Lochinvar F0600187510 - Manual (Page 9)

9
Installation and Service Manual
2. Outside Combustion Air, Using Ducts
You can direct outside combustion air to this pool heater using
two air ducts to deliver the air to the equipment room. Each of
the two openings must have a minimum free area of one square
inch per 2000 Btu input (11cm
2 per kW).
3. Outside Combustion Air, Using Direct Venting
With this option, you can connect combustion air vent piping
directly to the pool heater. See the information under Direct
Venting starting on page 21 for specific information regarding
this option.
4. Combustion Air from Interior Space
You can direct combustion air to this pool heater using air from
an adjoining interior space. You must provide two openings
from the equipment room to the adjoining room.
Each of the two openings must have a net free area of one
square inch per 1000 Btu input (22cm
2 per kW), but not less
than 100 square inches (645cm 2 ).
Figure 8 – Outside Combustion Air Through Ducts
Figure 9 – Combustion Air from Interior Space
All dimensions are based on net free area in square inches. Metal
louvers or screens reduce the free area of a combustion air opening
a minimum of approximately 25%. Check with louver
manufacturers for exact net free area of louvers. Where two
openings are provided, one must be within 12" (30 cm) of the
ceiling and one must be within 12" (30 cm) of the floor of the
equipment room. Each opening must have a minimum net free
area as specified in TABLE–C, page 12. Single openings shall be
installed within 12" (30 cm) of the ceiling.
The combustion air supply must be completely free of any
flammable vapors that may ignite or chemical fumes which may be
corrosive to the pool heater. Common corrosive chemical fumes
which must be avoided are fluorocarbons and other halogenated
compounds, most commonly present as refrigerants or solvents,
such as Freon, trichlorethylene, perchlorethylene, chlorine, etc.
These chemicals, when burned, form acids which quickly attack the
heat exchanger finned tubes, headers, flue collectors, and the vent
system. The result is improper combustion and a non-warrantable,
premature pool heater failure.
Exhaust Fans
Any fan or equipment which exhausts air from the equipment room
may deplete the combustion air supply and/or cause a downdraft in
the venting system. Spillage of flue products from the venting
system into an occupied living space can cause a very hazardous
condition that must be immediately corrected. If a fan is used to
supply combustion air to the equipment room, the installer must
make sure that it does not cause drafts which could lead to nuisance
operational problems with the pool heater.
Vertical DirectAire™ and Horizontal DirectAire™ venting systems
have specific requirements for combustion air ducts from the
outside which are directly connected to the pool heater. See the
requirements for combustion air duct in the venting section starting
on page 12.