Specification

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Venting
Size the SWG or ComboVent venter based on the input firing rate of the appliance. If the power venter is being
used to vent multiple appliances, add the input firing rates for each appliance and use that total to size the venter.
Knowing the total input BTU/hr. for gas, or GPH for oil, the venter can be sized from Table 1. Select the venter
rated closest to the total input BTU or GPH for installation. If the input of the appliance is higher than the maximum
allowable for that size SWG or CV, move to the next larger size SWG or CV.
Do not select a venter with a maximum BTU/hr. or GPH lower than the appliance. The equivalent feet of vent
pipe for the installation must be calculated. Based on the vent pipe diameter to be used, compare the calculated
equivalent feet of vent pipe with the maximum equivalent feet allowable for the venter (See Table 1). If the
calculated equivalent feet is greater than that allowed for the venter, increase the diameter of the vent pipe to be
used and refer to the table or use the next larger size SWG or CV venter.
Note: In Table 1, the maximum equivalent footage allowable for the vent pipe is given for two points, the maximum BTU/hr. venting
capacity and at 60% of the maximum. This allows for estimating values between the two given points.
Sizing The Venter (Use Maximum BTU or GPH Input)
MODEL
MAX* OIL
GPH INPUT
100psi
MAX* OIL
GPH INPUT
140psi
MAX** GAS
BTU/hr.
INPUT
Maximum Equivalent Feet of Vent Pipe
VENT
PIPE SIZE
AT MAX
BTU/hr. INPUT
AT 60% OF MAX
BTU/hr. INPUT
SWG-3
N/A N/A 70,000
21 80 3"
50 100 4"
SWG-4HD, 4HDs, CV-4
1.10 .90 170,000
35 100 4"
65 100 5"
100 100 6"
100 100 7"
SWG-5, 5s, CV-5
1.85 1.55 290,000
16 44 4"
51 100 5"
95 100 6"
100 100 7"
SWG-6, 6s
2.65 2.25 416,000
28 78 5"
68 100 6"
100 100 7"
SWG-8
4.75 4.0 740,000
26 72 7"
51 100 8"
70 100 9"
SWG-10
9 7.5 1,300,000
10 100 8"
30 100 10"
75 100 12"
SWG-12
13.5 11.5 1,900,000
16 100 10"
40 100 12"
86 100 14"
* Oil: Select venter according to the actual rated maximum GPH input. SWG GPH ratings at 100 psi. Do not exceed maximum oil GPH input.
** Gas: Do not exceed maximum BTU/hr. input rating. For multiple venting system applications add the input for each appliance. Category I gas-
fired draft induced systems require an SWG-4HD or larger. Category III gas-fired draft induced systems require an SWG-5 or larger. Unit sizing
may vary depending on specific application. Consult your dealer or factory representative for the proper sizing for your particular application.
Table 1
NOTE: Control Kits are required for operation of the SWG. Stainless steel recommended for oil applications.
Sizing The Venter
SWG/CV Power Venter