
Whether you are running an in-house enterprise server room or colocation datacentre, critical power and cooling are key environmental factors that must be managed to prevent IT system operating errors, erroneous alarm conditions, data processing errors, system malfunctions and unexpected shutdowns.
Thermodynamic airflows are an important aspect to consider when designing a server room or datacentre environment. All electronic devices generate heat and the amount of heat generated by an IT server can greatly impact its operating environment. A typical rack cabinet will typically house more than one server and the greater the number installed, the larger the heat dissipated into the server room or datacentre white space. In a typical datacentre ratings of 15-30kW are no common for a fully loaded server rack cabinet and overall consumption for a server room can typically be up to 200kW and for a datacentre up to several hundred Mega-Watts.
If not managed, any residual heat build-up can reach dangerous levels. This can be within individual server cabinets or ‘hot-spots’ within the overall IT white space. Insufficient airflow can also be a problem for poorly designed environments leading to un-managed temperature fluctuations, poor energy efficiency and the need for additional cooling systems to be added post commissioning.
The electronics within a modern server require a large amount of electrical power and this is usually supplied as a direct current (DC) via an internal Switch Mode Power Supply (SMPS) which is itself connected to an alternating current (AC) power sources. Within a critical power environment, servers are usually connected to a server cabinet power distribution unit which is itself connected to an uninterruptible power source.
Cool air is typically drawn into a server via internal fans and is drawn over the electronics circuits. The warmed air is then expelled out of the server case via the fan exhaust system. This arrangement benefits server room or datacentre design as it allows for server cabinet rows to be arranged in a uniform manner and typically in a ‘hot-aisle/cold-aisle’ arrangement. From a cooling system perspective, cool air must be supplied to the front of the server cabinets and rows and taken back into the cooling system from the rear of the server cabinets.
Whilst the fan arrangement within a typical server is sufficient to cool a typical server, the build-up of heat within a confined space like a rack cabinet of two or more servers can be excessive. If this heat build-up is not reduced, temperatures can rise to a point where the servers will fail and potentially pose a fire risk. In some environments, humidity levels are naturally higher than others and increased humidity levels can also cause server room failures, corrosion and rust.
Most IT and other electronic systems can operate up to 40°C and 95% relative humidity without derating these conditions are not suitable for people to work within. For a server room or datacentre environment temperatures of 20-25°C with a relative humidity of 40-55% are recommended. It should be noted that the ASHRAE standard continues to consider raising the operating temperature for server environments to towards 30°C as this would reduce cooling requirements and therefore improve energy usage and overall operating efficiency.
IT facilities run 24/7 and just as they need uninterruptible power to maintain their services and uptime, so must the cooling be 24/7 and uninterrupted. When IT systems are installed in their own dedicated room such as a server room or micro-datacentre, they need to be supported by their own dedicated cooling systems.
As with any critical IT system, redundancy should also be built-into the design, as well as remote monitoring. Redundancy in the design whether N+1 or 2N caters for not only cooling system failure but also the ability to carry out maintenance without interruption to the cooling system(s) and IT system shutdown. Other aspects to consider include:
A well designed, installed and maintained air conditioning and cooling system is a key component of any server room or datacentre environment. The right design, installation and maintenance will give you a cooling system that can support your IT strategy and future growth plans.
Whether you are planning a new installation or upgrade or simply want advice on an existing system please contact the Server Room Environments team for a free site survey and project review. Our team can provide references across the UK for a range of environments, installations and building types.