Modine HD Serie Manuel D'installation Et D'entretien page 11

InsTAllATIon - venTIng
section d – Horizontal, Category I vent system
Installation (residential only)
D1. This section applies to horizontally vented Category I
vent systems and is in addition to "Section A – General
Instructions – All Units".
D2. Units can be vented with a Horizontal Category I vent
system for residential installations only. If the installation
is non-residential, please refer to "Section C – Horizontal,
Category III Vent System Installation" for proper venting
instructions.
D3. All heaters installed with Category I horizontal vents must
be equipped with a vent transition to 4" or 5" vent diameter
for sizes 30-75 and 6" for sizes 100-125. All portions of the
vent system shall consist of 4", 5", or 6" diameter single wall
vent pipe and fittings. The requirements for selection of vent
diameter are shown in Table 11.1.
Table 11.1 Horizontal Category I vent system limitations
model vent maximum
size Terminal no. of
elbows
30 TEE 1
TEE 1
2 ➀
Cap
2 ➀
Cap
2 ➀
Cap
45 TEE 1
2 ➀
Cap
2 ➀
Cap
0 TEE 1
2 ➀
Cap
75 TEE 1
2 ➀
Cap
100 TEE 1
Cap 2
125 TEE 1
Cap 2
➀
One of the two allowed elbows is required to create the vent extension shown
in figures 12.3 and 12.4.
➁
The vertical rise gained from an elbow is 4". Therefore, 4" may be subtracted
from the length of vertical pipe needed in the vent extension. If the minimum
vertical rise required is 4" you do not need to add a section of vertical pipe to
the vent extension.
D4. All seams and joints of the single wall pipe must be sealed
with metallic tape or silastic suitable for temperatures up to
400°F. Wrap the tape two full turns around the vent pipe.
One continuous section of double wall vent pipe may be
used within the vent system. Refer to instruction A10 in
"Section A – General Instructions – All Units" for attaching
double wall pipe to single wall pipe.
minimum maximum
vertical rise Horizontal diameter
from vent
Horizontal (in) length (ft)
0 10
0 5
4 ➁
10
12 ➁
5
18 ➁
10
0 10
12 ➁
10
18 ➁
5
0 10
15 ➁
10
0 5
18 ➁
5
0 10
30 5
0 10
30 5
D5. The maximum length of the horizontal run of the vent
shall be limited to the length listed in Table 11.1. The vent
terminal for a horizontal category I vent may be either a
standard vent TEE or a Gary Steel 1092. The maximum
number of elbows, slope of the horizontal section, and
minimum vertical rise from horizontal vent pipe for each
configuration is listed in Table 11.1.
• When using a standard vent TEE, the preferred
orientation is for the open ends of the TEE to be oriented
horizontally. In this orientation, the minimum clearance
to combustibles is 6" above the TEE to the eave. If the
TEE is oriented vertically, the minimum clearance to
combustibles is 27" above the TEE to the eave. Refer
to Figure 12.1. The vent TEE should incorporate a bird
screen made from corrosion resistant material. The
individual strands of mesh in the bird screen must be
located at least 1/4" apart.
• When using a vent cap, the minimum clearance to
vent
combustibles is 6" above the cap to the eave. Refer to
Figure 12.1.
(in)
D6. When vented horizontally, maintain a 1/4" per foot rise away
from the heater. Place a drain tee and clean out near the
5
vent connector. See Figures 11.1 and 12.3. Where local
4
authorities have jurisdiction, a 1/4" per foot downward slope
5
is acceptable. The Condensate is allowed to drip out of the
end when using a TEE terminal. See Figure 12.2. When
4
using a vent cap with an extension, a 3/8" diameter hole is
4
drilled in the low point of the vent by the installer exterior to
5
the space to allow condensation drainage. See Figure 12.4.
5
4
figure 11.1
Horizontal Category I venting -Tee With upward pitch
5
5
5
5
6
Vent tee
6
12" Min
6
6
D7. If the unit will not be common vented with other appliances,
then proceed to the section titled "Installation - Gas
Connections". Otherwise, proceed to page 13.
6-583.2
Exterior wall
1/4" Slope per foot up
towards termination
Listed thimble
Vent transition
Clean out/Drip leg
Maximum vent length
as shown in Table 11.1
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