Venting - Modine Manufacturing IPT Installation And Service Manual

INSTALLATION

Venting

WARNING
1. Do not join two sections of Type B double wall vent pipe
within the vent system. A compromised pipe joint/liner pipe
may not be detected, resulting in serious injury or death.
2. A built-in combustion air blower is provided – additional
external draft hoods (diverters) or power exhausters are
not required or permitted.
CAUTION
Installation must conform with local building codes or in the
absence of local codes, with Part 7, Venting of Equipment, or
the National Fuel Gas Code, ANSI Z223.1 (NFPA 54) – latest
edition. In Canada installation must be in accordance with
CAN/CGA-B149.1 for natural gas units, and CAN/
CGA-B149.2 for propane units.
General Venting Instructions
The vent pipe may be installed in either a vertical or horizontal
method. Certified vent pipe lengths are as follows:
Table 12.1 - Maximum Vent Length
Input MBH
50, 60, 75, 100
125
150, 175, 200
1. Do not use any vent pipe other than 4" in diameter. Refer
to the National Fuel Gas Code for the minimum material
thickness and composition of the vent material.
2. It is recommended that vent pipes be fitted with a tee with
a drip leg and a clean out cap to prevent any moisture in the
vent pipe from entering the unit. The drip leg should be
inspected and cleaned out periodically during the heating
season.
3. The National Fuel Gas Code requires a minimum clearance
of 6 inches from combustible materials for single wall vent
pipe. The minimum distance from combustible materials is
based on the combustible material surface not exceeding
160°F. Clearance from the vent pipe (or the top of the unit)
may be required to be greater than 6 inches if heat damage
other than fire (such as material distortion or discoloration)
could result.
4. Avoid venting through unheated space when possible. When
single wall pipe does pass through an unheated space, insulate
runs greater than 5' to minimize condensation. Inspect for
leakage prior to insulating and use insulation that is
noncombustible with a rating of not less than 600°F. Install a
tee fitting at the low point of the vent system and provide a drip
leg with a clean out cap as shown in Figure 12.1. The drip leg
should be cleaned annually.
12
Maximum Vent Length (ft.)
(2) 90° (1) 90° (0) 90°
elbows elbow elbow
20' 25' 30'
30' 35' 40'
40' 45' 50'
Figure 12.1 - Vertical Venting
2' Min.
1' Min.
Drip Leg
Downward slope 1/4" towards drip leg.
* Size according to expected snow depth.
Figure 12.2 - Construction through Combustible Roof
5. Where the vent passes through a combustible wall or floor or
ceiling, a listed metal thimble 4" greater than the vent
diameter is necessary. If there are six feet or more of vertical
vent pipe in the open space between the unit heater and
where the vent pipe passes through the floor or roof, the
thimble need only be 2" greater than the diameter of the vent
pipe. If a thimble is not used, all combustible material must be
cut away to provide a 6 inch clearance. Any material used to
close an opening must be noncombustible. Vent pipes must
be adequately supported and sealed with a 600°F RTV
silicone sealant.
6. Units must be vented with single wall vent pipe, although
Type B vent can be used to terminate the vent system. The
Type B double wall vent must be one continuous section.
Under no circumstances should two sections of double wall
vent pipe be joined together within one vent system due to
the inability to verify complete seal at inner pipes. See Figure
12.2.
7. All vents must be terminated with one of the following
approved vent caps: Gary 1092 or equivalent.
8. Do NOT vent this appliance into a masonry chimney.
9. Do NOT use dampers or other devices in the vent pipes.
10. Do NOT use PVC pipe.
11. Precautions must be taken to prevent degradation of
building materials by flue products.
12. The top of the vertical stack should extend at least 2' above
any portion of a building within a horizontal distance of 2'.
13. For pitched roof vertical venting, refer to Figure 13.1 and
Table 13.1 for the vertical distance that the cap must extend
above the pitched roof.
14. Single wall vent pipe must not pass through any attic, inside
wall, concealed space, or floor.
9-511
Listed cap
*
See Figure 12.2