Burnham CHG225 - Manual (Page 8)


VI Venting
warNINg
Failure to vent this boiler in accordance with these instructions could result in unreliable boiler operation,
severe damage to the boiler or property, or unsafe operation:
• Do not attempt to vent this boiler with galvanized, PVC, or any other vent system not listed in Table 4.
• Do not attempt to mix components from different approved vent systems.
• Do not obtain combustion air from within the building.
• Do not install a barometric damper or drafthood on this boiler.
• Do not attempt to use the vent system for this boiler with any other appliance.
• Moisture and ice may form on the surfaces around the vent termination. To prevent deterioration,
surfaces should be in good repair (sealed, painted, etc.)
A. Vent System Design
There are two basic ways to vent the CHG boiler:
• Horizontal (“side wall”) Venting - Vent system exits the building through an outside wall. Combustion air is
obtained through a separate pipe from outside.
• Vertical Venting - Vent system exits the building through a roof. Combustion air is obtained through a separate
pipe from outside.
A description of each of these venting options is listed in Tables 6.2a and 6.2b. For clarity, these vent options are
numbered from 1 to 7. One of the vent option columns in Table 6.2 must match the planned vent and air intake
system exactly. In addition, observe the following guidelines:
1) Approved vent systems - Use only one of the approved vent systems shown in Table 4. These systems are made of a
special stainless steel alloy (AL29-4C) for protection against corrosive flue gas condensate. They are also designed to
provide a gas tight seal at all joints and seams so that flue gas does not enter the building. Each approved vent system
has a unique method for installation - do not attempt to mix components from different vent systems.
2) Maximum Vent and Air Intake Lengths - The maximum length of the vent air intake piping depends upon the vent
option selected and the boiler size. See Table 6.2 for the maximum vent length. In addition to the maximum length of
piping shown in Table 6.2, the following fittings may also be used:
• Horizontal Vent Systems: One 90 deg. elbow
• Horizontal Air Intake Systems: One 90 deg. elbow
• Vertical Vent Systems: Two 90 deg. elbows
• Vertical Air Intake Systems: Two 90 deg. elbows
If additional elbows are desired, the maximum allowable vent length must be reduced by the amount shown in Table
6.6 for each additional elbow used. Termination fittings are not counted when counting additional elbows.
Example:
A 3” vent system is planned for a horizontally vented CHG150 which has the following components:
2 ft vertical pipe
1 90 elbow
5 ft horizontal pipe
1 90 elbow
3 ft horizontal pipe
1 45 elbow
4 ft horizontal pipe
1 termination elbow