AERCO KC Series Equipped with C-More Controller for Massachusetts Only - Manual (Page 19)

INSTALLATION
2-9
2.7 FLUE GAS VENT INSTALLATION
AERCO Gas Fired Venting and Combustion Air
Guide, GF-1050, must be consulted before any
flue or combustion air venting is designed or
installed. Suitable, U/L approved, positive
pressure, watertight vent materials MUST be
used for safety and UL certification. Because
the unit is capable of discharging low
temperature exhaust gases, the flue must be
pitched back towards the unit a minimum of 1/4"
per foot to avoid any condensate pooling and to
allow for proper drainage.
While there is a positive flue pressure during
operation, the combined pressure drop of vent
and combustion air systems must not exceed
140 equivalent feet of 0.81” W.C. Fittings as
well as pipe lengths must be calculated as part
of the equivalent length. For a natural draft
installation the draft must not exceed - 0.25”
W.C. These factors must be planned into the
vent installation. If the maximum allowable
equivalent lengths of piping are exceeded, the
unit will not operate properly or reliably.
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.