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Table 7 — Maximum Allowable Pipe Length -- Ft (M) (Continued)
ALTITUDE
UNIT SIZE
(BTUH)
Direct Vent (2--Pipe Only)
NUMBER OF 90_ ELBOWS
Termination
Type
Pipe Dia
In. (mm)*
1 2 3 4 5 6
6001 to 7000
(1829 to 2134)‡
60,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 35 (10.7) 30 (9.1) 25 (7.6) 20 (6.1) 15 (4.6) 10 (3.0)
2 (51) 70 (21.3) 70 (21.3) 68 (20.7) 67 (20.4) 66 (20.1) 64 (19.5)
80,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 20 (6.1) 15 (4.6) 10 (3.0) 5 (1.5) NA NA
2 (51) 70 (21.3) 70 (21.3) 68 (20.7) 67 (20.4)
62
(18.9)
57 (17.4)
100,000
2 Pipe or 2 ---In. (51)
Concentric
2 (51) 31(9.4) 26 (7.9) 21 (6.4) 16 (4.9) 11 (3.4) 6 (1.8)
2---1/2 (64) 70 (21.3) 70 (21.3) 68 (20.7) 67(20.4) 66 (20.1) 64 (19.5)
120,000
2 Pipe or 3 ---In. (76)
Concentric
3 (76) one disk† 49 (14.9) 48 (14.6) 47(14.3) 45 (13.7) 44 (13.4) 43 (13.1)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Pipe Dia
In. (mm)*
NUMBER OF 90_ ELBOWS
1 2 3 4 5 6
7001 to 8000
(2134 to 2438)‡
60,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 32 (9.8) 27 (8.2) 22 (6.7) 17 (5.2) 12 (3.7) 7 (2.1)
2 (51) 66 (20.1) 65 (19.8) 63 (19.2) 62 (18.9) 60 (18.3) 59 (18.0)
80,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 18 (5.5) 13 (4.0) 8 (2.4) NA NA NA
2 (51) 66 (20.1) 65 (19.8) 63 (19.2) 62 (18.9) 57 (17.4) 52 (15.8)
100,000
2 Pipe or 2 ---In. (51)
Concentric
2 (51) 29(8.8) 24 (7.3) 19 (5.8) 14 (4.3) 9 (2.7) NA
2---1/2 (64) 66 (20.1) 65 (19.8) 63 (19.2) 62(18.9) 60 (18.3) 59 (18.0)
120,000
2 Pipe or 3 ---In. (76)
Concentric
3 (76) one disk† 46 (14.0) 44 (13.4) 43(13.1) 41 (12.5) 40 (12.2) 38 (11.6)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Pipe Dia
In. (mm)*
NUMBER OF 90_ ELBOWS
1 2 3 4 5 6
8001 to 9000
(2438 to 2743)‡
60,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 30 (9.1) 25 (7.6) 20 (6.1) 15 (4.6) 10 (3.0) 5 (1.5)
2 (51) 62 (18.9) 60 (17.8) 58 (17.7) 56 (17.1) 55 (16.8) 53 (16.2)
80,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 17 (5.2) 12 (3.1) 7 (2.1) NA NA NA
2 (51) 62 (18.9) 60 (18.3) 58 (17.7) 56 (17.1) 51 (15.5) 46 (14.0)
100,000
2 Pipe or 2 ---In. (51)
Concentric
2 (51) 27(8.2) 22 (6.7) 17 (5.2) 12 (3.7) 7 (2.1) NA
2---1/2 (64) 62 (18.9) 60 (18.3) 58 (17.7) 56(17.1) 55 (16.8) 53 (16.2)
120,000
2 Pipe or 3 ---In. (76)
Concentric
3 (76) one disk† 43 (13.1) 41 (12.5) 39/11.9) 37 (11.3) 35 (10.7) 34 (10.4)
ALTITUDE
UNIT SIZE
(BTUH)
Termination
Type
Pipe Dia
In. (mm)*
NUMBER OF 90_ ELBOWS
1 2 3 4 5 6
9001 to 10000
(2743 to 3048)‡
60,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 27 (8.2) 22 (6.7) 17 (5.2) 12 (3.7) 7 (2.1) NA
2 (51) 57 (17.4) 55 (16.8) 53 (16.2) 51 (15.5) 49 (14.9) 47 (14.3)
80,000
2 Pipe or 2 ---In. (51)
Concentric
1---1/2 (38) 15 (4.6) 10 (3.0) 5 (1.5) NA NA NA
2 (51) 57 (17.4) 55 (16.8) 53 (16.2) 51 (15.5) 46 (14.0) 41 (12.5)
100,000
2 Pipe or 2 ---In. (51)
Concentric
2 (51) 24(7.3) 19 (5.8) 14 (4.3) 9 ( 2.7) NA NA
2---1/2 (64) 57 (17.4 55 (16.8) 53 (16.2) 51(15.5) 49 (14.9) 47 (14.3)
120,000
2 Pipe or 3 ---In. (76)
Concentric
3 (76) one disk† 39 (11.9) 37 (11.3) 35(10.7) 33 (10.1) 31 (9.5) 29 ( 8.8)
* Disk usage---Unless otherwise stated, use perforated disk assembly (factory---supplied in loose parts bag).
{ Wide radius elbow.
} Vent sizing for Canadian install a tions over 4500 f t. (1370M) above sea level are subject to acceptance by the local a uthorities having jur isdiction.
NA---Not Allowed; pressure switch will not make.
NOTES:
1. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
2. Si zeboth thecombustion---air a ndventpipe independently,determine thesmallest diameterallowedbythe tablefor eachpipe, thenusethelarger diameterforbothpipes.
3. Assume two 45_ elbows equal one 90_ elbow . Long radius elbows are desirable and may be required in some cases.
4. Elbowsand pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
5. The minimum pipe length is 5 ft. (1.5M) for all applications.
355CAV