GC9S96 Service Manual
SYSTEM OPERATION
15
3”-24” BETWEEN PIPES
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tween joist spaces. If the vent pipe must go below a joist and
then up into the last joist space to penetrate the header, two
45° elbows should be used to reach the header rather than
two 90° elbows.
Direct vent installations require both a combustion air intake
exit through the side of the building or run vertically and
exit through the roof of the building. The pipes may be run
through an existing unused chimney; however, they must
extend a minimum of 12 inches above the top of the chim-
ney. The space between the pipes and the chimney must
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tions must be in the same atmospheric pressure zone. Refer
to Vent/Flue and Combustion Air Pipe - Termination Loca-
tions or Concentric Vent Termination section in this manual
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tion construction.