Combustion Air; Ducted Combustion Air - Watts Aerco BENCHMARK 750 User Manual

Benchmark 750 – 1000 Boiler User Manual - INTERNATIONAL

2.12 COMBUSTION AIR

The AERCO Benchmark Boiler Venting and Combustion Air Guide, GF-2055 MUST be
consulted before any flue or inlet air venting is designed or installed. 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 and
warranty validation.
For combustion air supply from ducting, see section 2.12 below and consult the AERCO GF-
2055, Gas Fired Venting and Combustion Air Guide.
Air must be supplied to the unit(s) through two permanent openings. These two openings must
have a free area of not less than one square inch (6.5 cm
input for each unit. The free area must take into account restrictions such as louvers and bird
screens.

2.13 DUCTED COMBUSTION AIR

For ducted combustion air installations, the air ductwork must then be attached directly to the air
inlet connection on the sheet metal enclosure.
In a ducted 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-2055. When using the unit in a ducted
combustion air configuration, the minimum diameter connection at the unit is:
•
BMK 750 – 6 inch (15.2 cm) diameter connection
•
BMK 1000 – 8 inch (20.3 cm) diameter connection
Page 30 of 170
11/03/2016
CHAPTER 2 – INSTALLATION
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913
Ph.: 800-526-0288
2
) for each 4000 BTUs (1.17 kW)
OMM-0119_0A
GF-130-I