INSTALLATION INSTRUCTIONS
Gas Furnace: (F/G)MAC
46
440 01 4201 01
Specifications subject to change without notice.
Table 12
MAXIMUM EQUIVALENT VENT LENTH
- Feet (Meters)
Note:
Maximum Equivalent Vent Length (MEVL) does NOT include elbows or terminations
Use
Table 14
−
DEDUCTIONS FROM MEVL to determine allowable vent length for each application.
Altitude
FT (M)
Unit Size
BTU/Hr
DIRECT VENT (2-PIPE) AND VENTILATED COMBUSTION AIR
Vent Pipe Diameter (in.)
1-1/2
2
2-1/2
3
4
0 to 2000
(0 to 610)
60,000
55
(16.8)
135
(41.1)
235
(71.6)
265
(80.8)
N/A
80,000
35
(10.7)
130
(39.6)
175
(53.3)
235
(71.6)
265
(80.8)
100,000
N/A
50
(15.2)
110
(33.5)
235
(71.6)
265
(80.8)
120,000
N/A
N/A
15
(4.6)
100
(30.5)
250
(76.2)
2001 to 3000
(610 to 914)
60,000
45
(13.7)
127
(38.7)
222
(67.7)
250
(76.2)
N/A
80,000
30
(9.1)
90
(27.4)
165
(50.3)
222
(67.7)
249
(75.9)
100,000
N/A
40
(12.2)
104
(31.7)
223
(68.0)
250
(76.2)
120,000
N/A
N/A
11
(3.4)
93
(28.3)
237
(72.2)
3001 to 4000
(914 to 1219)
60,000
40
(12.2)
119
(36.3)
210
(64.0)
235
(71.6)
N/A
80,000
25
(7.6)
85
(25.9)
155
(47.2)
210
(64.0)
232
(70.7)
100,000
N/A
40
(12.2)
98
(29.9)
211
(64.3)
236
(71.9)
120,000
N/A
N/A
8
(2.4)
86
(26.2)
224
(68.3)
4001 to 4500
(1219 to 1370)
60,000
35
(10.7)
115
(35.1)
204
(62.2)
228
(69.5)
N/A
80,000
23
(7.0)
85
(25.9)
150
(45.7)
202
(61.6)
224
(68.3)
100,000
N/A
40
(12.2)
94
(28.7)
205
(62.5)
229
(69.8)
120,000
N/A
N/A
N/A
83
(25.3)
217
(66.1)
See notes at end of Venting Tables.
See
Table 13
for altitudes over 4500 ft (1370m).
Table 13
MAXIMUM EQUIVALENT VENT LENTH
- Feet (Meters)
Note:
Maximum Equivalent Vent Length (MEVL) does NOT include elbows or terminations.
Use DEDUCTIONS FROM MEVL
−
Table 14
to determine allowable vent length for each application.
Note:
Vent sizing for Canadian installations over 4500 ft. (1370 M) above sea level are subject to acceptance
by the local authorities having jurisdiction.
Altitude
FT (M)
Unit Size
DIRECT VENT (2-PIPE) AND VENTILATED COMBUSTION AIR
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)
N/A
80,000
23
(7.0)
85
(25.9)
146
(44.5)
195
(59.4)
216
(65.8)
100,000
N/A
40
(12.2)
91
(27.7)
200
(61.0)
222
(67.7)
120,000
N/A
N/A
N/A
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)
N/A
80,000
22
(6.7)
76
(23.2)
137
(41.8)
183
(55.8)
200
(61.0)
100,000
N/A
33
(10.1)
85
(25.9)
188
(57.3)
208
(63.4)
120,000
N/A
N/A
N/A
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)
N/A
80,000
20
(6.1)
71
(21.6)
120
(36.6)
171
(52.1)
185
(56.4)
100,000
N/A
31
(9.4)
79
(24.1)
178
(54.3)
195
(59.4)
120,000
N/A
N/A
N/A
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)
N/A
80,000
18
(5.5)
66
(20.1)
120
(36.6)
159
(48.5)
170
(51.8)
100,000
N/A
29
(8.8)
73
(22.3)
167
(50.9)
182
(55.5)
120,000
N/A
N/A
N/A
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)
N/A
80,000
17
(5.2)
62
(18.9)
111
(33.8)
148
(45.1)
156
(47.5)
100,000
N/A
27
(8.2)
67
(20.4)
157
(47.9)
170
(51.8)
120,000
N/A
N/A
N/A
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)
N/A
80,000
15
(4.6)
57
(17.4)
103
(31.4)
137
(41.8)
142
(43.3)
100,000
N/A
24
(7.3)
62
(18.9)
147
(44.8)
157
(47.9)
120,000
N/A
N/A
N/A
51
(15.5)
153
(46.6)
NOTES:
A. 3- and 4-inch vent pipe systems require long radius elbows.
B. Vent sizing for Canadian installations over 4500 ft. (1370 M) above sea level are subject to acceptance by the local authorities having jurisdiction.
C. N/A - Not Allowed; pressure switch will not close, or flame disturbance may result..
D. Do not use pipe size greater than those specified in table or incomplete combustion, flame disturbance, or flame sense lockout may occur.
E. Size both the combustion-air and vent pipe independently, then use the larger diameter for both pipes.
F. Assume two 45
°
elbows equal one 90
°
elbow. Wide radius elbows are desirable and may be required in some cases.
G. Elbows and pipe sections within the furnace casing and at the vent termination should not be included in vent length or elbow count.
H. The minimum pipe length is 5 ft (1.5 M) for all applications.
I. Use 3-in. (76 mm) diameter concentric vent termination kit for installations requiring 4-in (102 mm) diameter pipe.
