Minimum Clearances – Indoor
CLEARANCES
The heater must have both combustion air and
ventilation air.
• Ventilation air opening 12”(305 mm) max from
the ceiling
• Combustion air opening 12”(305 mm) max
from the floor
All air from outdoors, each opening shall have a
net free area as shown in table.
Check state and local codes before proceeding. Some states do not recognize the NFGC and require larger openings.
6
Model
Unrestricted
Opening
Sq. In. (m
2
)
Typical
Screened or
Louvered
opening
Sq. In. (m
2
)
Typical
Screened and
Louvered
opening
Sq. In. (m
2
)
264
66 (0.04)
99 (0.06)
132 (0.09)
404
100 (0.06)
150 (0.1)
200 (0.13)
