The increasing power of processors and widespread use of densely-packed systems such as blade servers means increasing energy consumption and high levels of waste heat generated in confined spaces. An adequate but also efficient cooling capacity is becoming a must. For such high cooling requirements Schroff is now offering a new cooling solution with its Varistar LHX 40 as an optimally-matched complete cabinet solution.

The new air/water heat exchanger is capable of removing up to 40 kW of waste heat per cabinet. The heat exchanger has a closed air loop with an airflow capacity of up to 4200 m3/h. The exhaust temperature available to the servers can be adjusted in 0.1 degree increments from 18 to 30 °C. Mounted laterally to right or left in a 1200 mm deep cabinet, the heat exchanger provides a homogeneous air distribution throughout the entire 19" mounting height using seven fans that can be replaced during operation, thus assuring uniform heat dissipation for all the systems installed in the cabinet. Fixed connectors on the rear of the fan modules make the modules quick and simple to replace when necessary. The fans blow the cold air directly onto the installed components from one side. With the width of the air/water heat exchanger being only 200 mm, an 800 mm wide cabinet is sufficient for this cooling solution. The result is a reduced space requirement in the data centre compared to similar systems on the market.

A droplet separator is included to prevent condensation from collecting inside the cabinet. Water and power are connected from below. The water connection to the air/water heat exchanger can be to either the front or the rear of the unit. Loss of pressure on the water side of the LHX 40 is very low, under 0.5 bar.

Interfaces mounted on the rear of the unit (prepared for RS 232, RJ 45, RS 485 and Ethernet) for alarm outputs and warning signals, for external cabinet control systems or for system monitoring with AdvancedTCA shelf management, assure uninterrupted operation. A display on the front of the heat exchanger shows all operating conditions and values. By adjusting the air/water heat exchanger, the cooling capacity can be matched exactly to the specific requirements of the customer or application. This also ensures high energy efficiency in cooling and minimised operating costs to the customer.

Users who currently have versions of the LHX 20 in operation but now require greater cooling, may simply swap the LHX 20 module for that of the LHX 40 and immediately enjoy doubled cooling capacity. It can thus be seen that the same cabinet platform offers a highly scaleable solution.

To increase the failure safety of the cooling in the cabinet it is recommended that a redundant power supply be provided for the supply network. For this purpose Schroff's tried and tested AC changeover module, for universal cabinet mounting, offers a lower-cost alternative to a UPS (uninterruptible power supply). The module acts as an electronic switch that changes between two supply mains (the primary and secondary networks). If the primary mains cuts out for more than 10 ms, the device switches over to the second input and thus onto the emergency supply network. The total changeover time is less than 20 ms.