Lennox EL180UHN Installation Instructions Manual page 17

Vent Connector Capacity Type B Double-Wall Vents with Type B Double-Wall Connectors
Height Lateral
H L
(feet) (feet)
1
6 2
3
1
8 2
3
1
10 2
3
1
15 2
3
1
20 2
3
1
30 2
3
Common Vent Capacity Type B Double-Wall Vents with Type B Double-Wall Connectors
Vent
Height
H
(feet)
FAN + FAN
6 92
8 101
10 110
15 125
20 136
30 152
Removal of the Furnace from Common Vent
In the event that an existing furnace is removed from a
venting system commonly run with separate gas applianc-
es, the venting system is likely to be too large to properly
vent the remaining attached appliances. Conduct the fol-
lowing test while each appliance is operating and the oth-
er appliances (which are not operating) remain connected
to the common venting system. If the venting system has
been installed improperly, you must correct the system as
indicated in the general venting requirements section.
Serving Two or More Category I Appliances
3 inch
Min Max
22 37
23 41
24 44
22 40
23 44
24 47
22 43
23 47
24 50
21 50
22 53
24 55
21 54
22 57
23 60
20 62
21 64
22 66
Serving Two or More Category I Appliances
4 inch
Appliance Input Rating in Thousands of Btu Per Hour
FAN + NAT FAN + FAN
81 140
90 155
97 169
112 195
123 215
138 244
TABLE 4
Vent and Connector Diameter - D (inches)
4 inch
Appliance Input Rating in Thousands of Btu Per Hour
Min Max
35 66
37 75
38 81
35 72
36 80
37 87
34 78
36 86
37 92
33 89
35 96
36 102
33 99
34 105
35 110
31 113
33 118
34 123
TABLE 5
Vent and Connector Diameter - D (inches)
5 inch
FAN + NAT FAN + FAN
116 204
129 224
141 243
164 283
183 314
210 361
CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each appliance
connected to the venting system being placed into operation
could result in carbon monoxide poisoning or death.
The following steps shall be followed for each appliance
connected to the venting system being placed into
operation, while all other appliances connected to the
venting system are not in operation:
Page 17
5 inch
Min Max
46 106
48 121
49 132
49 114
51 128
53 139
49 123
51 136
52 146
47 142
49 153
51 163
46 157
48 167
50 176
45 181
47 190
48 198
7 inch
FAN + NAT FAN + FAN
161 309
178 339
194 367
228 427
255 475
297 547
WARNING
6 inch
Min Max
58 164
60 183
62 199
64 176
66 195
67 210
65 189
67 206
69 220
64 220
66 235
68 248
62 246
64 259
66 271
60 288
62 299
64 309
7 inch
FAN + NAT
248
275
299
352
394
459