for AC chimney. In altitude, add
18” (450 mm) to the chimney for every 2000 feet (600 m) above sea
level.
6. The chimney must extend at least 3 feet (915 mm) above its point of
contact with the roof and at least 2 feet (610 mm) higher than any
wall, roof or building within 10 feet (3m) of it (Figure 28).
7. If the chimney extends higher than 5 feet (1500 mm) above its point
of contact with the roof, it must be secured using a roof brace.
8. A rain cap must be installed on top of the chimney. Failure to install
a rain cap may cause corrosion problems.
9. Cut and frame square holes in all floors, ceilings, and roof that the
chimney will go through to provide a 2” (50 mm) clearance between
the chimney and any combustible materials. Do not fill this 2” space
with insulation or any other combustible material.
10. Portions of the chimney which may extend through accessible spaces
must be enclosed to avoid contact with combustible materials or
damage the chimney.
Ten (10) Feet
3.1 Meters
Three (3) Feet
.9 Meters
Minimum
Two (2) Feet
.6 Meters
Minimum
CHIMNEY MODEL SqUARE HOLE
SIZE OPENING
Secure Temp ASHT+
Nova Temp HT6103+
16-3/8 in. (416 mm)
AC: 17 in. (432 mm)
Note: See Table 3 for Sloped Roof Framing
Table 2 - Flat Roof Framing
Figure 29 - Roof Framing
Note: 2" clearance to combustibles around chimney components re-
quired.
Note: Blown or fill type insulation materials must not be in contact with the
fireplace or in the enclosure frame as described in ‘’Enclosure’’ section.
Note: Local codes may not require firestopping at the ceiling levels for
outside chase installations. However, it is recommended for safety and
the reduction of heat loss.
CHIMNEY INSTALLATION INSTRUCTIONS
1. Cut and frame the holes in the ceiling, floor and roof where the chimney
will pass (see Figure 29). Use a plumb-bob to line up the center of
the holes. The sizes are indicated in Table 2 for the floor and ceiling
holes and Table 3 (Page 19) for the roof holes.
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
17