The Stack Archive

Emergency cooling – hire or buy?

Fri 26 Aug 2016

Air con commercial

carl-webbCarl Webb, UK Director (HVAC), at Andrews Sykes, discusses why it is essential for data centre managers to have a suitable approach to emergency cooling…

Since the dawn of the data centre, organisations have required air conditioning to ensure the smooth running of their servers. Heat can build up for many reasons, including a lack of air flow, heat spots caused by server positioning, the air conditioner’s ability to deal with the heat load, and inefficient air conditioning solutions.

Usually, businesses will have a secondary air conditioning supply in place to avoid dreaded downtime experienced when servers shut down due to the rising temperature. This is especially true for commercial data centres, which are processing millions of pounds’ worth of transactions each day from across the globe.

However, what if an organisation’s backup solution was also to fail? The availability of emergency air conditioning is non-negotiable, especially when downtime will usually result in a great deal of lost revenue.


When considering whether to hire or buy an emergency air conditioning unit, it largely comes down to considering capital expenditure versus operational expenditure. Hiring a unit will result in an operational cost, whilst purchasing an air conditioning solution will become a capital expenditure, each with their own set of benefits and challenges.


The cost of buying an air conditioner can be perceived as more cost-effective than hiring one. However, there are a number of things that can be overlooked in this analysis.

Although purchasing an air conditioning unit is a one-off cost, expenses such as the ongoing maintenance required and the potential cost of parts can soon add up. It is also worth considering the efficiency of newer units compared to ageing units. This tends to be especially applicable when it comes to large chiller units, which are most suitable for sizable data centres with very high heat loads. When assessing the efficiency of an ageing chiller unit compared to a newer unit, and depending on its condition, the difference in weekly running costs can be as much as £700. Typically this is due to the advances in efficiencies of components and compressors.

Even with smaller portable units, the initial outlay and the cost of maintenance can often cost more than hiring a unit for the same period.

Tax break

In some cases, businesses may be eligible for Enhanced Capital Allowances (ECAs), which aim to improve a business’ cash flow through accelerated tax relief. This tends to be available on energy saving air conditioning purchases.

Screen Shot 2016-08-26 at 09.27.16Immediate access

As with all emergency situations, speed is key. Having a solution on-site is a major benefit of purchasing a unit, however, some suppliers are in fact able to deliver a solution on-site within as little as four hours. By appointing a specialist supplier, this will not only ensure you have the most appropriate solution for the job, it will also be expertly installed and positioned for maximum efficiency.

If the data centre in question is a large-scale operation, having a number of portable units to hand may not be suitable for the heat load, which requires cooling. Instead, a large chiller unit capable of supplying large quantities of cool air should be opted for. It would be very difficult to store this type of unit on-site given its size, taking up valuable square footage, and is therefore best used on a hire basis.

For smaller air conditioning units, storage is also a key consideration as storing a unit correctly can extend its life and efficiency. Before storing the unit, ensure all moisture from inside the unit is drained and then place it under a cover to protect it from gathering dirt and dust. It must then be stored in a cool, dry place.


Air conditioning units are relatively robust and can last a long time if they are well maintained. Key factors impacting on efficiency that are often overlooked include the regular dusting of coils and cleaning of the filters. If the filters aren’t cleaned, they can clog resulting in air being unable to pass through to be cooled.

Despite the purchase of an air conditioning unit providing instant access, as the years tick by, technological advances will enter the marketplace, increasing efficiency and capability.

The future

With the emergence of Artificial Intelligence (AI), the future of data centre management could become increasingly machine operated. Although human interaction will be required in the initial phases to support and provide opportunities for machine learning, AI will certainly have a greater role in maintaining data centre environments.

This is already the case with Google, having recently announced that the company has been able to cut its total data centre energy use by 15% with the use of machine learning. The software allows for precision management of data centre conditions, flagging and pre-empting any deviations in temperature, humidity or pressure before they have even occurred.

For now, whilst the pressure is firmly on data centre managers to maintain the data centre environment, it is essential to have considered a suitable approach to emergency cooling, whether you opt to hire or buy.


cooling Data Centre feature Heating Ventilation and Air-Conditioning (HVAC)
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