Over the years there has been a rapid increase in large stand-alone data centres housing computer systems, hosting cloud computing servers and supporting telecommunications equipment. These are crucial for every company for IT operations around the world.

It is paramount for manufacturers of information technology equipment (ITE) to increase computing capability and improve computing efficiency.  With an influx of data centers required to house large numbers of servers, they have become significant power consumers. All the stakeholders including ITE manufacturers, physical infrastructure manufacturers, data centers designers and operators have been focusing on reducing power consumption from the non-computing part of the overall power load: one major cost is the cooling infrastructure that supports the ITE.

Too much or too little Humidity can make one uncomfortable. Similarly, computer hardware does not like these extreme conditions any more than we do. With too much humidity, condensation can occur and with too little humidity, static electricity can occur: both can have a significant impact and can cause damage to computers and equipment in data centers.

It is therefore essential to maintain and control ideal environmental conditions, with precise humidity and temperature measurement, thus increasing energy efficiency whilst reducing energy costs in Data Centers. ASHRAE Thermal Guidelines for Data Processing Environments has helped create a framework for the industry to follow and better understand the implications of ITE cooling component.

Rotronic’s high precision, fast responding and long-term stability temperature and humidity sensors are regularly specified for monitoring and controlling conditions in data centres.

Why measure temperature and humidity?

Maintaining temperature and humidity levels in the data center can reduce unplanned downtime caused by environmental conditions and can save companies thousands or even millions of dollars per year. A recent whitepaper from The Green Grid (“Updated Air-Side Free Cooling Maps: The Impact of ASHRAE 2011 Allowable Ranges”) discusses the new ASHRAE recommended and allowable ranges in the context of free cooling.

The humidity varies to some extent with temperature, however, in a data center, the absolute humidity should never fall below 0.006 g/kg, nor should it ever exceed 0.011 g/kg.

Maintaining temperature range between 20° to 24°C is optimal for system reliability. This temperature range provides a safe buffer for equipment to operate in the event of air conditioning or HVAC equipment failure while making it easier to maintain a safe relative humidity level.  In general ITE should not be operated in a data center where the ambient room temperature has exceeded 30°C. Maintaining ambient relative humidity levels between 45% and 55% is recommended.

Additionally, data centre managers need to be alerted to  change in temperature and humidity levels.

Rotronic temperature and humidity probes with suitable transmitters or loggers are most suitable for monitoring & controlling conditions in data centres due to their high precision and fast response with long-term stability.

With Rotronic HW4 Software a separate monitoring system can be implemented. This enables data center managers to view measured values and automatically save the measured data. Alarm via email and SMS, with report printout allow data integrity guaranteed at all times.

Dr Jeremy Wingate
Rotronic UK