Data centers are mission-critical environments where vital electronic components must stay cool. But, at some point, whether it’s caused by a loss of power, mechanical failure, or planned maintenance, the main cooling system is likely to malfunction.
In these instances, portable cooling units serve as admirable solutions to restore cooling.
“When it comes to electronic equipment, such as computers and servers, heat is the enemy,” said Garth Tagge, national sales manager, Spot Coolers. “They cannot operate reliably or continuously in an environment that is not temperature-controlled.”
To beat the heat, portable a/c units can offer reliable, around-the-clock operation to maintain a conditioned environment and prevent downtime in small- and medium-sized data centers, Tagge explained.
There are a variety of reasons contractors and data center managers turn to portable cooling. Tagge pointed out that portable units are just that — portable, which makes them simple and quick to deploy. Other features that make portable units popular with data centers are their low equipment cost and relatively small footprint, he added.
According to David Keller, sales manager, MovinCool/Denso, portable units are generally used for primary or supplemental cooling in equipment closets and for emergency backup in server rooms.
“Portable air conditioners help data center managers prevent reduced equipment life and hardware damage while improving reliability and network speed,” Keller said.
Portables also come in handy when temperatures spike or maintenance is needed.
“Our portable units augment the current HVAC equipment during periods of time when the existing system can’t maintain adequate cooling temps, especially when there is a heatwave or permanently installed units are being worked on,” said Greg Peery, national sales manager, United CoolAir Corp.
Plus, Peery noted, “renting portable units is much cheaper than installing a permanent system to solve a temporary cooling issue.”
However, ensuring the temporary problem is solved requires the right mindset. Contractors and data center managers need to be informed of how portable cooling units function and know how to apply them properly.
For instance, Tagge said customers frequently expect a 5-ton rental unit to provide the same performance as a 5-ton rooftop unit that has just failed.
“Rentals are meant to be a band-aid, an interim solution for primary a/c unit failure or shutdown,” he said. “While the cooling capacity of a 5-ton portable is identical to a 5-ton permanently installed system, a 5-ton portable cannot be quickly installed to distribute that capacity evenly throughout the space like a permanent system. As such, temperature levels within the space may not be even or brought down to pre-failure levels throughout the space.”
Instead of expecting similar performance, Tagge said that customers renting portable units should be looking for “the fastest and easiest means to gain some level of relief until permanent cooling is restored.”
Greg Crumpton, vice president of mission-critical environments for ServiceLogic in Charlotte, North Carolina, also discussed the need to understand how to apply portable units.
“Portables work great when you understand the ramifications of how to apply them,” he said. To illustrate the importance of this, Crumpton described a common scenario that can occur when a portable unit’s hot air is not properly discharged.
“Usually in a commercial building or in a data center, the hot condenser discharge air is ducted up into the ceiling plenums,” Crumpton said.
While this may seem fine at 2 o’clock in the afternoon, and the portable unit may be functioning well, there may be trouble later that night, he said.
As long as the base-building HVAC system is running, it should be “sucking that heat out of the plenum and discharging it into the building cooling system,” Crumpton said. But once everyone has gone home, that heat buildup within the plenum can lead to escalating problems.
“At 7:30 at night, once the air conditioner for the building has cut off, now you’ll get this static heat buildup in the plenum,” he explained. “What happens is the little spot cooler can’t overcome that heat, so it trips on a high head pressure, and then all the catastrophic stuff happens. The air conditioner quits, the computer room gets hot again, the a/c guy who put it in there gets a black eye, and the data center guy gets in trouble with the CIO [chief information officer] because he let the room overheat.”
However, Crumpton said, these problems can all be avoided with a good plan.
“There are ways to overcome this situation if you’re knowledgeable about the building,” he said. “You can work with the building manager to say, ‘Hey, we need to run the base building air overnight to keep this air moving so the portable air conditioner doesn’t shut off.’”
Other options include discharging the hot air through a window or using a water-cooled portable unit, Crumpton added. Overall, he said, “Portables are good as long as they’re applied properly with a well-thought-out plan.”
A good plan is also one of the keys to using portables in emergencies.
“You’re going to have a failure, no doubt. So, what are you prepared to do?” Crumpton asked. He recommends that contractors work with data center customers to establish a standard operating procedure (SOP) for emergency cooling.
With an SOP in place, data center managers can prevent interruption of mission-critical operations when a failure happens. The SOP should include details about how portable units will be used in an emergency, Crumpton said. This includes knowing where portable units will be placed, how they will be wired, and how the heat will be rejected. When an emergency situation occurs, portable units can then be used to prevent catastrophic conditions inside a data center.
“Portable cooling units provide data center managers the peace of mind against costly system downtime and the potential loss of data due to an unexpected shutdown of their main a/c system,” Keller said. “Our portable products essentially provide an inexpensive insurance policy against downtime and data loss.”
But peace of mind is only possible when contractors and data centers share a proactive approach, said Tagge.
“Don’t wait until you have a cooling unit failure or some other need before you find a portable vendor in your area,” he said. “Most portable a/c applications are a result of a/c unit failure or some other emergency. That’s not the best time to begin searching for a vendor to solve your problem. A more proactive approach — lining up a reliable supplier in advance — will serve you better if and when a problem occurs.”
Tagge explained that Spot Coolers spends a lot of time meeting with contractors and facility managers to set up accounts and approve credit in advance of a need.
“Many are happy they did the upfront due diligence, should an event occur that requires our services,” he said.
Publication date: 6/27/2016