What is the CFM rate and what is a sone?
CFM, which is the measurement unit for exhausting air flow, stands for cubic feet per minute. The higher the CFM number, the greater the amount of air that is exhausted when using the range hood.
A sone is an internationally recognized measurement unit for loudness that can provide an accurate indication of what humans can hear. If the number of sones is doubled, the loudness of a noise is also doubled (i.e., if a unit produces 2 sones of noise and another unit produces 4 sones, the second unit is twice as noisy as the first).
One sone is equal to the soft hum of a refrigerator in a noiseless kitchen. All data on CFM rates and noise levels for Venmar, Venmar Connaisseur and Venmar Jazz range hoods are certified by the Home Ventilating Institute (HVI).