Understanding ASHRAE Data Center Temperature & Humidity Guidelines

Infrastructure is everywhere, and data centers are at the heart of modern-day society. They house computer systems and associated components such as telecommunications and storage systems. Therefore, understanding ASHRAE data center temperature and humidity guidelines for built environments is critical to the success of any data center. So, let’s talk about what they are and why these are important to understand.

Quick Recap: What is ASHRAE?

The American Society of Heating, Refrigerating and Air-Conditioning Engineers is a global society advancing sustainable technology for built environments. The Society and its members focus on building systems, energy efficiency, IAQ, refrigeration, and sustainability within the industry. ASHRAE standardizes today’s built environment through research, writing, publishing, and continuing education.

This was born from the merging of the American Society of Heating and Air-Conditioning Engineers (ASHAE) and the American Society of Refrigerating Engineers (ASRE). In 2012, they started using the abbreviation ASHRAE instead of the full name. They are internationally recognized for their standards and guidelines related to HVAC systems. The standards they set are often reflected in new building codes set forth by engineers, contractors, and government agencies.

Breakdown of ASHRAE Data Center Recommendations

ASHRAE developed what is known as ASHRAE 90.4. This new standard recommends data centers effectively monitor temperature and humidity levels to reduce downtime and enhance efficiencies.

Their recommendation requirements are:

  • The minimum temperature is 15°C.
  • The maximum temperature is 32°C.
  • The minimum Relative Humidity (RH) is 20%.
  • The maximum RH is 80%.
  • The maximum dew point is 22°C.
  • The rate of change of temperature is less than 5°C/h.
  • The rate of change of humidity is less than 5% RH per hour, and no condensation.

According to ASHRAE Standard 52.2, they are also recommending best practices for keeping data center air clean. The MERV 8 filters trap 70% of particles 3.0 microns and larger. Some data centers will use MERV 11 filters because these trap up to 80% of particles 1.0 microns and larger.

These recommendations aim to prevent ESD (Electrostatic Discharge), prolong the life expectancy of equipment, and lower the risk of corrosion due to excessive condensation. ESD happens when two objects come into contact and release static electricity. Why is this important? ESD can destroy or damage sensitive electronic components, erase or alter magnetic media, or set off explosions or fires in some environments.

How to Achieve the Recommendations?

Current data centers have unique challenges, as you can imagine. The most obvious is that the electrical equipment produces considerable heat. In turn, this increases humidity, and continuous air cleaning is necessary. However, HVAC systems specific to data centers, called Computer Room Air Conditioners (CRAC), help eradicate these challenges.

What is CRAC?

Data centers’ HVAC systems will always be separate from the central building HVAC systems. Instead, they have CRAC units and fire suppression systems. The CRAC unit is an HVAC system that controls room temperature and humidity and has robust air filters. Microprocessors of CRAC units will monitor room conditions and adjust to keep data centers at the recommended standards. If there is a complete failure of these units, centers with alarms for immediate expert intervention.

  • The cooling mode of the CRAC is controlled by the rise of temperature above the set point of the room; as the temperature decreases to the appropriate set point plus the dead band, the cooling mode will deactivate.
  • Humidifier mode is activated when the relative humidity in the space drops to the set point minus the dead band. As the moisture returns to the set point, the humidifier on the unit deactivates.
  • CRAC units have filters to assist with removing debris particles

ASHRAE data center guidelines also suggest installing temperature and humidity sensors. This helps to monitor levels throughout the room and at individual servers. As part of best practices, you should also install intelligent PDU sensors. These provide real-time alerts and remote on/off abilities. These intelligent PDUs offer extra protection for data center management and mitigate environmental and cost risks.

Contact Us for Your Data Center HVAC Needs

The Severn Group is extremely knowledgeable about data center HVAC. We know that CRAC units require regular maintenance. Because these units operate 24/7, regular inspections and cleanings are necessary. In addition, CRAC systems are critical to data centers’ downtime, which can wreak havoc on customers’ bottom line.

The Severn Group provides contracting and HVAC services, specializing in business interiors, build-outs, renovation, and rehabilitation. In addition, our team trains and reviews industry standards for commercial HVAC systems, government institution facilities, hospitals, and data centers. Call us today about our services and maintenance contracts for your HVAC needs.