Micro data centers keep IT departments connected to computing

As more companies move their data processing and computing to the cloud or co-location centers, some still want to maintain IT centers that are main distribution facilities (MDFs), “points of presence for their IT departments,” says Robert Sty, SmithGroup JJR’s Mission Critical Studio Leader.

Over the past two years, SmithGroup has been getting more requests from clients for micro data centers that provide that presence. One such facility is a 2,500-sf data center inside a two-story, 60,000-sf commercial office building in the Phoenix area, whose construction was completed last May.

Sty requested that the names of the client, the general contractor, and the designer of the building be withheld. But he did confess that this data center was “kind of an afterthought,” as it was being planned while the building was under construction. 

The micro data center holds 32 server cabinets, supporting mechanical and electrical equipment (N+1 configuration), a shipping/receiving area, and an IT lab for build/burn-in testing for servers.

“It was like putting 10 pounds in a five-pound bag,” he says. To make this work, SmithGroup JJR raised the cabinet density to 7kW per unit. “But that created a heat load,” says Sty, which would be problematic if the cooling system went down. 

The solution was to install a battery-powered flywheel backup uninterruptible power supply (UPS) onto the computer room air conditioner so the fans would keep circulating air during a power failure.

SmithGroup also deployed hot-aisle containment, a method of cooling that uses a physical barrier to guide hot exhaust airflow from server racks back to the AC return. It cools the front and back of the aisles, and mwwaintains an average room temperature of 70-75ºF.

Sty says that any client whose IT group asks for a micro data center that never goes down needs to appreciate that offices and other nonresidential spaces don’t always have the necessary infrastructure, such as a second utility feed or centralized cooling plant. Floors under data centers need to be able to handle at least 150 pounds per sf, compared to the 50-100 psf that offices are built to support. (The Phoenix office was designed to carry the heavier load.)

Data centers, regardless of size, take up more space than most clients realize. “We had to get real tight” with the mechanical and electrical equipment to keep it off of the data center floor, says Sty. 

So far, the client’s feedback has been positive. Phoenix had an unusually hot summer, with outdoor temperatures rising as high as 117ºF. But the data center “has been holding the temperature to where it’s easy enough to work around,” says Sty. And the clearances proved to be satisfactory, even with larger cabinets.