GEA

Claiming that it offers indirect free cooling in combination with adiabatic humidification, GEA presented its new GEA Adia-DENCO cooling system at Chillventa 2012. Announcing this, the company said that the system, which has been especially developed for climate control of computer centres, is based on the design of the proven GEA CAIR air-handling units.

GEA explains its working: The adiabatic cooling system is based on the principle that evaporating water removes heat from its surroundings. Cooling takes place in a large double-plate heat exchanger. The warm outdoor air is first humidified, which cools it, and is then sent to dual recuperator, which then cools the entering warm return air from the computer centre by hermetically sealed heat exchange.

The manufacturer lists the following product features and advantages:

• It offers rated air flow of 25,000 m³/h with cooling duty of 100 kW.
• The extremely low annual operating costs of the cooling system enable its amortisation after a short period at computer centres.
• At outdoor temperatures under 6°C, the indirect free cooling alone of the Adia-DENCO is sufficient to completely extract the thermal load produced. At this operating point, all additional cooling sources (adiabatic sources as well as compression-refrigeration cooling) are switched off.
• The highly efficient EC fans in the outside-air flow operate at their minimum speed and assure that the temperature of the supply air for the computer centre does not exceed 25°C.
• At outdoor temperatures between 6°C and 22°C, it suffices to control only the EC fans steplessly up to their maximum speed level. It is only at temperatures above 22°C that adiabatic cooling is required.
• The integrated open-and closed-loop control system finds the energetic minimum here between the fan output and the required adiabatic cooling.
• Depending on the output demand from the computer centre and at outdoor temperatures of over 29°C the adiabatic cooling system is supported by an additional peak-load cooler.
• As an option, it can be designed for 100% cooling duty for purposes of redundancy.
• It satisfies the new environmental recommendations for computer centres, which advise maximum supply-air temperatures of 27°C.