Part number 550-101-232/0703
13
GAS
-
FIRED
WATER
BOILER
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Installation Manual — Multiple-boiler Systems
Figure 12
Manifolding combution air piping
Combustion air & vent piping installation
Vent piping
1. Each boiler requires an individual vent pipe, in-
stalled and terminated per the Ultra Boiler Manual
and Ultra Boiler Venting Suppments.
2. The vent pipes of multiple boilers must terminate on
the same side of the building as their air inlet piping,
and per all requirements of the Ultra Boiler Manual
and Vent Supplements.
Combustion air piping
1. Provide combustion air piping to each boiler, fol-
lowing all requirements for installation and termi-
nation per the Ultra Boiler Manual and Ultra Boiler
Venting Supplements.
2. Combustion air piping can be supplied from a
common combustion air manifold, installed and
terminated as shown in Figure 12, below.
Combustion air manifolds
1. When combustion air supplied from a common air
manifold pipe as in Figure 12, size the common air
duct and louver free area from the minimum free
area given in Figure 1, pages 4 and 5.
2. All joints must be sealed.
3. The air inlet must be located:
•
at least 3 feet below any vent located within 10
feet.
•
the louver bottom must be 12 inches above grade
or above the snow line.
4. Compensate for louver blockage when calculating
free air openings. Refer to manufacturer’s instruc-
tions for size. If unknown use:
a. Wood louvers — 20-25% free area.
b. Metal louvers or grilles — 60-75% free area.
5. Lock open louvers or interlock with boiler controls
to open automatically with boiler operation.
