CFM Corporation 2467 - Manual (Page 7)

7
Dutchwest Natural Vent Gas Heater
30002008
Passing Through a
Combustible Wall or Ceiling
An approved pass-through device is always required
when a vent passes through a combustible wall or
ceiling. Check with the maker of the vent system for
the correct listed devices that are available. A listed
pass-through device is required whether or not the
installation includes decorative pipe around the Type B
venting system. NOTE: It is essential to seal between
the ceiling support (sometimes called a ‘firestop
spacer’) and the decorative pipe, if installed, with a
high-temperature silicone sealant. (Fig. 6)
Complete the venting system installation according to
the manufacturer’s instructions.
Fig. 7 Vent termination window.
Venting Requirements
Venting Runs
A: Vertical installations up to 36 feet (12m) in
height. Up to an 18 ft. horizontal vent run can be
installed within the vent system using a
maximum of two 90-degree elbows or four
45-degree elbows.
B: Vertical installations up to 36 feet (12m) in
height. Up to a 24 ft. horizontal vent run can be
installed within the vent system using a
maximum of two 45-degree elbows.
(Ratio = 2/3, Hor./Vert.)
= Acceptable venting configuration
= Unacceptable venting configuration
NOTE: When venting staight vertical, without an
elbow, a minimum of 8 ft. vertical is required
off the top of the stove.
Horizontal Run (in feet)
V
ertical Run (in feet)
(Measured from top of the unit before any elbow)
36
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
1 2 4 6 8 10 12 14 16 18 20 22 24
A
B
FP567b
Joists
Ceiling
Support
Trim
Collar
Air Space
Listed 4”
(102mm)
B-Vent
Decorative
6” Pipe
High-
Temperature
Silicone
Sealant
Air Space as
Required by
Code
ST361
Fig. 6 A ceiling pass-through, with decorative pipe around
the vent.
High-
Temperature
Silicone
Sealant