AERCO BMK 2.0 LN Natural Gas (SN G-11-1861 and above) - Manual (Page 30)

Chapter 2
Benchmark 2.0LN Low NOx Boiler
GF-123
Installation Installation, Operation and Maintenance Manual OMM-0046_0E
Page 30 of 170 AERCO International Inc.● 100 Oritani Dr. ● Blauvelt, NY 10913. ● Ph: 800-526-0288 PR1 08/20/12
Selkirk Corporation, Heatfab Division ( www.heat-fab.com ),130 Industrial Blvd., Turners Falls,
MA 01376
Phone: 1-800-772-0739
2.12 COMBUSTION AIR
The AERCO Benchmark Venting and Combustion Air Guide, GF-2050 MUST be consulted
before any flue or combustion supply air venting is designed or implemented. Combustion air
supply is a direct requirement of ANSI 223.1, NFPA-54, CSA B149.1 and local codes. These
codes should be consulted before a permanent design is determined.
The combustion air must be free of chlorine, halogenated hydrocarbons, or other chemicals that
can become hazardous when used in gas-fired equipment. Common sources of these
compounds are swimming pools, degreasing compounds, plastic processing and refrigerants.
Whenever the environment contains these types of chemicals, combustion air must be supplied
from a clean area outdoors for the protection and longevity of the equipment.
The AERCO Benchmark 2.0LN Boiler is UL listed for 100% sealed combustion. It can also be
installed using room air, provided there is an adequate supply. (See para. 2.13.3 for more
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.
2.12.1 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.
2.12.2 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.
2.12.3 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 6 inch diameter connection at the
unit.
2.12.4 Temporary Combustion Air Filtering During Construction
When the Benchmark 2.0LN 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