8 combustion air, 1 combustion air from outside the building, 2 combustion air from inside the building – AERCO KC Series Equipped with C-More version 3.04 User Manual
Page 19: 3 sealed combustion, Installation

INSTALLATION
2-9
For Massachusetts installations, the Heatfab
Division of the Selkirk Corporation provides vent
systems which conform to all applicable
requirements for installations within the
Commonwealth of Massachusetts. Contact
information for this supplier are as follows:
Selkirk Corporation
Heatfab Division
130 Industrial Blvd.
Turners Falls, MA 01376
Phone: 1-800-772-0739
2.8 COMBUSTION AIR
The AERCO Gas-Fired Heater Venting and
Combustion Air Guide, GF-1050 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, 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.
The more common methods of combustion air
supply are outlined below. For combustion air
supply from ducting, consult AERCO GF-1050,
Gas Fired Venting and Combustion Air Guide.
2.8.1 COMBUSTION AIR FROM OUTSIDE
THE BUILDING
Air supplied from outside the building must be
provided through two permanent openings. For
each unit these two openings must have a free
area of not less than one square inch for each
4000 BTUs input of the equipment or 250 square
inches of free area. The free area must take into
account restrictions such as louvers and bird
screens.
2.8.2 COMBUSTION AIR FROM INSIDE
THE BUILDING
When combustion air is provided from within the
building, it must be supplied through two perma-
nent openings in an interior wall. Each opening
must have a free area of not less than one
square inch per 1000 BTUH of total input or
1000 square inches of free area. The free area
must take into account any restrictions such as
louvers.
2.8.3 SEALED COMBUSTION
The unit is UL approved for a 100% sealed
combustion application when installed properly.
When a sealed combustion air application is
installed, the sealed combustion air piping must
be deducted from the maximum allowable
discharge piping amounts. Each unit must have
a minimum 6" diameter connection made to the
optional Inlet Air Adapter # GM-18917 available
from AERCO. This Adapter bolts directly on to
the air inlet of the unit blower. See installation
instructions with Adapter. All inlet air ducts must
be sealed air tight.