How To Design An Air Conditioning Installation

When it comes to designing server room air conditioning systems the ‘one-size-fits-all’ approach just doesn’t work. Every building and room is different and will have its own thermodynamic and physical properties, usage and demands.

Whilst we are principally known for our server room and datacentre air conditioning systems, we also supply, install and maintain cooling systems for a number of other types of environment. This is our short guide to designing an air conditioning system.

As with many of the systems we supply, process starts with a site survey. This has to be just as detailed as any other survey we carry out and look at not just the room layout but entrance logistics and electrical works required. On top of this there are also a number of other factors to take into account for an air conditioning system related to room size, air flow, air entrances and exits, use of suspending ceilings and raised access floors, the equipment in the room and its heat/energy efficiency characteristics.

A logistics survey can be a complex process to gather the data but obtained we can then move onto the calculation. Here we sum the load today and what is estimated for the future and then calculate the required cooling capacity required. Couple with this we also need to work with the client to find out what their requirements are in terms of type of cooling system and the energy efficiency points they want to reach. Any other ‘green’ agenda items may also have to be included such as ‘free air cooling’, recapture of heat for other buildings, and even external space/environment and infrastructure constraints.

The output from the logistics and design stages allow us to identify and select a range of suitable air conditioning units. These must be right in terms of the client brief for energy efficiency and environmental factors, suitable for the project, installation spaces and meet any required Total Cost of Ownership (TCO) parameters in terms of inclusive costs for ongoing maintenance.

Air conditioning sizing is of course directly related to room size and the area that requires cooling. Most environments for IT equipment will require an ambient of around 20-25oC and for when looking at the floor area typical calculation would be to achieve 130W of cooling per m2.

Within a datacentre or server room environment the height of the room to be cooled should also be taken into consideration as this will affect the volume of air to be cooled and distributed. Other factors that need to be built into the design of an air conditioning system for a computer room is the potential for IT upgrades. The more powerful the servers the more heat they will generate. The heat within a sever room can also be affected by the materials used for walls and doors, suspended ceilings and raised access floors. All these will impact the thermodynamic characteristics the room and how heat and cool air is circulated and exchanged. As important is the lighting used. Modern LED lighting is very efficient but only lighting strips can be less so, leading to unwanted heat being generated.

Most server rooms and datacentres have a low occupancy rate. It is rare to find people within the IT space and if they are there it is for a particular work program or inspection. However, the more people in a room at any one time, the more thought has to be given to heat and humidity rise. The position of the building can also affect this aspect, especially if the building is subject to solar gain.

So the survey and project investigation puts Server Room Environments into a good position to advise our client on the right air conditioning system for their particular building or room. Whilst most people would think to finish at this stage, the actual process has several other steps including physical size and space and electrical works.

There are several different types of air conditioning system, with each type suitable for a range of environments. The simplest and lowest-cost is a wall-mounted system which is typically found in IT facilities, server rooms, computer rooms and small offices. Some single-split units can be used to cool or heat an office and whichever the operation will require venting to the outside world.

In a datacentre environment which is larger and more complex by default, more complex and expensive systems will probably be installed consisting of a number of indoor CRACs (computer room air conditioners) or CRAHs (computer room air handlers) and outdoor units such as heat exchangers and cooling towers. In door plant rooms may also house chillers. Deciding on where to place these units will depend on the use of ceiling and under floor voids, and the use of hot-aisle and cold aisle containment. Another type of server cabinet cooling system is a detachable cooling door that can be placed onto the rear of a rack cabinet.

Where internal and external cooling components and units are to be installed their actual positions relative to each other also has to be reviewed. The greater the distance the more expensive the installation will be in terms of cabling and routing electrical works and piping. The distances involved will also have to be within manufacturer’s unit specifications in order to optimise cooling performance.

Whilst we are a principle supplier of air conditioning units we also provide a consultancy and design service using the above methodology to a range of clients, partners and suppliers including building architects and design consultants and electrical contractors.

Server Room Environments also provides an efficiency audit service to assess currently installed air conditioning units and recommend upgrade paths to improve energy usage and Total Costs of Ownership (TCO). Our air conditioner maintenance engineering team is used to working with the majority of brands in the cooling market and provide maintenance contracts and response support to a number of varied installations.

Energy efficiency and Total Costs of Ownership are now high on most IT budget agendas. Not only can an upgrade to a new air conditioner improve energy efficiency but it can also reduce carbon emissions and contribute towards an organisation’s environmental management and corporate social responsibility policies.

Once the decision has been made to purchase an air conditioning system, a major ongoing costs is maintenance. Many systems include more firmware these days to assist diagnostics should an alarm or fault condition occur, either onsite or remotely. The air conditioning systems we supply are industry leading and with minimal maintenance and self-cleaning filters where possible. For mission critical IT environments, response times can be critical and at Server Room Environments we provide a complete 24/7 technical support and call-put facility for our cooling maintenance contract clients.

The efficiency and aesthetics of an air conditioning installation is important to use and our clients. We ensure that we select the right cooling system components for the application, building and surrounding area. This means reviewing structural characteristics for the building including electrical distribution, plumbing requirements, wall and room construction and even external venting with units mounted externally on concrete plinths or via brackets mounted onto walls or rooftops. Furthermore we ensure that external installations are secure from tampering and theft.

Please contact Server Room Environments for further information on our air conditioning design process and let us know how we can help you to lower your cooling costs and upgrade to the latest energy efficient systems.