Weil-McLain ULTRA299-S4 Manual page 59

S 4
®
ERIES GAS
Multiple boiler installations
Part number 550-100-400/0717
-
FIRED WATER BOILER
Manifolded combustion air option
1. Multiple Ultra boilers can use a common combustion air manifold.
a. See Figure 139, page 138 for minimum cross sectional area of
b. Provide minimum clearance to adjacent vents and grade/snow line
c. Provide minimum free area in duct (adjusted for louver restriction)
d. If combustion air damper is used, wire to boilers to prevent opera-
— Boiler Manual
(continued)
combined air ducts.
as shown in Figure 59 .
of
tion except after damper has opened.
ONLY air piping can be combined. DO NOT use combined
vent piping. Flue gas leakage and boiler component damage
can occur. Failure to comply could result in severe personal
injury, death or substantial property damage.
Manifolded combustion air option
DO NOT use common venting — the manifold option is
only for combustion air — all vent pipes must be routed and
terminated individually as described in this manual.
See Figure 139, page 138 for minimum cross sectional area
of combined air ducts.
OR
Calculate required cross section (for area in square inches):
Example: A multiple boiler system with (6) Ultra-155 boilers
has a total input of 6 x 155 =
required duct cross sectional area is:
total boiler input.
MBH (930,000 Btuh). The
59