Install Instructions (Venting)

33
5.0 Manifold Combustion Air
SECTION V - MANIFOLD COMBUSTION AIR
5.1 Manifold Combustion Air Option for Multiple
Prestige Boilers
- Common combustion air manifold is restricted to hor-
izontal/side wall terminations only.
- The number of Prestige boilers connected to a com-
mon combustion air manifold system is limited to the
maximum boiler input shown in Table 9.
- The combustion air manifold must be constructed of
round solid core PVC pipe with minimum diameter
based on combined maximum boiler input capacity.
See Table 9.
Table 9: Common Combustion Air Piping
5.2 Equivalent Length of Combustion Air
Manifold
- The maximum equivalent length of the combustion
air manifold must not exceed the smallest maxi-
m
um equivalent length allowable for the boilers
connected to the manifold per Table 8 on page 10.
- Reduce the maximum equivalent length of com-
bustion air manifold as follows:
• The equivalent length of the transition piping
from the boiler to the manifold.
• 5 Feet for every 45º elbow
• 10 feet for every 90º elbow
Maximum Boiler Input
(MBH)
Minimum Diameter of
Combustion Air Piping
<400 4”
400-600 5”
601-800 6”
801-1600 8”
1601 -2000 10”