Lochinvar COPPER-FIN CW 745 - Manual (Page 8)

6 L o c h i n v a r D E S I G N E R ’ S G U I D E C O P P E R - F I N W A T E R H E A T E R 6 1 5 - 8 8 9 - 8 9 0 0
Btu (22 cm 2 per kW) of input, but not less
than 100 square inches (645 cm 2 ).
If a single combustion air opening
is provided to bring combustion
air in directly from the outdoors,
the opening must be sized based on a
minimum free area of one square inch
per 3000 Btu input (7 cm
2 per kW). This
opening must be located within 12 ”
(30 cm) of the top of the enclosure.
CONTAMINANTS
Combustion air drawn from an interior
or exterior space must be free of any
chemical fumes which could be corrosive to
the water heater.
Burning chemical fumes results in the
formation of corrosive acids which attack the
water heater, cause improper combustion
and premature failure of the water heater
and vent.
These fumes are often present in areas
where refrigerants, salts, and solvents are
used. Therefore, be aware of swimming
pool equipment, water softening, and
cooling system placement.
VENTING
General
Copper-Fin II Water Heaters are classified as
Category I appliances when tested to the
latest ANSI Standard. This classification
requires all conventionally vented
combustion products to be vented using
Category I listed vent pipe.
Additionally, it is recommended that this vent
material be double wall construction or
insulated in the field. A Category I
appliance operates with a non-positive static
vent pressure and with flue loss greater than
17 percent.
Vent installations for connection to gas vents
or chimneys must be in accordance with
Part 7, “Venting of Equipment,” of the latest
edition of the National Fuel Gas Code, ANSI
Z223.1, or applicable provisions of the local
building codes.
The connection from the appliance vent
to the stack must be as direct as possible
and sized correctly. The horizontal breeching
of a vent must have at least 1/4
” rise per
linear foot. The horizontal portions should
also be supported for the design and weight
of the material employed to maintain
clearances, prevent physical damage and
separation of joints.
The connection from the appliance vent
to the stack or vent termination outside the
building must be made with listed
Lochinvar
4.
(FIG. 6) COMBUSTION AIR FROM OUTSIDE,
SINGLE OPENING
CAUTION!
EXHAUST FANS:
Any fan or equipment
which exhausts air
from the equipment
room may deplete the
combustion air supply
and/or cause a down
draft in the venting
system. If a fan is used
to supply combustion
air to the equipment
room, it must by sized
such to make sure that
it does not cause drafts
which could lead to
nuisance operational
problems with the
water heater.