Page 15
TABLE 8
CAPACITY OF TYPE B DOUBLE-WALL VENTS WITH SINGLE-WALL METAL CONNECTORS
SERVING TWO OR MORE CATEGORY I APPLIANCES COMMON VENT CAPACITY
Common Vent Diameter - D (inches)
Vent
Height
4 Inch
5 Inch
6 Inch
7 Inch
Height
H (feet)
Appliance Input Rating in Thousands of Btu Per Hour
H (feet)
FAN + FAN
FAN + NAT
FAN + FAN
FAN + NAT
FAN + FAN
FAN + NAT
FAN + FAN
FAN + NAT
6
89
78
136
113
200
158
304
244
8
98
87
151
126
218
173
331
269
10
106
94
163
137
237
189
357
292
15
121
108
189
159
275
221
416
343
20
131
118
208
177
305
247
463
383
30
145
132
236
202
350
286
533
446
Removal of the Furnace from the Common Vent
In the event that an existing furnace is removed from a
venting system commonly run with separate gas ap
pliances, the venting system is likely to be too large to
properly vent the remaining attached appliances. The
following test should be conducted while each appliance
is in operation and the other appliances not in operation
remain connected to the common venting system. If the
venting system has been installed improperly, the sys
tem must be corrected as indicated in the general vent
ing requirements section.
1 - Seal any unused openings in the common venting
system.
2 - Visually inspect the venting system for proper size
and horizontal pitch and determine there is no block
age or restriction, leakage, corrosion and other defi
ciencies which could cause an unsafe condition.
3 - To the extent that it is practical, close all building
doors and windows and all doors between the space
in which the appliances remaining connected to the
common venting system are located and other
spaces of the building. Turn on clothes dryers and
any appliances not connected to the common vent
ing system. Turn on any exhaust fans, such as range
hoods and bathroom exhausts, so they will operate
at maximum speed. Do not operate a summer ex
haust fan. Close fireplace dampers.
4 - Following the lighting instruction, place the appliance
being inspected in operation. Adjust thermostat so
appliance will operate continuously.
5 - Test for spillage of flue gases at the draft hood relief
opening after 5 minutes of main burner operation.
Use the flame of a match or candle, or smoke from a
cigarette, cigar or pipe.
6 - After determining that each appliance remaining
connected to the common venting system properly
vents when tested as indicated in step 3, return
doors, windows, exhaust fans, fireplace dampers
and any other gasburning appliance to their pre
vious condition of use.
7 - If improper venting is observed during any of the
above tests, the common venting system must be
corrected. The common venting system should be
resized to approach the minimum size as deter
mined by using the appropriate tables in appendix G
in the current standards of the National Fuel Gas
Code ANSI Z223.1.
Horizontal Venting
SIDE WALL VENTING KIT WIRING
C
L1
L2
120VAC
M
L1
M
N
T1 T2 T3
W R
Y
G
W
G
R
Y
24 VAC
THERMOSTAT
THERMOSTAT CONNECTIONS
TERMINAL IN FURNACE
JUNCTION BOX
RELAY
CK-43 CONTROL BOX
PRESSURE
SWITCH
SWG
POWER
VENTER
MOTOR
FIGURE 13
T
FIELD INSTALLED WIRING
FACTORY INSTALLED WIRING
NO
2
1
3
5
4
This furnace is design certified by the American Gas As
sociation for horizontal venting through an outside wall
only with the use of a Field Controls Company Model
SWG-4L side wall venting kit available from Lennox Deal
er Service Center. No other Field brand venting kit or any
other manufacturer's venting kit is acceptable. Horizontal
venting of this furnace without the use of the above stated
kit is prohibited. See figure 13 for field wiring of side wall
horizontal venting kit.
When horizontally vented, the minimum clearance for ter
mination from electric meters, gas meters, regulators,
and relief equipment is 4 feet (1.2m).