Installation; Venting - Modine Manufacturing PTX Installation And Service Manual

INSTALLATION - VENTING
W ARNING
1. Gas fired heating equipment must be vented - do not
operate unvented.
2. A built-in power exhauster is provided - additional external
power exhausters are not required or permitted.
3. If an existing heater is being replaced, it may be
necessary to resize the venting systems. Improperly sized
venting systems can result in vent gas leakage or the
formation of condensate. Refer to the National Fuel Gas
Code ANSI Z223.1 (NFPA 54) or CSA B149.1 - latest
edition. Failure to follow these instructions can result in
serious injury or death.
4. Under no circumstances should two sections of double
wall vent pipe be joined together within one horizontal
vent system due to the inability to verify complete seal of
inner pipes.
CAUTION
Installation must conform with local building codes or in the
absence of local codes, with the National Fuel Gas Code,
ANSI Z223.1 (NFPA 54) - latest edition. In Canada installation
must be in accordance with CSA B149.1.
Model PTX/BTX unit heaters must be vented with the proper
passageway as described in these instructions to convey flue
gases from the unit or the vent connector to the outside
atmosphere. The venting instructions are organized in sections,
based on installation type. The sections are identified as follows:
Section Applicable Installation Instructions by Vent
System Type
A General instruction for ALL installations
B VERTICAL CATEGORY I vent systems j
C HORIZONTAL CATEGORY III vent systems j
D
Vertical 2-Pipe vent systems j
E
Horizontal 2-Pipe vent system j
HORIZONTAL AND VERTICAL CONCENTRIC
F
vent systems j
 The differences between Vertical and Horizontal vent systems will be identified
in "Section A - General Instructions - All Units".
Section A - General Instructions - All Units
A1. If the unit heater being installed is replacing existing
equipment and using the existing vent system from that
equipment, inspect the venting system for proper size and
horizontal pitch, as required in the National Fuel Gas Code,
ANSI Z223.1 (NFPA 54) or CSA B149.1 Installation Code -
latest edition and these instructions. Determine that there is
no blockage or restriction, leakage, corrosion and other
deficiencies, which could cause an unsafe condition.
A2. The vent pipe should be galvanized steel or other suitable
corrosion resistant material. Follow the National Fuel Gas
Code for minimum thickness of vent material. The minimum
thickness for connectors varies depending on the pipe
diameter. Do not vent unit with PVC or other forms of
plastic venting material.
A3. All heaters come with factory installed vent and combustion
air adapters for attaching the vent pipe to the heater (see
Table 6.1). Attach the vent pipe to the adapter with
3-corrosion resistant screws. (Drill pilot holes through the
vent pipe and adapter prior to screwing in place). Vent
pipe much not be smaller than the connector size.
6
A4. Refer to Table 6.1 for total equivalent vent pipe lengths,
making the vent system as straight as possible. The
equivalent length of a 90° elbow is 5 feet for 4 inch diameter
and 7 feet for 6 inch diameter.
Table 6.1 - Vent Pipe Diameters, Transitions, and
Total Equivalent Vent Pipe Lengths For 1 and 2 pipe
Horizontal and Vertical Venting Systems
Model Vent Pipe
Size Diameter
150
175-200
250-400
A5. Horizontal sections of vent pipe are to be installed with an
upward or downward slope from the appliance of 1/4 inch
per foot and suspended securely from overhead structures
at points not greater than 3' apart.
A6. Fasten individual lengths of vent together with at least three
corrosion resistant sheet metal screws.
A7. Keep single wall vent pipe at least 6" from combustible
materials. For double wall vent pipe, follow the vent pipe
manufacturer's clearances to combustibles. 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" if heat damage other than fire
could result (such as material distortion or discoloration).
A8. Avoid venting through unheated space when possible.
When venting does pass through an unheated space or
if the unit is installed in an environment that promotes
condensation, insulate runs greater than 5' to minimize
condensation. Inspect for leakage prior to insulating and use
Vent Type
insulation that is noncombustible with a rating of not less
than 400°F. Install a tee fitting at the low point of the vent
Both
system and provide a drip leg with a clean out cap as
Vent Only
shown in Figure 9.1.
Vent Only
Figure 6.1 - Venting Through Combustible Roof or Wall
Combustion
Air and Vent
Single Wall Vent Pipe
Combustion
Air and Vent
Combustion
Air and Vent
Single Wall Vent Pipe Terminating
with Double wall vent pipe. 
Single Wall Vent Pipe
 See Instruction A12 for attaching single wall pipe to double wall pipe.
6-534.1
Vent Type
Minimum
Vent
Combustion
Air and Vent
Only
4" 3' 5'
4" 3' 5'
6" 3' 5'
Double Wall Vent Pipe 
Specified
Terminal
Flashing
Listed
Thimble
Single
Wall
Clearance Specified
by Type B Vent Mfg.
Listed
Thimble
Maximum
Vent
Combustion
Air and Vent
Only
50' 25'
70' 50'
70' 50'
Specified
Terminal
Flashing
Clearance Specified
by Type B Vent Mfg.
Double
Wall
Specified
Terminal
Single
Wall
Specified
Terminal