Monitoring Data Centers: Temperature, Humidity and Dew Point

Physical environment factors such as temperature and humidity are often ignored when it comes to monitoring server rooms. Small variations in these factors can cause major disruption in services, and are therefore critical to the smooth and safe operations of data centers.

Monitoring Data Centers: Temperature, Humidity and Dew PointOne important metric for server rooms is the dew point. Dew point is the temperature at which the water vapor in the atmosphere condenses to liquid. This can be dangerous since water droplets will start appearing in the physical environment at this temperature. If this happens there is a risk of corrosion to the equipment and hence temperature below dew point needs to be avoided. Dew point is derived out of both temperature and humidity. For example, if the temperature is 68 degree fahrenheit and the humidity is at fifty percent, then the dew point will be at 48.6 degrees.

The allowable range for dew point as per theASHRAE standards is between the limits of 5.5°C (41.9°F) and 15°C (59°F). Other measures are the maximum operating temperature for the CPU, which should be restricted to 40°C (104 F). An overheated CPU can lead to frequent system shut downs and also small calculation errors that are hard to catch and detect. Only when the errors become significant and after considerable analysis can the problem be rooted down to an unsuitable temperature for efficient CPU operations.

Humidity is an important factor to consider also when it comes to server rooms. Unlike temperature, this is a less visible factor and the impact is lesser known. A humidity higher than 60% can lead to corrosion of the equipment. A humidity lower than 40% can lead to electro static build up and discharge (ESD). ESD can be very harmful for devices such as NEMS (nano electro mechanical systems) and MEMS (micro electro magnetic systems) as a small static discharge can permanently damage these systems. IEC 61340-5-1 is an international standard that publishes the requirements for ESD control programs. Facilities can also get themselves certified and assessed so that they are compliant in the handling of ESD sensitive devices.

The truth is that the physical environment matters just as much as the capacity of the servers and the sophisticated management and monitoring tools that you bring into the datacenter. Why take chances on some simple changes that you can bring about in your server environments? To get the best advice on data center environments, visit and contact us for best practices on managing data centers.

Alex Carroll

Alex Carroll

Managing Member at Lifeline Data Centers
Alex, co-owner, is responsible for all real estate, construction and mission critical facilities: hardened buildings, power systems, cooling systems, fire suppression, and environmentals. Alex also manages relationships with the telecommunications providers and has an extensive background in IT infrastructure support, database administration and software design and development. Alex architected Lifeline’s proprietary GRCA system and is hands-on every day in the data center.