46
Table 16 – Maximum Equivalent Vent Length -- Ft.
NOTE: Maximum Equivalent Vent Length (MEVL) includes standard and concentric vent termination and does NOT include elbows.
Use Table 17 - Deductions from Maximum Equivalent Vent Length to determine allowable vent length for each application.
Unit Size
26,000
2
40,000
1
60,000
2
80,000
100,000
120,000
3
140,000
3
Altitude
(feet)
Pipe Dia. (in)
1 ½
2
1 ½
2
2 ½
1 ½
2
2 ½
3
1 ½
2
2 ½
3
4
2
2 ½
3
4
2 ½
3
4
2 ½
3
4
0--- 2000
70
200
40
155
185
20
100
175
200
15
55
130
175
200
20
80
175
200
10
75
185
5
65
155
2001--- 3000
65
190
35
150
175
95
165
185
10
49
125
165
185
15
75
165
185
70
175
N/A
60
140
3001--- 4000
60
175
30
135
160
16
90
155
175
115
155
175
155
175
5
65
165
120
4001--- 4500
55
160
25
130
155
15
85
150
170
44
110
150
165
10
70
170
N/A
60
160
50
110
4501--- 5000
125
145
80
145
165
145
160
65
150
165
45
100
5001--- 6000
50
145
20
120
130
75
140
155
41
100
135
150
140
155
155
35
80
6001--- 7000
45
135
15
110
120
13
70
130
145
N/A
38
90
125
140
60
135
145
50
140
30
65
7001--- 8000
40
120
10
100
110
10
65
120
135
36
120
125
N/A
55
125
135
46
130
25
45
8001--- 9000
35
110
90
95
5
60
115
125
33
80
110
115
50
115
125
43
120
15
30
9001--- 10000
30
95
5
80
85
N/A
55
105
115
30
75
100
105
45
100
115
39
115
10
15
Maximum Equivalent Vent Length --- Meters
Unit Size
26,000
2
40,000
1
60,000
2
80,000
100,000
120,000
3
140,000
3
Altitude
(meters)
Pipe Dia.
(mm)
38
51
38
51
64
38
51
64
76
38
51
64
76
102
51
64
76
102
64
76
102
64
76
102
0--- 610
21.3 60.9 12.1 47.2 56.3
6.0
30.4 53.3 60.9
4.5
16.7 39.6 53.3 60.9
6.0
24.3 53.3 60.9
3.0
22.8 56.3
1.5
19.8 47.2
611--- 914
19.8 57.9 10.6 45.7 53.3
28.9 50.2 56.3
3.0
14.9
38.1 50.2 56.3
4.5
22.8
50.2 56.3
21.3 53.3
NA
18.2
42.6
915--- 1219
18.2 53.3
9.1
41.1 48.7
4.8
27.4 47.2 53.3
35.0 47.2 53.3
47.2
53.3
1.5
19.8 50.2
36.5
1220--- 1370
16.7 48.7
7.6
39.6 47.2
4.5
25.9 45.7 51.8
13.4 33.5
45.7 50.2
3.0
21.3
51.8
NA
18.2
48.7
15.2 33.5
1371--- 1524
38.1 44.1
24.3 44.1 50.2
44.1 48.7
19.8
45.7 50.2
13.7 30.4
1525--- 1829
15.2 44.1
6.0
36.5 39.6
22.8 42.6 47.2
12.4 30.4 41.1 45.7
42.6 47.2
47.2
10.6 24.3
1830--- 2134
13.7 41.1
4.5
33.5 36.5
3.9
21.3 39.6 44.1
NA
11.5
27.4
38.1 42.6
18.2 41.1 44.1
15.2 42.6
9.1
19.8
2135--- 2438
12.1 36.5
3.0
30.4 33.5
3.0
19.8 36.5 41.1
10.9
36.5 38.1
NA
16.7 38.1 41.1
14.0 39.6
7.6
13.7
2439--- 2743
10.6 33.5
27.4 28.9
1.5
18.2 35.0 38.1
10.0 24.3 33.5 35.0
15.2 35.0 38.1
13.1 36.5
4.5
9.1
2744--- 3048
9.1
28.9
1.5
24.3 25.9
NA
16.7 32.0 35.0
9.1
22.8 30.4 32.0
13.7 30.4 35.0
11.8 35.0
3.0
4.5
NOTES
:
1. 40K Inducer Outlet Restrictor disk (P/N 337683---401; 1.25---in. (32 mm) Dia.) shipped in the loose parts bag or available through Replacement Components
required under 10---ft. (3 M) TEVL in all orientations. Required for installations from 0 --- 2000 ft. (0 to 610 M) above sea level. Failure to use an outlet
restrictor may result in flame disturbances or flame sense lock---out.
2. 26K (shipped in the loose parts bag) & 60K Inducer Outlet Restrictor disk (P/N 337683---401; 1.25---in. (32 mm) Dia.) 337683---401available through
Replacement Components required for no greater than 5---ft. (1.5 M) TEVL in downflow and horizontal orientations only. Required for installations from 0 ---
2000 ft. (0 to 610 M) above sea level.
3. 120K & 140K Inducer Outlet Restrictor disk (P/N
337683---402
; 1.50---in. (38 mm) Dia.) available through
Replacement Components
required for no greater
than 5---ft. (1.5 M) TEVL in downflow and horizontal orientations only. Required for installations from 0 --- 2000 ft. (0 to 610 M) above sea level.
Long
Medium
Mitered
Concentric
Standard 2-in., 3-in., or
optional 4-in. termination.
ELBOW CONFIGURATIONS
VENT TERMINAL CONFIGURATIONS
A13110
Table 17 – Deductions from Maximum Equivalent Vent Length -- Ft. (M)
Pipe Diameter (in):
1-1/2
2
2-1/2
3
4
Mitered 90º Elbow
8
(2.4)
8
(2.4)
8
(2.4)
8
(2.4)
8
(2.4)
Medium Radius 90º Elbow
5
(1.5)
5
(1.5)
5
(1.5)
5
(1.5)
5
(1.5)
Long Radius 90º Elbow
3
(0.9)
3
(0.9)
3
(0.9)
3
(0.9)
3
(0.9)
Mitered 45º Elbow
4
(1.2)
4
(1.2)
4
(1.2)
4
(1.2)
4
(1.2)
Medium Radius 45º Elbow
2.5
(0.8)
2.5
(0.8)
2.5
(0.8)
2.5
(0.8)
2.5
(0.8)
Long Radius 45º Elbow
1.5
(0.5)
1.5
(0.5)
1.5
(0.5)
1.5
(0.5)
1.5
(0.5)
Tee
16
(4.9)
16
(4.9)
16
(4.9)
16
(4.9)
16
(4.9)
Concentric Vent Termination
NA
0
(0.0)
NA
0
(0.0)
NA
Standard Vent Termination
0
(0.0)
0
(0.0)
0
(0.0)
0
(0.0)
0
(0.0)
NOTES
:
1. Use only the smallest diameter pipe possible for venting. Over---sizing may cause flame disturbance or excessive vent terminal icing or freeze---up.
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 the 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.
