Are data centers actually noisy, and is this bad for our health?

Data centers, those large buildings housing vast amounts of computer equipment, have been generating noise concerns in recent years. This issue has sparked debates in various countries, including the United States and Australia. While there is limited data linking environmental noise from data centers to health effects, experts do have some insights into the noise these facilities produce and its potential impact on our well-being.

Sound intensity is measured in decibels (dB), but the human ear perceives sound differently. Adjusted for this perception, we use a weighted scale called dBA. For perspective, a rustling leaf generates around 30 dBA, background music reaches about 60 dBA, and a typical office environment sits at approximately 70 dBA. Generally, sounds below 70 dBA are considered safe for long-term exposure to our health.

However, once we cross this threshold, the risk of hearing damage increases. For instance, the World Health Organization (WHO) advises that workers should not be exposed to 85 dBA (the noise level of a lawn mower or leaf blower) for more than eight hours without risking hearing damage.

Data centers rely heavily on cooling systems to regulate their internal temperatures. These systems include air-handling units, air-cooled chillers, cooling towers, and pumps, all of which generate noise. Additionally, backup generators are employed during power disruptions or during maintenance checks. Both the air-handling units and backup generators can produce noise levels exceeding 85 dBA within the facility.

To comply with environmental regulations, data centers employ various noise mitigation strategies. These include using quieter cooling equipment, employing careful building design, and utilizing soundproofing equipment like acoustic louvers, physical barriers, and silencers. Companies proposing new data centers must demonstrate that their construction will not exceed predefined noise limits, which are set by states and territories based on surrounding land uses.

These limits often restrict nighttime noise to 35–40 dBA in residential areas and mirror the WHO's 2018 guidelines for Europe.

The approval process in Australia includes an independent noise assessment, ensuring the data center will not exceed these limits, especially during nighttime hours. Additionally, measures to prevent the growth of background noise, known as "noise creeping," are implemented. This involves adjusting individual noise limits if surrounding land already nears the acceptable threshold, particularly when multiple data centers are proposed close together.

Recently, Victoria's EPA raised concerns about a proposed data center in Campbellfield, Melbourne's north, citing potential noise impacts on nearby residents. Similarly, a proposed data center in Hazelmere, Western Australia, featuring 64 rooftop chillers and 88 diesel generators, faced rejection by its local council due to concerns over noise effects on residents, a school, and proximity to a river and Aboriginal cultural sites.

While evidence linking environmental noise, including data center noise, to health effects is lacking, a 2015 review by the Australian National Health and Medical Research Council found no direct evidence that wind farm noise affects physical or mental health. Given the similarity in noise levels, some experts draw parallels between data centers and wind farms.

In the short term, excessive noise from any source, including data centers, can lead to annoyance, which may result in stress-related health issues. However, as long as noise remains within recommended levels, annoyance tends to diminish over time. The noise limits set for data centers in Australia align with WHO guidelines, indicating that current regulations aim to protect public health from potential noise-related health effects.