Along with helping our customers with all things IT, here at Carousel Industries we are focused on staying on the cutting edge and creating best practices within our own physical infrastructure and data center. Lately much of that job falls upon Derek Herard, a convergence technician in our Rhode Island headquarters.
After 10 years as a field technician, about 2 years ago Derek started working inside Carousel’s offices, doing everything from building cubicles to running cabling and building out the demo room at headquarters. Along with the rest of the Carousel support group, he helps maintain facilities such as HVAC and power, and work on internal projects.
One Warm Server Room
One such project cropped up back in 2010, when it was getting mighty warm in the Carousel server room. “We were using the building HVAC system to cool the room, the rooftop unit that’s really made for providing comfort air for the offices,” Herard says. “In the server room it was on full blast all the time and it was never below 82 degrees.”
Even worse, the temperature would fluctuate dramatically, by about 10 degrees every minute. When the room warmed up, the HVAC would crank up, going full bore until the temperature hit what the thermostat was set at. But it would stay there only a short time before the heat coming from the servers cranked it right back up again.
That constant on/off cycling is of course not good for the health of the HVAC system – nor for the power bill.
In-Row Cooling: A Cure for Overheated Data Centers
Around that time Carousel had just learned about in-row cooling systems from its partner APC by Schneider Electric. As the name implies, such systems involve installing cooling units in the same rows of racks that house the IT equipment it is intended to cool.
“The cooling units are the same size as our data racks, taking up one 2-foot wide space in the rack,” Herard says. And they’re the same height as the server cabinets, about 7 feet tall.
The idea behind in-row cooling is to dramatically reduce the distance the cool air has to travel to reach the IT equipment it is intended to cool, thus making it far more efficient vs. having the air travel long distances through air ducts.
Best Practices: Download the free whitepaper, “6 Keys to Saving Energy in Your Data Center”
And it works. “Now the temperature is sustained wherever we want it at all times,” Herard says. He notes the building HVAC system is no longer used to cool the server room at all. What’s more, the APC NetBotzremote monitoring system enables Herard to stay on top of what the temperature is and get an alert should it fall outside the prescribed range.
Figure 1 is a screen grab from the NetBotz system, showing the temperature in the enclosure at Rhode Island headquarters consistently hovering right around 75 degrees. Compare that to Figure 2, which shows a smaller server room at a Carousel site in Conn. that doesn’t yet have in-row cooling: it clearly shows the rapid 10-degree swings that used to plague the Rhode Island site.
Carousel actually has two in-row cooling systems, one for each of its two rows of racks. One of the systems, the APC ACRP101 DX, monitors temperatures and can control humidity as well. The other, the APC ACRD501 DX, has the same cooling capacity but no humidity control, since the other unit is sufficient to control humidity in the room.
Hot Aisle Containment Adds Further Data Center Efficiency
Not quite a year later, Carousel added a hot aisle containment system to make the setup even more efficient. It’s a standard data center best practice to configure rows such that the front of servers face each other, as do the rear. In a data center with multiple rows of racks, that creates one aisle - the “cool aisle” – where cool air can be pumped into two rows of servers at once. Similarly, the exhaust coming from two adjacent rows comes out the rear, creating a “hot aisle.”
A hot aisle containment system is basically a large metal hood that covers the hot aisle and captures the air so it doesn’t circulate back into the cool aisle. Rather, it gets pumped directly back into the cooling system. While it seems counterintuitive, it actually takes less energy to cool that warm air than it does to cool fresh, outside air.
From a cooling perspective, the hot aisle containment system basically cut the size of the server room in half, Herard says. “We’re only cooling the air that needs to be cooled for the servers, the intake air,” he notes.
And it shows in the energy bill, which Herard says has been cut in half since installation of the hot-aisle containment system.
Carousel has also replicated this approach in their on-demand labs data center. “The amount of equipment in the lab is constantly fluctuating up and down depending on the types of projects we are working on,” say Herard. “Utilizing the hot aisle containment and in-row cooling best practice in our labs has resulted in the same types of savings we’ve seen in our production data center.”
If cutting your data center energy bill sounds like a good idea, contact Carousel - we can help you identify ways to make it happen. And don’t forget to download the free whitepaper, 6 Keys to Saving Energy in Your Data Center.”