Manifolded Combustion Air Option For Direct Vent Boiler Installations; Air Manifold Sizing; Combustion Air Manifold Option; Maintain Clearances And Placement Between The Air Manifold Inlet - Weil-McLain GV90+ Manual

GV90+ Series 2
Venting & air — general
Manifolded combustion air
option for DIRECT VENT
multiple boiler installations
1. Multiple GV90+ boilers can use a common com-
bustion air manifold.
a. The combustion air inlet must be located in a
sidewall (and the
b. See below for minimum cross sectional area of
combined air ducts.
c. Provide minimum clearance to adjacent vents
and grade/snow line as shown in Figure 37.
vents/air intake area clear of accumulating snow.
d. Provide minimum free area in duct (adjusted
for louver restriction) of
total boiler input.
e. If combustion air damper is used, wire to boil-
ers to prevent operation except after damper
has opened.
ONLY air piping can be combined.
this manual. Flue gas leakage and boiler
component damage can occur. Failure to
comply could result in severe personal
injury, death or substantial property
damage.

Air manifold sizing

1. See Figure 110, page 104 for minimum cross sec-
tional area of combined air ducts.
OR
2. CALCULATE required cross section (for area in
square inches):
a.
3. Example:
a. A multiple boiler system with (4)
boilers has a total input of 4 x 140 =
(560,000 Btuh).
b. The required duct cross sectional area is:
c.
The air manifold inlet of GV90+ boilers is part of direct vent connections. It is not classified as a forced air intake
with regard to spacing from adjacent boiler vents. To avoid recirculation, however, you must install the vent ter-
minations and air inlets with the clearances specified in Figure 38, page 31. The vent must be located following the
restrictions shown in Figure 41, page 35. The vent termination configuration can be any of the sidewall methods
(NOT VERTICAL) shown in this manual for direct vent or direct exhaust sidewall termination installations.
Part number 550-142-903/1016
-
GAS FIRED WATER BOILER
).
Keep
.
as described in
MBH
560
— Boiler Manual
(continued)
Combustion air manifold option (combined air inlet, but
individual vents) — must comply with Figure 41, page 35
Maintain clearances and placement between the air
manifold inlet and any appliance vent as shown below
.
31