Empire Heating Systems PVS18N-3, Owner'S Manual And Installation Instructions

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37873-0-0217 Page 29
Table 3 - Equivalent Vent Length Example (See Figure 48)
EVL = Equivalent Vent Length
EVL must be greater than or equal to 1’
and less than or equal to 50’
EVL = 5’ straight pipe + 90º elbow + 37’ straight pipe + 90º elbow + 2’ straight pipe = 50’
EVL =
5’
(straight pipe) +
3’
(90º elbow) +
37’
(straight pipe)
+
3’
(45º elbow) +
2’
(straight pipe) = 50’
Max Vent Run - 50 ft. Equivalent
When installing a horizontal vent termination, the minimum vent
length protruding from the outside wall is 10 inches (304mm). See
Figure 47.
For venting cap, exhaust with 45° elbow.
Notice: Horizontal discharge 45° elbow must be pointed down-
ward. See Figure 47.
Notice: All horizontal runs require a 1/4” per foot rise to run con-
densation back to the wall furnace.
Notice: For each 45° elbow installed, the length of the run
MUST be reduced by 1.5 feet (45 cm). Reduce the length of the
run three feet (91.4 cm) for every 90° elbow. The vent terminal
elbow does not contribute to the overall vent length measure -
ment.
Figure 47
Single Flue - Straight Out Back
90 ELBOW
°
2’
(61.0cm)
37’
(11.3m)
5’
(1.5m)
VENT TERMINAL
45
° ELBOW
(NOT COUNTED)
3 FEET
FIRST 90 ° ELBOW
3 FEET
SLOPE
SLOPE
Figure 48
Example Calculation Max Vent Run 50 feet
Figure 48 displays a single flue (one-pipe) installation. The first
90° elbow must be considered into the total vent length. The
equivalent length of the second 90° elbow also needs to be add-
ed to the total length, but the third elbow does not since it is the
flue terminal. The total horizontal vent length of the flue system
is seven feet, and the total vertical length is 37 feet. The two 90°
elbows are equivalent to six feet, bringing the total to 50 feet.
VENT EXAMPLES FOR SINGLE FLUE
WALL FURNACE INSTALLATION