Harsco Industrial MACH C1500GG Installation & Owner's Manual page 14

Air Inlet Requirements – United States (NFPA 54/ANSI Z223.1 & NFPA/ANSI 211)
3.5.2.1
When air is supplied from inside the building, the total required volume shall be the sum of the required volume for all
the appliances located in the mechanical room. Adjacent rooms furnished with fixed openings communicating directly
with the mechanical room are considered part of the required volume. The minimum volume is 50 ft
3
(4.8 m /kW) of installed appliance input capacity.
Openings used to connect indoor spaces to obtain the required minimum volume shall be sized as follows:
When rooms are on the same floor, each opening shall have an area equal to 1 square inch for each 1000 Btu/hr
2
(2200 mm / kW) of installed appliance input capacity, but not less than 100 square inches. One opening should
commence less than 12 inches above the floor and the other less than 12 inches below the ceiling. The minimum
dimension of air openings shall be 3 inches.
When rooms are on different floors, each opening shall have an area equal to 2 square inches for each 1000
2
Btu/hr (4400 mm / kW) of installed appliance input capacity.
When combustion air is supplied from outside the building, the boiler room shall be provided with one or two openings
to ensure adequate combustion air and proper ventilation.
When using one permanent opening, the opening shall commence within 12 inches of the ceiling and shall
communicate directly with the outdoors or through a vertical or horizontal duct that communicates to the outdoors.
Minimum free area of the opening is 1 square inch for each 3000 Btu/hr (700 mm
input capacity, and
Not less than the sum of the areas of all vent connectors in the room.
When using two permanent openings, one opening shall commence within 12 inches above the floor and the other
within 12 inches below the ceiling, preferably on opposite walls. The openings shall communicate directly, or by way
of ducts, with free outdoor air. The minimum net free area of the openings shall be calculated in accordance with the
following:
When air is taken directly from outside the building, each opening (minimum of two, as outlined above), 1 square
inch for each 4,000 Btu per hour (550 mm
When air is taken from the outdoors through a vertical duct into the mechanical room, 1 square inch per 4,000 Btu
2
per hour (550 mm /kW) of total boiler input is required.
When air is taken from the outdoors through a horizontal duct into the mechanical room, 1 square inch per 2,000
Btu per hour (1100 mm
NOTE:
1. The required size of openings for combustion and ventilation air shall be based on the net free area of the
opening.
2. Screens shall be not smaller than ¼"
3. Motorized louvers shall be interlocked with the appliance so that they are proven open prior to main burner
ignition and operation.
Table of US Minimum area of ventilation openings per boiler (sq inches)
MACH® Boiler
MODEL
C1500GG
C2000GG
2
/kW) of total boiler input is required.
2
/kW) of total boiler input is required.
INDOOR AIR SUPPLY
SAME DIFF
FLOOR FLOORS
1500 3000
2000 4000
AIR SOURCE
ONE
OPENING
500
667
Page 14
MACH® Gas-Fired Boiler
3
per 1000 Btu/hr
2
/ kW) of installed appliance
OUTDOOR AIR SUPPLY
TWO OPENINGS
VERT
DIRECT DUCT
375 375
500 500
HORIZ
DUCT
750
1000