Unified Brands VENTILATION SYSTEMS - Manual (Page 32)

29
CALCULATING AND RECORDING AIR MOVEMENT
1.) Cubic feet per minute or CFM'S is the total area multiplied by the average feet per
minute.
A: CFM
AREA FPM
B: CFM = AREA x AVG. FPM
FPM = CFM ÷ AREA
AREA = CFM ÷ FPM
2.) AREA is the length of the opening multiplied by the width in inches. Divide the total
by 144 to get the total square feet (area).
EXHAUST
A: Filter Hoods - Area = *Square Feet x Quantity of Filters
* 16 x 20 Filter = 1.75 Square Feet
* 20 x 20 Filter = 2.25 Square Feet
B: Extractor Type Hoods - Area = **Square Feet x Quantity of Modules
16” Standard Module
**Low Volume Extractor w/3" Slot = .32352 Square Feet
**High Volume Extractor w/4" Slot = .43136 Square Feet
9” Standard Module
**Low Volume Extractor w/3" Slot = .1855 Square Feet
**High Volume Extractor w/4" Slot = .2473 Square Feet
C: Water Wash Hood - Area = Length of Slot x Width of Slot in inches and
divided by 144 for square feet.
SUPPLY
A: Perforated Supply Air Panels - Square Feet of Panel x .4 = Area.
B: Register Type Supply Air Panels - Square Feet of Panel x .7 = Area.