Osburn OB04002 User Manual
Page 52
Stratford
Fireplace Installation and Operation Manual
52 _____________________________________________________________________
There are two reasons why the chimney
in the house at right will cold backdraft
when it is cold outside and there is no fire
burning in the fireplace. First, the
chimney runs up the outside of the
house, so the air in it is colder and denser
than the warm air in the house. And
second, the chimney is shorter than the
heated space of the house, meaning the
negative pressure low in the house will
pull outside air down the chimney,
through the fireplace and into the room.
Even the finest fireplace will not work
well when connected to this chimney.
8.5
CHIMNEY INSTALLATION NOTES
1.
If possible, install an interior chimney as it will provide better performance. In areas with
continuous temperatures below
−
18
°
C (0
°
F), 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 outside chimney, are especially prone to flow reversal.
2.
The Stratford is listed only with chimney systems described in TABLE 2 - LISTED CHIMNEYS
FOR YOUR STRATFORD.
3.
A chimney venting a fireplace shall not vent any other appliance.
4.
The minimum chimney system height for a straight installation is 15 ft. (4,6 m).
5.
All chimney installations must include at least one support. Reducing the amount of chimney
weight on the fireplace will help avoid the noise created when the fireplace expands. This can
be achieved by having the chimney supported by the supports. The maximum chimney length
that should be supported by the fireplace is 9 ft. (2.75 m) for 2" Solid Pack Chimney and 12 ft.
(3.7 m) for 1" Solid Pack Chimney.
6.
The chimney must extend at least 3 ft. (92 cm) above its point of contact with the roof and at
least 2 ft. (61 cm) higher than any wall, roof or building within 10 ft. (3.1 m) of it. See the
figures on point 11 bellow to determine the configuration that applies to your roof (flat or
sloped roof and the distance between the chimney and the highest point of the roof and/or
the nearest chimney).
7.
Deviations should be avoided whenever possible, especially the most pronounced. Each
deviation adds some restriction to the chimney system and may lead to draft problems.