Size

Nominal fan diameter in inches (1 inch = 25.4 mm)

 

Cone

Y = yes, N = none
The discharge cone attaches to the exhaust side of the fan and expands gradually

 
Shutter
Type
A = Aluminum
B = Butterfly Damper
G = Galvanized Steel
P = Plastic
R = Roll Seal

 
Airflow 0.05" SP cfm

cfm or cubic feet per minute
(1 cfm = 1.699 m³/hr.) (0.05"SP = 12.5 Pa)

 
VER 0.05" SP cfm/Watt

Ventilating Efficiency ratio (cfm/Watt)
The higher the VER the more efficiently a fan uses electricity.

 
Airflow 0.10" SP cfm

cfm or cubic feet per minute
(1 cfm = 1.699 m³/hr.) (0.10"SP = 24.9 Pa)

 
VER 0.10" SP cfm/Watt

Ventilating Efficiency ratio (cfm/Watt)
The higher the VER the more efficiently a fan uses electricity.

 
Airflow Ratio
The airflow at 0.20" SP divided by the airflow at 0.05" SP. A high Airflow Ratio provides fairly constant airflow as wind speed varies.