The higher the temperature within the server space, the greater the need for cool air from your air conditioning system and its delivery to your server racks either via a raised access floor or general movement via fans within the room. The harder the air conditioning system must work, the greater the energy used and the higher the running costs in terms of electricity bills. Computing and server equipment generate heat, as a by-product of their microprocessor activities. When placed within a serve rack the heat can build-up to create uneven temperatures within the racks, ‘hot-spots’ and potentially areas where the electronics could overheat to a point of failure and/or present a fire risk.
A standard server rack will be designed for installation within a server room or datacentre type environment. The rack is basically a four-post frame to which side panels, and front and rear doors are attached. The side panels are typically unvented and removable. The front door may be vented, meshed or made from glass and the rear door may be an option (for ease of access) and if fitted vented. Equipment is placed into the rack using slide rails that attach to the posts or pillars or sits onto fitted shelves.
The front door of the rack may include a locking handle with biometric, keypad or card access control. Thermal management and monitoring are a must within any server room environment, and this must be deployed at both the room and rack levels.
Custom build options could include liquid-cooled rear panels doors, built-in air conditioning units, overhead metal returns or the use of a cold or hot-aisle arrangement. The standard rack has an IP-rating of 20 but this can be increased to IP54 or higher for environments requiring more ruggedized designs.
For any server rack it is important to ensure that the cool air supplied via the front of the rack, reaches all the IT equipment within the rack and passes through as efficiently as possible. Any exposed gaps provide an opportunity for air to escape to the space outside the racks and should be closed. This is the principle purpose for front blanking panels. Any side panels spaces should also be sealed and when supplied the side panels must be installed.
A solid air flow strategy can have several benefits. Efficient air flow reduces demand on local air conditioners and improves energy efficiency. With a local load on the air conditioners, the IT load can be expanded more easily through the introduction of more server hardware into the racks or more racks into the server room (assuming there is physical space). The removal of ‘hot-spots’ removes fire risk and helps improve the overall operating life of the IT hardware within the racks. Long term, excessive heat can also damage network and electrical cable insulation.
Server rack air flow management focuses efficiently managing air flow through the rack and to the exhaust channel. Any open or unsealed spaces reduce air flow efficiency. Recommendations for improving air flow should therefore consider:
For more information on energy efficiency within a datacentre see the EU Code of Conduct for data centres.
The long-term benefits of an efficient air flow within a server rack or network cabinet include reduced running costs, improved hardware reliability and potentially a longer working life for the systems involved. Often it is relatively easy to identify quick wins in terms of ‘escape spaces’ for both cool and hot exhaust area. The use of thermal cameras during site surveys can also provide additional data for analysis and help to identify ‘hot-spots’ and areas for concern within the racks themselves. Dependent upon the number of racks involved, hardware consolidation can provide further improvements, as can the use of a cold or hot-aisle containment solution.
Data centres and server rooms should be designed around the workload they have to support both from day-one and in the future. This is not always the case and many server room operations evolve from their initial concept, driven by changes in demands, workloads and technology. This can lead to inefficiencies and less than optimum design in terms of critical systems and resilience.
When it comes to room design, it is vital to ensure you make the right choices in the selection of your server racks and cabinets. There are several topics to consider, all of which can impact the overall layout optimisation, functional efficiency and the future scalability of your room design.