3-12
INSTALLATION WITH AN EXHAUST
HOOD
AIR VELOCITY
In most cases, the exhaust pipe from the ICO extends into the
open hood area above the hood intake edge. The air velocity at
the hood intake edge must be sufficient to prevent smoke from
escaping.
Figure 8: ICO Exhaust Pipe Below the Hood Intake Edge
The air velocity at the hood intake edge is a function of the hood
exhaust fan capacity and the area of the hood opening.
EXAMPLE
• Hood exhaust fan capacity = 2,500 ft.
3
/min.
• Hood opening = 4 ft. x 5 ft. = 20 ft.
2
• Air velocity at hood intake edge = 2,500 ft.
3
/min./ 20 ft.
2
= 125 ft./min. = 2 ft./sec.