Cooling towers can produce high levels of noise pollution, which faces stringent noise regulations and laws. Therefore, companies have to abide by these rules and make sure the noise they produce is in accordance.
This can be hard for certain applications that produce huge out loads where sound reduction is imperative for example medical facilities, residential areas, and office buildings.
The primary sources of noise from cooling towers are the following:
- The fans, fan motors, and the airflow
- The droplets of the falling water hitting the basin (Waterfall noise)
Thankfully, there are noise control solutions that can be implemented where possible, as follows:
1. Use premium efficiency cooling fans
With a proper aerodynamic design using optimised blade profiles and inserts, a new cooling fan would reduce the noise where it is generated, without reducing the efficiency of the fan.
2. Consider new drives or motors
Regulate the rotational speed of the fan with a variable-frequency drive, reduces sound and saves energy on down periods or low temperatures.
3. Implement noise reduction solutions
Reduce the impact noise of the water droplets caused when they fall into the basin by implementing noise reduction mats that float on the surface of the basin water. The flexible surface of the mats becomes the collision point for the droplets as opposed to the inflexible surface of the water meaning that the emitted sound energy would be decreased.
4. Optimise initial design
Carefully consider the initial design of your equipment to make sure everything is optimised for the size and energy required, preventing any excess power or speed being used, as they are both contributors to noise.
Prevent the propagation of sound by implementing absorbing silencers, create louvered air inlets, or build sound barrier walls. These are all options worth considering if it is not possible to modify or replace the noise sources or current technology.