AERCO BMK 3.0 LN Natural Gas July 2011 - Manual (Page 24)

INSTALLATION
2-12
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, consult
the AERCO Benchmark Venting and
Combustion 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.
For Canada installations, refer to the
requirements specified in CSA B149.1-10, 8.4.1
and 8.4.3.
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 3.0 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.
2.13.4 Temporary Combustion Air
Filtering During Construction
When the AERCO Benchmark 3.0 Boiler is used
to provide heat temporarily during ongoing
building construction, accumulated drywall dust,
sawdust and similar particles can accumulate in
the unit’s combustion air intake filter and block
combustion air flow. In these situations, AERCO
recommends that a disposable air intake filter be
installed, temporarily, above the boiler
combustion air inlet.
AERCO recommends that the temporary air filter
be cut from a McMaster-Carr part no. 2122K315
Polyester Air Filter Roll Tackfield, 1/2” thick, 16”
wide, or equivalent. Cover the Benchmark 3.0
air inlet with the blue side of the filter material
facing outward to hold the dust on the outside
surface. Maximize the surface area of the filter
covering the 8" diameter opening by creating a
dome out of the filter material.
During construction, check the filter for dust
accumulation and replace it when the
accumulation becomes noticeable.