When is enough enough?

A simple question popped into my head this weekend.

How much noise it too much noise?

The frost event on Saturday morning has certainly highlighted the significant volume of noise that is produced by frost fans, but presumably this noise level is adjudged by the Marlborough District Council as reasonable.

So what constitutes a reasonable level of noise?

They have set a value for an individual machine (55dBA L10 at 300m), but this certainly doesn't take into account the hundreds of machines that operate simultaneously. Aside from one Environment Court ruling that has imposed a need to consider the noise from more than one machine cumulatively there seems to be little comprehension that more machines = more noise.

It's pretty fundamental, it has a legal precedent, and yet I not an installation of approximately 20 Frost Boss machines being installed approximately 2.5km from Renwick.

Now there are a couple of points to note here;

Firstly, Frost Boss fans have a weighty reputation for being the quietest machine on the market due to their four bladed design and subsequent lower rotation speed. However, ultimately there is a noise being produced.

Secondly, at a distance of 2.5km, people tend to dismiss the effect because it seems so far away.

So, how loud will they be?

Calculations on the back of a napkin show that 20 fans producing 55dBA L10 at 300m result in a noise of approximately 50dBA L10 at 2.5km.

This is on the cusp of being intrusive to people's sleep when they are 2.5km away! Yet was any investigation done to protect residents who were closer? (rest assured there are plenty)