Carrier 59SC2A - Page 49

Table 17 - Maximum Equivalent Vent Length - Ft. (M)
4501 to 10,000 Ft. (0 to 1370 M) Altitude
NOTE: Maximum Equivalent Vent Length (MEVL) includes standard and concentric vent termination and does NOT include elbows.
Use Table 16 - Deductions from Maximum Equivalent Vent Length to determine allowable vent length for each application.
Altitude
FT (mM) 5
Unit Size
40,000 33 (10.1) 171 (52.1) 196 (59.7)
4501 to 5000 .
(1370 to ,
1524) ,
5001 to 6000
(1524 to
1829)
59SC2A
6001 to 7000
(1829 to
2134)
7001 to 8000
(2134 to
2438)
8001 to 9000
(2438 to
2743)
9001 to
10,000
(2743 to
3048)
NOTES:
1. Use only the vent pipe sizes shown for each furnace. It is NOT necessary to choose the smallest diameter pipe possible for venting.
2. NA — Not allowed. Pressure switch will not close, or flame disturbance may result.
3. Total equivalent vent lengths under 10’ for 40,000 BTUH furnaces from 0 to 2000 ft. (0 to 610 M) above sea level require use of an outlet choke plate .
Failure to use an outlet choke when required may result in flame disturbance or flame sense lockout.
. Not all furnace families include 140,000 BTUH input models.
. Vent sizing for Canadian installations over 4500 ft (1370 M) above sea level are subject to acceptance by local authorities having jurisdiction.
. Size both the combustion air and vent pipe independently, then use the larger size for both pipes.
. Assume the two 45° elbows equal one 90° elbow. Wide radius elbows are desirable and may be required in some cases.
. Elbow and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
. The minimum pipe length is 5 ft. (2 M) linear feet (meters) for all applications.
. Use 3-in. (76 mm) diameter vent termination kit for installations requiring 4—in. (102 mm) diameter pipe. OO
MON
Oost
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