Hearth and Home Technologies Hudson Bay Direct Vent Gas Appliance HUDBAY-FS - Manual (Page 11)

10/08 Page 11 Quadra-Fire • Hudson Bay • 7003-121 Rev. i
D. How to Use the Vent Graph E. Venting Guidelines
Figure 5.2
NOTE: I F YOUR INSTALLATION FALLS WITHIN A SHADED
AREA ON THE GRAPH, THE DAMPER MUST BE USED.
(In the Commonwealth of Massachusetts, the word damper
shall be replaced with the words flue restrictor.)
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.
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).
VERTICAL DISTANCE
FROM APPLIANCE TO
TO THE 90° ELBOW
TOTAL HORIZONTAL RUN TO OUTSIDE OF EXTERIOR WALL (INCLUDING ELBOWS)
EX. 2
EX. 1
11" 2' 4' 6' 8' 10' 12' 14' 15'
30'
28'
26'
24'
22'
20'
18'
16'
14'
12'
10'
8'
6'
4'
2'
0'
(MAX) (MIN)
40'
38'
36'
34'
32'
NOTES
The maximum horizontal vent run is 15 ft. (5m) with a minimum
vertical vent rise of 10 ft. (3m).
The minimum horizontal vent run is 11 in. (279mm).
Minimum wall thickness is 4 in. (102mm). Maximum wall
thickness is 20 in. (508mm).
Horizontal sections require a 1/4 in. (6mm) rise for every 12
in. (305mm) of horizontal travel.
Exterior Vent Diameter = 6 5/8 in. (168mm); Inner Vent Diam-
eter = 4 in. (101mm)
Horizontal sections require noncombustible support every 3
ft. (914mm), e.g. wall straps.
Maximum 90° elbows for horizontal termination is 3.
Maximum 90° elbows for vertical termination is 4.
Example 1: If the vertical dimension from the top of the
appliance is to the center of the 90° elbow is
7 ft. (2m), the horizontal run to the outer wall
flange must not exceed 12 ft. (4m).
Example 2: If the vertical dimension from the top of the
appliance is 21 ft. (6m), the horizontal run
to the outer wall flange must not exceed 9
ft. (3m).
Example: The use of 3 elbows would reduct the
alowable horizontal run to 9 ft. (3 - 1 = 2
elbows x 3 ft. = 6 ft.; 15 ft. max. - 6 ft. = 9
ft. max.)