Noise and other disturbing noises might have a negative effect on our health, according to the Swedish Public Health Agency. Noise can cause sleeping difficulties, increase the risk of cardiovascular disease, impede learning, and more. There are also many who suffer from various noise problems. According to the WHO, almost one in three Europeans is negatively affected by noise, and one in five is exposed to noise that can have a clear negative impact on health.
A common source of these noise pollutants is the fans used in ventilation systems. They produce a so-called tonal sound that occurs when the blades of the fans move. Researchers and fan manufacturers have long tried to come up with methods to reduce the noise from the fans. Now researchers from the Chalmers University of Technology in Sweden have managed to identify the source of the problem and also developed a solution.
"The source of the tonal sound has never before been identified on this type of fan. When you reduce this tone, the fans become extremely quiet and in that way also world-unique. This is the first time someone has succeeded in solving this problem", says Martin Ottersten, industrial doctoral student in fluid mechanics at Chalmers and the researcher behind the study, in a press release.
To identify the source of the problem, Martin Ottersten ran advanced computer calculations to see air flowing through the fan during rotation. The calculations showed where the turbulence was and gave data to locate the source of the disturbing sound.
With that information, Martin Ottersten has succeeded in constructing a fan that is both extremely quiet and efficient.
"By modifying fans and measuring the sound levels using very large calculations on hundreds of computers for several weeks, I could see exactly where in the fan's construction the tonal sound occurs and how it can be eliminated. Another positive effect we have been able to see is that the efficiency of the fan has increased when the tonal sound has decreased", says Martin Ottersten.
The next step will now be to transform the discovery into a finished product.
"We are currently patenting the solution and implementing it in our fans. Then we will get them on the market and help make our indoor environments healthier to stay in. And also reduce energy consumption and carbon dioxide emissions on the purchase", says Martin Ottersten.