Combustion Air Options - Lochinvar 399 Installation And Service Manual

FIG. 4 Metal Panel Covering Side Combustion Air Inlet
FIG. 5 Moving Air Filter/Bracket Assembly from Rear of
Unit to Side
Installation and
Service Manual

Combustion Air Options

CAUTION: Under no circumstances
should the mechanical room ever be under a
negative pressure. Particular care should be
taken where exhaust fans, attic fans, clothes
dryers, compressors, air handling units, etc.,
may take away air from the unit.
This unit has four combustion air options.
1. Outside Combustion Air, No Ducts
You can direct outside combustion air to this unit using either
one or two permanent openings.
One Opening
The opening must have a minimum free area of one square
inch per 3000 Btu input (7cm
opening within 12" (30cm) of the top of the enclosure.
FIG. 6 Outside Combustion Air - Single Opening
Two Openings
The combustion air opening must have a minimum free area of
one square inch per 4000 Btu/hr input (5.5cm
must locate this opening within 12" (30cm) of the bottom of
the enclosure.
The ventilation air opening must have a minimum free area of
one square inch per 4000 Btu/hr input (5.5cm
must locate this opening within 12" (30cm) of the top of the
enclosure.
9
2 per kW). You must locate this
2 per kW). You
2 per kW). You