Hearth & Home Technologies HUDBAY-FS User Manual

10/08

Page  11

Quadra-Fire  •  Hudson Bay  •  7003-121 Rev. i

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).

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.

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).

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).