What does a traditional data center cooling environment look like? Uptime Institute has this definition: "cold air from a computer room air conditioner (CRAC) or computer room air handler (CRAH) pressurized the space below the raised floor. Perforated tiles provided a means for the cold air to leave the plenum and enter the main space—ideally in front of server intakes. After passing through the server, the heated air returned to the CRAC/CRAH to be cooled, usually after mixing with the cold air. Very often, the CRAC unit's return temperature was the set point used to control the cooling system's operation."

With the 24/7/365 requirement for the cooling equipment to keep today's IT investments at ideal temperatures and safe from overheating, these solutions have a wide range of design and intent, from simple to sophisticated.

Data center cooling solutions

Some highlights of the most common cooling methods:

  • Air-based cooling is the most common and least efficient, allowing cold and hot air to mix.
  • Cold / Hot Aisle Containment, adding to air-based will increase the efficiencies and reduce hot spots and air mixing.
  • In-row cooling that is close coupled with the IT racks to consume hot discharge air at its warmest and the fastest.
  • Liquid-Based
    • Immersion: Submerging the IT hardware into a tub of non-conductive, non-flammable dielectric fluid.
    • Direct to Chip: Dielectric fluid direct to the cold-plate above the microprocessor.

So, what are some ideal operating cooling parameters? The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) recommends that server inlet temperatures are between 18 and 27 degrees Celsius (64.4 to 80.6 degrees Fahrenheit), with relative humidity anywhere between 20 and 80 percent in the TC9.9 Guidelines.

The Uptime Institute recommends a slightly different set of parameters, with the upper limit of 25 degrees C (77 degrees F).

The Severn Group reports the perfect range is between "73 and 75 degrees Fahrenheit."

Let's go back to the original Network Equipment-Building System (NEBS), which ironically are the same temperature recommendations that ASHRAE now recommends, except for the shocking humidity allowable range of 5%-85%RH.

Cooling has a long-tested history and is a proven technology however there are many ways to approach a cooling solution that are right for your data center or edge environment in addition to the numerous parameters available to tune it efficiently. So what does it mean to match cooling capacity? This concept is to evaluate the heat in the system, target cooling as directly as possible at the problem and use the most efficient cooling strategies for that space.

To learn more about these and other cooling methods that might support your IT investment or align with the business goals, please reach out to our FIT practice and/or schedule a workshop or briefing.