The more servers that are added to a datacentre, the more cooling that centre is likely to need. And the more cooling those servers require, the greater the “whoosh” generated. Whoosh, for the uninitiated, is the annoying noise of fans and humming power supplies that can feel like pressure building in your head.

Datacentre workers live with this noise. But there may be reason to start giving it more attention: Datacentre consolidations and the adoption of high-density equipment - both big industry trends - are bringing more equipment and denser and hotter systems into datacentres.

There’s a dearth of scientific data on noise in datacentres, its health consequences and its impact on productivity. Noise is simply taken for granted by datacentre managers, who spend little, if any, time measuring sound levels. For the most part, workers just learn to deal with it.

“It’s pretty loud; it’s pretty stressful,” says computer operator Bruno Skiba, who works at a financial services firm and wears ear protection devices similar to the ones used on firing ranges.

Noise, of course, varies from centre to centre, system to system. It’s now fairly common for datacentre workers to spend a lot of time off the datacentre floor managing systems in separate rooms. While some racks have whiny, high-speed fans, some Itanium-based servers from HP have larger fans that are less noisy. Skiba’s firm, which he declined to identify, recently got a delivery of those quieter servers.

A looming problem

The noise generated by the equipment in a datacentre can be distracting. That fact prompted datacentre workers at C I Host to get Bose noise-cancelling headphones, says Christopher Faulkner, CEO of the Dallas-based hosting company.

“The noise - the pressure on their head, if you will - is very distracting and causes serious issues with [workers] being able to concentrate and do their jobs,” says Faulkner.

Faulkner says he has never measured the noise in his datacentre. That doesn’t surprise Tad Davies, executive vice president of Bick Group, a company that designs and builds datacentres. Davies says he can recall only one IT manager who asked for sound-level measurements. “It’s been, universally, an issue that has not been brought up,” he says.

Davies, without naming the customer, shared a diagram of the datacentre showing the decibel levels taken in 12 different places in the facility. The lowest was 70 decibels, and the highest was 79 decibels. The highest levels were recorded near heating, ventilation and air conditioning equipment. You have to talk loudly to be heard at those levels, but they are considered safe according to US Government standards. The federal government doesn’t require action until workers are exposed to average noise levels of 85 decibels or greater.

Dr Peter Rabinowitz, a member of the American College of Occupational and Environmental Medicine’s Sensory Perception Committee, says he is unaware of any research specifically on noise in datacentres. While the Occupational Safety and Health Administration (OSHA) calls for steps such as the use of ear protection if workplace noise reaches a certain level, he notes that even low-level noise from fans, air-handling systems and other typical datacentre gear can affect concentration and produce fatigue.

What’s too loud?

There is no agreed-upon standard for the decibel level at which datacentre workers must be protected. If the noise level reaches 85 decibels, that triggers some monitoring under OSHA regulations. If it hits 90 decibels, companies are required to take steps to protect workers’ hearing. In contrast, Europe’s workplace protections begin at 80 decibels.

The question is whether anyone’s measuring. “I’m not aware of studies that have demonstrated that working in a datacentre exposes you to hazardous noise. However, there certainly could be something out there,” says Mark Stephenson, a senior research audiologist and coordinator of hearing research at the National Institute of Occupational Safety and Health, which is part of the US centres for Disease Control and Prevention.

“The trend toward larger and larger facilities would have a slow incremental increase in the noise level, so it’s possible that something like [crossing the legal threshold for action] would creep up,” he says.

Whether noise is an issue for an IT manager may depend on the type of datacentre.

In some future scenarios - think of this as the ultimate lights-out datacentre - the facility might be, in total, a computer: a highly interconnected operation with self-healing, self-configuring systems that’s managed remotely and is rarely entered by personnel. Noise won’t matter as much.

But most datacentres are far from the lights-out ideal, and they’re run by people like Nick Martin, IT manager at Taco Metals, a maker of marine products. Martin has been in IT since the 1970s and says noise reduction has always been important to him. He especially likes to be able to talk on the phone with a vendor when he’s working on equipment - something that once was impossible in his datacentre.

Martin replaced his ceiling tiles with acoustic tiles and installed the same sound-deadening tiles on some of the datacentre’s walls. “It really knocked the sound down quite a bit,” he says.

If he uses a headset, Martin says, it’s now quiet enough to “go from my office to the computer room working with the Microsoft tech flawlessly, so there is no interruption in tech support.” That matters a lot, he says, because it helps avoid downtime.