Sound & Noise Reviews

Noise is a pollutant as well!

Sound & noise reviews are usually required for industry if there is a residential, educational or institutional building within 100 metres of the site, but, under certain circumstances, may not be asked for if the distance is less.
The MOE criteria calls for no higher noise emission from the company than the normal 'background' noise level at the point of reception.

Noise reviews are considered necessary when the Ministry deems there may be an issue based on the distance, receptor, type of exhaust fan, rpm's and the exhaust stack specifications. True noise reviews are done 'on site' and give an exact output of fan noise in relation to the normal background noise at the receptor. The sound data logger is installed at the point of reception:

(click images for bigger view)

Readings are taken for a period of 20 minutes with the equipment on to determine the true fan noise level. The data logger outputs the information in graph and text format:

Average Reading Fan On = 57 db

The high peaks are caused by things such as passing vehicles, aircraft, or intermittent shop noise. This interference is removed from the final calculations.

Readings are then taken for 20 minutes with the equipment off to determine the 'background' noise level and set a base for our calculations.

As you can see, intermittent background noises are no longer hidden, or masked, by the fan noise. Again, the peaks are removed for accuracy.

Average Reading Fan Off = 53db

This test resulted in a 4db over background noise level, but with the 'peaks' removed, it dropped to 3db.

We would consider a change in fan blade type, an exhaust silencer (muffler) or other ways to resolve the issue.