42
440 01 6201 00B
Specifications subject to change without notice.
Representative drawing only, some models may vary in appearance.
TO CODE--APPROVED DRAIN OR CONDENSATE PUMP
Tee
Dry Well
Cap
(water tight
and removable)
Tee
Dry Well
Cap
(water tight
and removable)
Tee
Dry Well
Cap
(water tight
and removable)
Recommend “T” fitting with 4--inch minimum height standpipe (
A
) of same diameter or larger extending upward.
A
A
A
A170122A
Fig. 50 -- Recommended Combustion Air Inlet Moisture Trap
3. For each pipe, multiply the number of elbows by the equiv-
alent length for the type of elbow used. Record the equiva-
lent 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 indi-
vidual 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 13 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:
8. 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.
9. 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 fur-
nace. Try the next larger diameter pipe
.
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 Equivalent 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 pipe lengths of 10 ft. (3 M) or less,
use the smallest allowable pipe diameter. Using a 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 M), any larger diameter vent
pipe shown in Table 13
FOR THAT SIZE FURNACE
may be
used.
