Filter
Top Products
TABLE 4—MAXIMUM ALLOWABLE VENT PIPE LENGTH (FT)
ALTITUDE (FT) UNIT SIZE
VENT PIPE
DIAMETER (IN.)
NUMBER OF 90° ELBOWS
1 23456
0 to 2000
024040
036040
1 5 NA NA NA NA NA
1-1/2 70 70 65 60 60 55
2 70 7070707070
024060
036060
048060
1-1/2 20 15 10 5 NA NA
2 70 7070707070
036080
048080
060080
1-1/2 10 NA NA NA NA NA
2 55 5035303020
2-1/2 70 70 70 70 70 70
048100
060100
2 5 NA NA NA NA NA
2-1/2 40 30 20 20 10 NA
3 70 7070707070
060120
2-1/2 10 NA NA NA NA NA
3* 70 70 70 70 70 70
ALTITUDE (FT) UNIT SIZE
VENT PIPE
DIAMETER (IN.)
NUMBER OF 90° ELBOWS
1 23456
2001 to 3000
024040
036040
1-1/2 67 62 57 52 52 47
2 70 7070707070
024060
036060
048060
1-1/2 17 12 7 NA NA NA
2 70 6766616161
036080
048080
060080
2 49 4430252515
2-1/2 70 70 70 70 70 70
048100
060100
2-1/2 35 26 16 16 6 NA
3 70 7070706661
060120 3* 63 62 62 61 61 61
ALTITUDE (FT) UNIT SIZE
VENT PIPE
DIAMETER (IN.)
NUMBER OF 90° ELBOWS
1 23456
3001 to 4000
024040
036040
1-1/2 64 59 54 49 48 43
2 70 7070707070
024060
036060
048060
1-1/2 16 11 6 NA NA NA
2 68 6362575756
036080
048080
060080
2 46 4128232213
2-1/2 70 70 70 70 70 70
048100
060100
2-1/2 33 24 15 14 5 NA
3 70 7070666156
060120 3* 59 59 58 57 57 56
ALTITUDE (FT) UNIT SIZE
VENT PIPE
DIAMETER (IN.)
NUMBER OF 90° ELBOWS
1 23456
4001 to 5000†
024040
036040
1-1/2 60 55 50 45 44 39
2 70 7070707070
024060
036060
048060
1-1/2 15 10 5 NA NA NA
2 64 5958535252
036080
048080
060080
2 44 3926212011
2-1/2 70 70 70 70 70 70
048100
060100
2-1/2 31 22 13 12 NA NA
3 70 7067625752
060120 3* 56 55 54 53 52 52
* Wide radius elbow.
† Vent sizing for Canadian installations over 4500 ft (1370 m) above sea level are subject to acceptance by the local authorities having jurisdiction.
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. Assume two 45° elbows equal one 90° elbow. Long radius elbows are desirable and may be required in some cases.
3. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
4. The minimum pipe length is 5 ft for all applications.
—25—