14
O
UTSIDE AIR ASSEMBLY
(
FIREPLACE AND
AC
CHIMNEY
)
The outside air assemblies are mandatory for the fireplace and the AC chimney
.
During operation, the fireplace requires air for combustion and draws air out of the house. It may starve
other fuel burning appliances such as gas or oil furnaces. As well, exhaust fans and fan driven appliances
may compete for air, causing a negative pressure in the home, resulting in smoke entering the home from
the fireplace. This situation is aggravated in modern airtight houses. To overcome this potential
problem, we
require the installation of an outside air assembly
to provide combustion air to the
fireplace.
O
UTSIDE AIR INSTALLATION
(
FIREPLACE AND
AC
CHIMNEY
)
The outside air assembly must be installed according to the following guidelines:
1.
The maximum length of 4" I.D.(100 mm) insulated flexible duct is 20 ft (6.1 m ). If a longer duct is
required, use a 6" I.D (150 mm) insulated flexible duct. The maximum length is 40 ft (12 m ). Refer
to figures 8b and 8c for connections.
2.
The duct and register may be installed above or below floor level.
3.
The outside air register must not be installed more than 10 feet (3.05 m) above the base of the
fireplace.
4.
The outside air assembly must draw air from outside the house. It must not draw air from the attic,
the basement or a garage (see fig. 15 page 19).
5.
Locate the outside register where it will be well away from automobile exhaust fumes or other vents.
6.
The outside air register should be installed where it is not likely to be blocked by snow or exposed to
extreme wind
7.
It is recommended to install the outside air register at floor level. However, if you must raise the air
register above the fireplace level, you will have to make a loop to the floor with the flexible pipe to
prevent from causing a draught in the outside air register (see Figure 8a).
Figure 8a
Figure 8b
Figure 8c
