Noise Level
The distributed hood on the market today has a noise level of 35 to 70 dB, you should choose a machine with the noise as low as possible.
However, the noise level of the machine is also affected by the suction power factor and the way it is installed. If when you check the noise level of the machine at the supermarket, the noise level is low, but when you return to the factory, the noise level is high, this may be because you have used the highest suction capacity or installed it wrong way. In this situation, you can check or ask a technician to check for you.
Low CFM does not always imply low noise; you also want a hood with a powerful motor. A 1000 CFM hood, for example, may have a quieter motor than a 600 CFM hood. It is dependent on the materials used and the production process employed. When you're out shopping, keep this in mind.