International comfort products C Series Installation Instructions Manual page 47

INSTALLATION INSTRUCTIONS
2. Count the number of elbows for each pipe.
3. For each pipe, multiply the number of elbows by the
equivalent length for the type of elbow used. Record the
equivalent length of all the elbows for each pipe.
4. If a Tee is used on the termination (Alberta and
Saskatchewan, when required), record the equivalent
length of the Tee used.
5. Calculate Total Equivalent Vent Length by adding the
equivalent lengths of the fittings to the lengths of the
individual vent and combustion air pipes.
6. When using polypropylene venting systems with flexible
vent pipes, perform adjustments for the equivalent length
of the flexible vent pipe to the calculated total equivalent
venting system length. See the polypropylene vent
system manufacturer's instructions for details.
7. Select a diameter of vent pipe from Table 14 and note
the Maximum Equivalent Vent Length (MEVL) shown for
that application for that specific furnace input size.
Compare the Total Equivalent Vent Length (TEVL) to the
MEVL:
a. If the Total Equivalent Vent Length is shorter than the
Maximum Equivalent Vent Length for the diameter of
pipe chosen, then that diameter of pipe selected may
be used.
Figure 55 Recommended Combustion Air Inlet Moisture Trap
A
Recommend "T" fitting with 4--inch minimum height standpipe (A) of same diameter or larger extending upward.
Tee
Dry Well
Cap
(water tight
and removable)
440 01 4104 07
NOTE: If the calculated Total Equivalent Vent Lengths results
in different diameter pipes for the vent and combustion air,
select the larger diameter for both pipes.
NOTE: If the Maximum Vent Length for diameter of the pipe
selected is longer than the measured length and the equivalent
length of all the fittings and terminations (TEVL), recalculate
Total Equivalent Vent Length using the next smaller diameter. If
the Maximum Vent Length is still longer than the longer TEVL
of the vent pipe or combustion air pipe, then that diameter of
pipe selected may be used.
When installing vent systems with pipe lengths of 10 ft. (3.0 M)
or less, use the smallest allowable pipe diameter. Using pipe
size greater than required for short venting systems may result
in loss of efficiency, incomplete combustion, flame disturbance,
or flame sense lockout.
For vent systems longer than 10 ft. (3.0 M), any larger diameter
shown in Table 14 for that size model may be used.
A
TO CODE- - APPROVED DRAIN OR CONDENSATE PUMP
Tee
Dry Well
Cap
(water tight
and removable)
Representative drawing only, some models may vary in appearance.
Specifications subject to change without notice.
b. If the Total Vent Length is longer than the Maximum
Equivalent Vent Length for the diameter of pipe
chosen, that diameter pipe MAY NOT be used for
venting the furnace. Try the next larger diameter pipe.
A
Tee
Dry Well
Gas Furnace: N9MSB
Cap
(water tight
and removable)
A170134
47