Minimum And Maximum Wall Thickness; Vent Pipe Sizing - Watts AERCO EXT Installation, Operation & Maintenance Manual

Modulex EXT Commercial Series
CHAPTER 4: Installation Instructions
The terminal should be located where dispersal of combustion products is not impeded and with due
regard for the damage or discoloration that might occur to building surfaces in the vicinity. In certain
weather conditions condensation may also accumulate on the outside of the air inlet pipe. Such
conditions must be considered and, where necessary, insulation of the inlet pipe may be required. In
cold and/or humid weather water vapor may condense when leaving the vent terminal.
The terminal must not be located in a place likely to cause a nuisance.
Maintain 12" of clearance above the highest anticipated snow level or grade, whichever is greater.
Please refer to your local codes for the snow level in your area.
The whole route of the vent system must be installed upwards, NOT completely nor partly downwards.

4.22.2 Minimum and Maximum Wall Thickness

The label at right, which is placed on the unit, indicates the minimum
and maximum wall thickness through which venting is allowed to
penetrate horizontally. However, if venting is vertical, then there is no
minimum wall thickness.

4.23 Vent Pipe Sizing

The maximum length is the combined length of straight horizontal and vertical runs, and the equivalent
straight length of fittings. The required lengths for each boiler are as follows:
NOTE: The examples referenced in the table below are on the next page.
TABLE 4-4: MODULEX EXT Vent and Piping DIAMETER Chart
MODEL
EXT 1500 2S
EXT 2300 2S
EXT 2600 2S
EXT 3000 2S
TABLE 4-5: MODULEX EXT Vent and Piping LENGTH Chart
MODEL
DIAMETER
EXT 1500 2S
EXT 2300 2S – EXT
3000 2S
NOTE: The flue system must be installed in accordance with the local and national Standards.
OMM-0160_A • DRAFT
NO. OF VENT DIAMETER
MODULES INCHES (MM)
4 10" (254 mm)
6 12" (304 mm)
7 12" (304 mm)
8 12" (304 mm)
SHARP 90°
VENT PIPE ELBOW
EQUIVALENT
FEET (M)
10" 13 Feet
(254 mm) (4 m)
12" 13 Feet
(304 mm) (4 m)
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
MAX. VENT EQUIV.
FEET (M)
EXAMPLES 1 & 2
100 ft. (30 m)
100 ft. (30 m)
100 ft. (30 m)
100 ft. (30 m)
SWEEP 90°
45° ELBOW
ELBOW
EQUIVALENT
EQUIVALENT
FEET (M)
FEET (M)
7 Feet 5 Feet
(2 m) (1.5 m)
7 Feet 5 Feet
(2 m) (1.5 m)
MAX. VENT EQUIV.
FEET (M)
EXAMPLES 3 & 4
6 + 6 (1.8 + 1.8)
6 + 6 (1.8 + 1.8)
6 + 6 (1.8 + 1.8)
6 + 6 (1.8 + 1.8)
MAXIMUM
LENGTH
EQUIVALENT
FEET (METERS)
100 Feet
(30 m)
100 Feet
(30 m)
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