Installation Instructions

Section 2
Model O Oval
Basic Vent Structure
AmeriVent (Model O) Oval Gas Vent is available in sizes 4,
5, and 6-inch. The individual sizes reflect the flow rate
capacities equivalent to 4-inch, 5-inch, and 6-inch Round
Type B Gas Vent. The joint of the Model O Type B Oval
Gas Vent takes up one inch when assembled. The Model
O Gas Vent is UL-listed for the following applications and
clearances to combustibles as shown in Table 6.
Type B Oval Gas Vent
Type B Oval Gas Vent is available in sizes 4, 5, and 6-inch,
and requires a 1-inch clearance to combustibles. This
includes all Vent Sections, Elbows, Tees, and Adapters.
When used as Type B Gas Vent, Model O must follow all of
the same requirements as round Type B Gas Vent, such as
the necessity of using firestops at each floor level. See
Section 1.
Type B 2 x 4 Gas Vent - 4" or 5" Oval
Four- and five-inch AmeriVent (Model O) Gas Vent may be
installed within a standard 2x4 stud wall if all the following
conditions are met.
1. Arrows on AmeriVent parts should always point up.
2. Stud bay must be a 16-inch, on-center stud bay.
3. 2x4 studs must be a minimum of 3.5 inches deep.
4. There must be nothing else in the stud bay other than
the Vent Section. This includes any type of
insulation.
5. The Firestop Spacer (FS) must be installed at each
floor level. See Figure 17.
NOTE: Only the straight Vent Pipe Sections, with or
without the Oval Tee, may be used inside the stud
bay with reduced clearances to combustibles.
See Figure 17.
Installation of Type B 2 x 4 Gas Vent
1. Cut out the ceiling plate in the space where the Vent
is to be installed.
2. Nail a 2x4 support (A) at the desired height between
the studs. See Figure 17.
3. Attach the Tee Support (B), the Tee (C) with the
Oval Tee Cap, and the Vent Pipe (D) as shown on
Figure 17.
4. At each floor level above the Tee, install the Firestop
Spacer (E) as shown in Figure 17.
NOTE: Provide at least a 1-inch clearance around the Tee
branch where it passes through combustible wall
construction.
Type B-W Gas Vent - 4" Oval
AmeriVent (Model O) Gas Vent may be installed within a
standard 2x4 stud wall if all the following conditions
are met.
1. Arrows on AmeriVent parts should always point up.
2. Stud bay must be a 16-inch, on-center stud bay.
3. 2x4 studs must be a minimum of 3.5 inches deep.
10
AmeriVent Round and Oval Gas Vent
Installation Instructions
Figure 17
A
B
C
D
E
Underwriters Laboratories-listed
Minimum Clearances to Combustibles
Oval AmeriVent
Description
Type Minimum Clearance
4", 5" and 6" B 1"
4" and 5"
(when installed in 2x4
stud wall with other-
than-recessed heater)
B2x4
Clearances as determined
by use of 4OFS or 5OFS
firestop spacers at each
ceiling level
4"
(when installed in 2x4
stud wall with
recessed heater)
B-W
Clearances as determined
by use of 4OHD hold-down
plate, 4OPS ceiling plate
spacers, and 4OFS firestop
spacers
Table 6