Vanguard Heating VS24PR - Manual (Page 7)

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103448
WARNING
If the area in which the heater may be operated is smaller than that defined as an uncon-
fined space, provide adequate combustion and ventilation air by one of the methods
described in the
National Fuel Gas Code, ANSI Z223.1, 1992, Section 5.3.
Outlet
Air
Ventilated
Attic
Outlet
Air
Inlet
Air
Inlet Air
Ventilated
Crawl Space
To
Crawl
Space
To Attic
Or
Remove
Door into
Adjoining
Room,
Option
3
Ventilation Grills
Into Adjoining Room,
Option 2
Ventilation
Grills
Into Adjoining
Room,
Option 1
12"
12"
AIR FOR
COMBUSTION
AND
VENTILATION
Continued
VENTILATION AIR
Ventilation Air From Inside Building
This fresh air would come from an adjoining unconfined space. When ventilating to an adjoining uncon-
fined space, you must provide two permanent openings: one within 12" of the ceiling and one within 12"
of the floor on the wall connecting the two spaces (see options 1 and 2, Figure 2). You can also remove
door into adjoining room (see option 3, Figure 2). Follow the National Fuel Gas Code NFPA 54/ANSI
Z223.1, Section 5.3, Air for Combustion and Ventilation for required size of ventilation grills or ducts.
WARNING
Rework worksheet, adding the space of the adjoining unconfined space. The combined
spaces must have enough fresh air to supply all appliances in both spaces.
Figure 2 - Ventilation Air from Inside Building
Ventilation Air From Outdoors
Provide extra fresh air by using ventilation grills or ducts. You must provide two permanent openings: one
within 12" of the ceiling and one within 12" of the floor. Connect these items directly to the outdoors or
spaces open to the outdoors. These spaces include attics and crawl spaces.
IMPORTANT: Do not provide openings for inlet or outlet air into attic if attic has a thermostat-controlled
power vent. Heated air entering the attic will activate the power vent.
Figure 3 - Ventilation Air from Outdoors