18
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
HORIZONTAL VENT FIGURES/TABLES
Note: Two 45 degree elbows may be used in place of one 90 degree elbow.
The same rise to run ratios, as shown in the venting figures for 90 degree
elbows, must be followed if 45 degree elbows are used.
Note: It is very important that the horizontal/inclined run be main-
tained in a straight (no dips) and recommended to be in a slightly
elevated plane, in a direction away from the fireplace of
1/4" rise per
foot (20 mm per meter) which is ideal, though rise per foot run ratios that
are smaller are acceptable all the way down to at or near level.
Note: Secure Vent components (rigid vent pipe and terminal) are
shown in the figures; Secure Flex components (flexible vent pipe and
terminal) may also be used.
WARNING: UNDER NO CIRCUMSTANCES MAY SEPA-
RATE SECTIONS OF CONCENTRIC FLEXIBLE VENT PIPE
BE JOINED TOGETHER.
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Note: SV4.5VF (Secure Vent), SF4.5VF (Secure Flex) firestop/spacer
must be used anytime vent pipe passes through a combustible floor or
ceiling. Lennox MPLDV35"/40" & 45" models require 5" clearances to
combustibles above horizontal vent runs when the centerline of the
horizontal vent run is at or below 48" (1219 mm) above the fireplace top
wrapper. In all other instances, with these three models and with the
MPLDV30 in all instances, the clearance to combustibles above horizon-
tal vent runs is 3". Please note that to facilitate the 5" clearance when
required, we have two 5" clearance firestops. The SV4.5HF5 is for use
with rigid (Secure Vent™ ) and the SF4.5HF5 is for use with (Secure
Flex™ ). These firestops should be used whenever horizontal vent runs
meeting the use requirements detailed above, penetrate walls separating
occupied rooms in a house.
Each of our horizontal terminations are shipped with a standard 3"
clearance horizontal firestop. In ALL cases this firestop may be used at the
exterior wall regardless of any circumstances that may require the 5"
clearance to combustibles above the horizontal vent component. The
firestop provided with the termination is not specific for use with any
particular clearance height.
The SV4.5HF or SF4.5HF firestop provided with each termination can be
used as shown in Figure 29 when fitted at the exterior wall adjacent to the
termination.
3”
1”
1”
1”
Stud
Framing
SV4.5HF/SF4.5HF
Firestop
Top
Spacer
5”
1”
1”
1”
Stud
Framing
Top
Spacer
SV4.5HF/SF4.5HF
Firestop
3” Clearance
5” Clearance
Figure 29