Recommended Data Center Temperature & Humidity

Monitoring the environment conditions in a computer room or data center is critical to ensuring uptime and system reliability. A report from the Gartner Group in late 2003 estimated that the average hourly cost of downtime for a computer network at that time was $42,000 (1,260,000 baht). In the year 2011, it has likely gone up dramatically. At these high costs, even companies with 99.9% up-time lose hundreds of thousands of dollars each year in unplanned downtime. Maintaining recommended temperature and humidity levels in the data center can reduce unplanned downtime caused by environment conditions and save companies thousands or even millions of dollars per year.

Operating expensive IT computer equipment for extended periods of time at high temperatures greatly reduces reliability, longevity of components and will likely cause unplanned downtime. Maintaining an ambient temperature range of 68° to 75°F (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.

It is a generally agreed upon standard in the computer industry that expensive IT equipment should not be operated in a computer room or data center where the ambient room temperature has exceeded 85°F (30°C).

In today’s high-density data centers and computer rooms, measuring the ambient room temperature is often not enough. The temperature of the air where it enters the server can be measurably higher than the ambient room temperature, depending on the layout of the data center and a higher concentration of heat producing equipment such as blade servers. Measuring the temperature of the aisles in the data center at multiple height levels can give an early indication of a potential temperature problem. For consistent and reliable temperature monitoring, place a temperature sensor at least every 25 feet in each aisle with sensors placed closer together if high temperature equipment like blade servers are in use. We recommend installing TemPageR, Room Alert 7E or Room Alert 11E rack units at the top of each rack in the data center. As the heat generated by the components in the rack rises, TemPageR and Room Alert units will provide an early warning and notify staff for temperature issues before critical systems, servers or network equipment is damaged.

Relative humidity (RH) is defined as the amount of moisture in the air at a given temperature in relation to the maximum amount of moisture the air could hold at the same temperature. In a data center or computer room, maintaining ambient relative humidity levels between 45% and 55% is recommended for optimal performance and reliability.

When relative humidity levels are too high, water condensation can occur which results in hardware corrosion and early system and component failure. If the relative humidity is too low, computer equipment becomes susceptible to electrostatic discharge (ESD) which can cause damage to sensitive components. When monitoring the relative humidity in the data center, we recommend early warning alerts at 40% and 60% relative humidity, with critical alerts at 30% and 70% relative humidity. It is important to remember that the relative humidity is directly related to the current temperature, so monitoring temperature and humidity together is critical. As the value of IT equipment increases, the risk and associated costs can increase exponentially.

References: AVTech.com, datacenterknowledge.com, apc.com, wikimedia.org.