Lochinvar 497 - 2067 Water Heater User Manual


 
14
1 Determine unit location
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 (see FIG. 1-5).
One Opening
The opening must have a minimum free area of one square
inch per 3000 Btu input (7 cm
2
per kW). You must locate this
opening within 12'' (30 cm) of the top of the enclosure.
Combustion Air Options
Under no circumstances should a mechanical
room ever be under a negative pressure.
Particular care should be taken when exhaust
fans, clothes dryers, compressors, air handling
units, etc., take away air from the inlet.
Figure 1-5_Outside combustion air single opening
Two Openings
The combustion air opening must have a minimum free area
of one square inch per 4000 Btu input (5.5cm² per kW). You
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 input (5.5cm² per kW). You
must locate this opening within 12'' (30cm) of the top of the
enclosure.
Figure 1-6_Outside combustion air, two openings
2. Outside Combustion Air, Using Ducts
You can direct outside combustion air to this unit using two air
ducts to deliver the air to the boiler room.
Each of the two openings must have a minimum free area of one
square inch per 2000 Btu input (11cm² per kW).
Figure 1-7_Outside combustion air, using ducts
ƽ CAUTION
Installation & Service Manual