Ultra Boiler Manual

Part number 550-100-440/0122
59
  
ADVANCED INSTALLATION
Figure 59 Manifolded combustion air option
U3160
Air Vent
12" min
Grade or
snow line
Minimum 3 feet below any vent termination within 10 feet
Air VentAir Vent
Air duct
 (continued)

1. Multiple Ultra boilers can use a common combustion air manifold.
a. See Figure 139,page138 for minimum cross sectional area of
combined air ducts.
b. Provide minimum clearance to adjacent vents and grade/snow line
as shown in Figure59.
c. Provide minimum free area in duct (adjusted for louver restriction)
of
1 square inch per 2,000 Btuh total boiler input.
d. If combustion air damper is used, wire to boilers to prevent opera-
tion except aer 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.
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):
MIN. AREA = TOTAL MBH INPUT DIVIDED BY 2
Example: A multiple boiler system with (6) Ultra-155 boilers
has a total input of 6 x 155 = 930 MBH (930,000 Btuh). e
required duct cross sectional area is:
MIN. AREA = 930 DIVIDED BY 2 = 465 sq. inches