Carrier 120 Series - Page 52

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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.
Table 17 – Maximum Equivalent Vent Length -- Ft. (M)
4501 to 10,000 Ft. (0 to 1370 M) Altitude
Altitude
FT (M)
Unit Size
DIRECT VENT (2-PIPE) AND VENTILATED COMBUSTION AIR ONLY
Vent Pipe Diameter
1-1/2 2 2-1/2 3 4
4501 to 5000
(1370 to 1524)
60,000 35 (10.7) 111 (33.8) 198 (60.4) 221 (67.4) NA
80,000 23 (7.0) 85 (25.9) 146 (44.5) 195 (59.4) 216 (65.8)
100,000 NA 40 (12.2) 91 (27.7) 200 (61.0) 222 (67.7)
120,000 NA NA NA 80 (24.4) 211 (64.3)
5001 to 6000
(1524 to 1829)
60,000 37 (11.3) 103 (31.4) 186 (56.7) 207 (63.1) NA
80,000 22 (6.7) 76 (23.2) 137 (41.8) 183 (55.8) 200 (61.0)
100,000 NA 33 (10.1) 85 (25.9) 188 (57.3) 208 (63.4)
120,000 NA NA NA 74 (22.6) 199 (60.7)
6001 to 7000
(1829 to 2134)
60,000 35 (10.7) 96 (29.3) 174 (53.0) 194 (59.1) NA
80,000 20 (6.1) 71 (21.6) 120 (36.6) 171 (52.1) 185 (56.4)
100,000 NA 31 (9.4) 79 (24.1) 178 (54.3) 195 (59.4)
120,000 NA NA NA 68 (20.7) 187 (57.0)
7001 to 8000
(2134 to 2438)
60,000 32 (9.8) 89 (27.1) 163 (49.7) 181 (55.2) NA
80,000 18 (5.5) 66 (20.1) 120 (36.6) 159 (48.5) 170 (51.8)
100,000 NA 29 (8.8) 73 (22.3) 167 (50.9) 182 (55.5)
120,000 NA NA NA 62 (18.9) 175 (53.3)
8001 to 9000
(2438 to 2743)
60,000 30 (9.1) 82 (25.0) 152 (46.3) 168 (51.2) NA
80,000 17 (5.2) 62 (18.9) 111 (33.8) 148 (45.1) 156 (47.5)
100,000 NA 27 (8.2) 67 (20.4) 157 (47.9) 170 (51.8)
120,000 NA NA NA 56 (17.1) 164 (50.0)
9001 to 10,000
(2743 to 3048)
60,000 27 (8.2) 76 (23.2) 142 (43.3) 156 (47.5) NA
80,000 15 (4.6) 57 (17.4) 103 (31.4) 137 (41.8) 142 (43.3)
100,000 NA 24 (7.3) 62 (18.9) 147 (44.8) 157 (47.9)
120,000 NA NA NA 51 (15.5) 153 (46.6)
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. Vent sizing for Canadian installations over 4500 ft. (1370 M) above sea level are subject to acceptance by the local authorities having jurisdiction.
4. Size both the combustion air and vent pipe independently, then use the larger size for both pipes.
5. Assume th e two 45_ elbows equal one 90_ elbow. Wide radius elbows are desirable and may be required in some cases.
6. Elbow and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
7. The minimum pipe length is 5 ft. (2 M) linear feet (meters) for all applications.
8. Use 3 ---in. (76 mm) diameter vent termination kit for installations requiring 4 ---in. (102 mm) diameter pipe.
59MN7A