Data center environment control systems evolve
Tuesday, Jun 18th 2013

Most people are aware by now that computers and servers produce a lot of heat when operating. As NBC affiliate WHEC recently pointed out, many experts will recommend implementing air conditioning cooling systems to monitor and control server temperature. However, while many IT managers might utilize standard air conditioning solutions that moderate humidity and temperature to protect computer and server performance, there have been numerous developments in cooling system designs that bring new solutions to the forefront. Datacenter Dynamics contributor John Collins recently reviewed how data center cooling technologies and strategies continue to evolve, arguing that data center design should transform along with it.

"Driven by rising power densities and heat levels, data center cooling strategies have changed dramatically over time," Collins wrote. "Until relatively recently, most cooling schemes relied on so-called 'chaos' air distribution methodologies, in which perimeter computer room air conditioning (CRAC) units pumped out massive volumes of chilled air that both cooled IT equipment and helped push hot server exhaust air towards the facility's return air ducts."

However, Collins also noted that chaos air distribution regularly results in numerous inefficiencies, including re-circulation, bypass air and air stratification. Re-circulation is when hot exhaust air makes its way back into server air intake, which can cause server room temperature to rise to dangerous levels. Air stratification is a problem caused by air's natural tendency to gather in different temperature-based layers, leading precision cooling equipment to function at less than optimal levels. As data center managers try to resolve air stratification issues by increasing fan speed, Collins explained that this can then lead to bypass air inefficiencies. Bypass air is when the velocity of the cool air stream surpasses the server fan's ability to draw the cool air into the unit, which can  cause organizations to spend money on cooling that does not produce effective results.

Benefits of containment cooling strategies
Collins revealed that many data center managers opted for hot aisle/cold aisle strategies to combat the inefficiencies detailed above. However, this allowed for only marginal improvements to be made, causing many data center managers to look to containment solutions and environment control systems instead. According to Collins, containment cooling solutions are designed to organize air streams, sealing servers in structures that capture hot air and vent it appropriately. These cooling systems incorporate advanced temperature sensor devices that can ensure that the cooled air vented toward servers is optimally delivered directly toward air intakes.

The benefits of containment cooling strategies are wide ranging, but Collins outlined a few of the major advantages of this technology, including improved cooling efficiency and equipment reliability, reduced energy spending and greater flexibility with floor planning. Collins also noted that despite the obvious advantages of these enhanced cooling strategies, many organizations have not properly adjusted their data center design strategies and continue to first design a building and fill in the open space with server racks. This can produce problems, however, as inconveniently placed structural elements can cause air ducts to bend and become less efficient.

"As a result, companies are increasingly recognizing the wisdom of designing data centers not from the walls in but from the server rack out," Collins wrote. "Instead of building a room and then filling it with racks, they're selecting the ideal racks for their needs and designing the room around them. Instead of under or overprovisioning their new facility's power and cooling resources, they're installing the optimal infrastructure for the precise array of hardware and enclosures they'll be using. Instead of improvising solutions to efficiency-sapping structural defects, they're preventing those defects from occurring in the first place."

As Collins noted, these types of changes in approach to design have resulted in data centers that do not only operate more efficiently, but also cost less to cool and maintain. These data centers are generally more reliable and more conducive to business continuity. Server room environmental monitoring will also play an integral role in the regular operation of these more efficient data centers, as keeping an eye on changing conditions is paramount to continued results.