Combustion Air; Unit Initial Fill - Aerco KC Series Installation, Operation & Maintenance Instructions Manual

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 the 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
permanent 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
INSTALLATION PROCEDURES
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.

2.9 UNIT INITIAL FILL

Before filling the shell for the first time, blow out
all the connecting water and gas piping and
check thoroughly for leaks. Rinse all soap suds
from the gas piping with clean water. Do not
allow water to get on the Control Panel or
electrical connections. Check that all installation
procedures have been completed.
The following steps should be followed to fill the
unit:
1. Close the unit's drain valve.
2. Open the shut-off valves at the water inlet
and outlet.
3. Open the temperature/pressure relief valve
to allow air to escape from the shell. The
shell is full when water flows out of relief
valve discharge piping.
4. Close the temperature/pressure relief valve
and open fixtures in building to free the
system of air.
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