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D. How to Use the Vent Graph
1.
Measure the distance from the top of appliance to the
center of the 90° elbow. On the graph below, draw a
horizontal line from that measurement on the vertical
axis across until it intersects with the slanted line.
2.
From the point of this intersection, draw a vertical line to
the bottom of the graph.
3.
The point at which this line meets the bottom line of the
graph is the maximum length of the horizontal run.
EXAMPLE 1: If the vertical dimension from the center line
of the fl ue vent to the center of the 90° elbow is 7 ft. (2 m),
the horizontal run to the outer wall fl ange must not exceed
13 ft. 2 in. (5m).
EXAMPLE 2: If the vertical dimension from the center line
of the fl ue vent is 21 ft. (6m), the horizontal run to the outer
wall fl ange must not exceed 10 ft. (3m).
4.
Each 90° elbow is equivalent to 3 ft. (914mm) of vent
pipe and each 45° elbow is equivalent to 1 ft. (305mm)
of vent pipe, and must be subtracted from vent pipe
run. A single vertical to horizontal 90° elbow is already
calculated into the allowable 15 ft. (5m) run. Each
additional 90° elbow reduces the maximum horizontal
distance by 3 ft. (914mm).
Example:
The use of 3 elbows would reduce the
allowable horizontal run to 9 ft. (3 - 1 = 2 elbows x 3 ft. =
6 ft.; 15 ft. max. - 6 ft.= 9 ft. max.)
40'
40 ft. (12m)
Maximum Run if
38'
using Stainless
36'
Steel Inner Pipe
Material
34'
32'
30 ft. (9m) Maxi-
mum Run if using
30'
Aluminum Inner
28'
Pipe Material
Flue Restrictor more
26'
CLOSED in this area
24'
Example 2
22'
20'
18'
Vertical Distance
16'
from Appliance Top
o
to 90
Elbow
14'
12'
10'
Example 1
8'
Flue Restrictor
6'
OPEN in this area
4'
2'
0'
11" 2'
(MIN)
TOTAL HORIZONTAL RUN TO THE OUTER
WALL FLANGE (EXCLUDING ELBOWS)
Figure 5.2
Flue Restrictor
50% CLOSED in
this area
4'
6'
8'
10'
Heat & Glo • TIARA I-C • 7066-100 Rev. D • 12/11
E. Venting Guidelines for Horizontal Runs
Standard Horizontal Run
Max Horizontal Run,
Rear Vent
Max Horizontal Run
Max Horizontal Run
o
with 45
Elbow
Min Horizontal Run
Max Wall Thickness
Min Wall Thickness
Exterior Vent Diameter
Inner Vent Diameter
Rear Vent with Vertical
Rise
Horizontal Run requires a 1/4 in. (6mm) rise for every 1 ft
toward the termination.
Horizontal Run requires a non-combustible support every
3 ft (914mm), i.e., plumbing tape
Horizontal Run with Snorkel Kit.
A rear vent configuration with 3 ft. (914mm) maximum
horizontal run with no vertical pipe and with 1/4 in.
(6mm) rise per foot.
• A snorkel kit must be used. Figure 5.3 below and
Figure 5.4 on page 12.
• A derating orifice must be installed. The appropriate
orifice is supplied with the rear vent kit.
C L
Figure 5.3
NOTE: IF YOUR INSTALLATION FALLS WITHIN
A SHADED AREA ON THE GRAPH, THE FLUE
RESTRICTOR MUST BE USED.
INDIVIDUAL INSTALLATIONS MAY VARY.
Percentage closed based on full range of the fl ue restric-
12'
14' 15'
WARNING! Fire Risk!
(MAX)
• Never allow the vent to run downward.
• This could cause high temperatures and may present
the possibility of a house or structure fi re.
3 ft (914mm)
15 ft (5m) when vertical rise is
10 ft (3m
14 in. (356mm)
11 in. (279mm)
20 in. (508mm)
4 in. (102mm)
6-5/8 in. (168mm)
4 inches (101mm)
Min of 2 ft vertical (610mm)
must be used prior to any hori-
zontal run
Snorkel Kit
tor travel.
11
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