AERCO BMK 2.0 LN Natural Gas 2008 - Manual (Page 20)

INSTALLATION
2-10
information concerning sealed combustion air).
If the sealed combustion air option is not being
used, an inlet screen will be attached at the air
inlet on the top of the unit
The more common methods of supplying
combustion air are outlined below. For more
information concerning combustion air, refer to
the AERCO Benchmark Venting and Combus-
tion Air Guide, GF-2050.
2.13.1 Combustion Air From Outside the
Building
Air supplied from outside the building must be
provided through two permanent openings. Each
opening must have a free area of not less than
one square inch for each 4000 BTU/H boiler
input. The free area must take into account
restrictions such as louvers and bird screens.
2.13.2 Combustion Air From Inside the
Building
When combustion air is provided from within the
building, it must be supplied through two
permanent openings in an interior wall. Each
opening must have a free area of not less than
one square inch per 1000 BTU/H of total boiler
input. The free area must take into account any
restrictions such as louvers.
2.13.3 Sealed Combustion
The AERCO Benchmark 2.0LN Boiler is UL
listed for 100%-sealed combustion. For sealed
combustion installations, the screen on the air
inlet duct of the unit must be removed. The inlet
air ductwork must then be attached directly to
the unit’s air inlet.
In a sealed combustion air application, the
combustion air ducting pressure losses must be
taken into account when calculating the total
maximum allowable venting run. See the
AERCO Benchmark Venting and Combustion
Air Guide, GF-2050. When using the boiler in a
sealed combustion air configuration, each unit
must have a minimum 8 inch diameter
connection at the unit.