Can data centres ever be cool?
The nature of a data centre is such that it generates enormous amounts of heat. Keeping servers cool enough to handle heavy modern workloads therefore requires out-of-the-box thinking.
The International Data Corporation (IDC) has predicted that humans and machines will generate in the region of 175 zettabytes of data by 2025. With such huge quantities of information being generated and needing to be stored, this will have a range of impacts on both current data centres and future data centre design.
Denver Pillay, IT Account Manager at Rittal, suggests that as increasingly larger amounts of data are being collected and stored, companies will need to invest more heavily in their data centre infrastructure and hardware.
“Obviously, such an approach requires huge capex investments, which is why companies are now, more than ever, shifting towards the cloud. After all, cloud providers offer these companies the infrastructure they require, but without the huge capex investment,” he says.
“Of course, even the cloud ultimately resides on physical hardware somewhere, and with a growing demand for capacity, the storage devices used will need to be able to store more data, and this information will need to be processed faster. Moreover, there is also a demand for hardware that has a smaller footprint, which in turn means greater heat generation, because the smaller device finds itself working harder.”
These factors, points out Pillay, will impact on data centres in two ways, namely, it will mean they will be consuming more energy and this, in turn, will mean that need to dissipate more heat. The obvious conclusion, he adds, is that data centres will need to accommodate additional cooling and power to meet these demands.
“The net result of this is that data centres will need to consider alternative sources of power, such as renewable energy solutions, and new ways of cooling, such as free or hybrid cooling.
“Power usage effectiveness (PUE) describes how efficiently data centres use energy under normal operating conditions. Since the aim is to maximise the power available for the physical hardware and minimise the amount of power used by other technologies – like cooling and lighting – it is imperative to find ways for these to lower their power consumption. From a lighting perspective, energy efficient solutions can be implemented, and a similar approach can be used for cooling.”
He explains that by utilising inverter cooling, this aspect of the data centre can return a lower PUE contribution.
“With inverter cooling, for one thing, there is a ‘Soft Starter’ function that reduces the demand on the power grid and backup generators. It also offers a quick and precise match to cooling demand. Having this kind of close control over the compressors enables greater energy savings than could be achieved with fixed-speed compressors,” states Pillay.
“Another method is to implement free cooling, when ambient temperatures are lower, compressors on the coolers will ramp down and fans will circulate the cold air in the data center. This can reduce the data centre’s reliance on mechanical air conditioning and lower its overall energy consumption.”
Naturally, geographic location plays a prominent role in how well a data centre can utilise the principle of free cooling.
“Obviously, free cooling is not an option for every data centre, as challenges like hot and humid outdoor conditions, inadequate filters and sensitive legacy equipment can all create insurmountable problems. However, when it is implemented correctly, free cooling can significantly reduce the need for artificial air conditioning, and thus lower your overall costs and energy consumption.
Asked what these new cooling methods may mean in the long run, Pillay indicates that for large-scale data centre builds, it shows that the location is going to become increasingly critical. More businesses will seek to build their centres in colder areas, perhaps where there is also access to free water that can be used to run turbines, thereby providing access to off-the-grid power.
“For the medium-sized data centre builds, the main thing that organisations will have to focus on in respect of their cooling needs is their return on investment (ROI). Too often, businesses go for the solution that offers the lowest capex costs, without truly considering things like operational expenses, maintenance costs and potential future expansions. However, when capex is taken off the table and ROI becomes your focus point, options like inverter and free cooling become obvious routes to increasing this,” he concludes.