Could your DC benefit from internal evaporative coolers?

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EcoCooling’s managing director Alan Beresford explains the drivers behind the development of the new range of internal evaporative cooling systems and discuss how the design has been re-configured to suit the installation requirements of data centres.

ecocooling1EcoCoolers are made by EcoCooling, an evaporative cooling company with over 370 data centre installations, and 200 telecoms installations throughout the UK and abroad. Its product ranges incorporate energy efficient direct evaporative cooling and free cooling/ventilation and have resulted in substantial savings being achieved in data centres using their cooling systems in place of standard computer room refrigeration systems (CRACS).

In most installations the energy use of a ventilation system, supplemented by direct evaporative cooling on warm days, uses less than 10% of the electricity of a conventional DX refrigeration system found in many data centres.  Typically using 5kW or less per 100kW of IT cooling load this enables data centres, with reasonably efficient UPS’s and other infrastructure, to potentially achieve a PUE of less than 1.1.

This level of performance is obviously attractive to many data centre operators but, until now, installations involving internal plant and equipment, was not possible.  The development of the internal system overcomes this and opens up a new market for this energy efficient cooling system.

The ECT range is different from the standard ECP cooler as its design has been derived from a specification given by the largest telecommunications server in the UK, who wanted the savings associated with evaporative cooling systems but needed internal cooling units that were secure, easy to maintain and could be installed quickly on a large scale.  Amongst the list of benefits associated with the internal cooler is the single box requirement, the ECT unit contains the evaporative cooling element, control system, supply fan and recirculation damper, reducing installation costs significantly.

Those likely to benefit most from a more compact unit are existing data centres. While most people do not have the luxury of building a new data centre from the ground up, they do have the challenge of improving existing ones. The drive for energy efficiency is relentless, and operating costs or external drivers, such as government targets or ESOS surveys, can prevent a data centre from reaching peak efficiency. Existing data centres in the public sector are being pushed to find alternatives to AC, so evaporative cooling units that can be easily retrofitted are a great solution to this problem. In many cases, the costs of retrofitting external equipment are prohibitive, and on the flip side of this problem, many end users have buildings which are not suitable for conventional ducted ventilation systems with external equipment, so an internal cooling unit is exactly what they need.

Many existing data centres often have poor layouts. The effect of this is that some of the cooled air bypasses the servers and simply circulates around the data centre.  A conventional DX CRAC in these situations becomes a very expensive fan with very poorly utilised cooling and cannot possibly operate efficiently! The EcoCooling systems are designed primarily as a ventilation system to accommodate these compromised layouts and, by careful selection of the correct Electrically Commutated fans, provide an efficient air flow solution. The EcoCooling system also retains or improves efficiency when old equipment is updated or data centres reconfigured into hot and cold aisles with containment.  This is because an EC fan becomes more efficient at slower speeds.   When air flow bypass is reduced then the fans can run slower with higher efficiency.  Reducing the fan speed by 20% reduces fan energy by 50%!

When considering retrofitting evaporative cooling it is important for end-users and stakeholders to understand and accept the humidity and temperature performance achieved using direct systems.  Many datacentre managers are wary of the effects of high temperatures and high humidity in their data centres.  Much of this concern is unwarranted as modern IT equipment is much more robust than older equipment, which required close control of both temperature and humidity.

With the progression of modern equipment, it has become less about maintaining a specific humidity, and more about not reaching the extremes. Most modern equipment will work well between 10-95% humidity. Below 10% and you run the risk of static electricity being created and above 95% you risk corrosion.  While humidity control is not normally necessary in the UK, as an evaporative cooling solution it became obvious that we should offer a humidification option in the ECT unit particularly when we started working in the Nordics, where cold temperatures and low humidity are the norm.

Our patented humidification process works by opening an additional damper to reintroduce recirculated air into the supply steam and shutting off the external air. This creates the desired humidification, but control of the supply air temperature is lost.  To counter this, we operate one EcoCooler in humidification mode alongside two EcoCoolers in normal operation.  The EcoCoolers work together to produce acceptable conditions in even the driest and coldest of climates. In our latest installation in Sweden for Hydro 66 this has prevented the formation of air containing moisture, and static electricity, which could have been extremely harmful to their electrical equipment.

While a decrease in energy use is a driver for some of our clients, lower installation costs can also be a driver for smaller organisations and facilities with limited initial load and budgets.  The simplicity of the ECT units has allowed some of our more innovative end users to complete their own installations, reducing their capital outlay and achieve the savings that are attractive from both an environmental and cost standpoint.

Join us at Data Centre World where we will be presenting a client led case study on the largest ECT installation of 2016 with Hydro66.

ecocooling.org

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