Custom Range Hoods: Range hood Noise and how to manage it

Saturday, February 4, 2012

Range hood Noise and how to manage it

The critical factors in noise reduction are:

- Type of filters

- Quality of duct work – appropriate size for the airflow, length and number of bends

- Quality and size of blower used

Filters:

There are in essence two types of filters – mesh and baffle. Baffle filters are quieter, 96% efficient and excellent fire travel blockers. Mesh are only recommended in lower cfm applications around 400cfm to 600cfm and over electric style cook tops.

Quality of ductwork:

The most critical element is the size and quality of duct material relative to the maximum airflow you try to move down that duct – for 400cfm internal blowers we recommend 7”, for 600cfm internal blowers 8” and 1200cfm internal blowers 10”. Inline blowers between 600 and 1000cfm need 8” duct and external blowers of 1000cfm 8” duct. Rigid metal duct is strongly recommended – flexible ribbed ducting will be noisy because the air is “tripping” of the ridges and makes noise.

The average duct length and number of bends found today is not too much of an issue – if bends and length is excessive then external blowers and more powerful blowers should be used – if a blowers is trying to “PUSH” a high volume of air down a long and wavy duct run the motor needs to work harder and of course will be noisier.

Blowers:

These come in all forms of quality – the quality blowers have less mechanical noise because they are well made and balanced.