More and more data centers are being constructed and commissioned to keep up with the growing boom of internet data. However, older aging data centers are increasingly requiring routine maintenance to sustain process operations. So what to do when a building’s vital cooling system must go offline in order to facilitate construction needs or maintenance/repair issues? Many data center operators are turning to rental HVAC solutions for their plan B.

Data center temperatures exceeding optimal levels can lead to huge problems for the hardware within the building. Allowing this hardware to get too hot can lead to shutdowns and downtime, which means clients can’t get the service that they have paid for. HVAC equipment providers can get chillers, cooling towers, and air conditioners into place very quickly to meet immediate data center cooling system requirements. In many situations, these engineered HVAC solutions also help data center managers improve their balance sheet by avoiding high-cost capital expenditure (CAPEX) commitments on short- to mid-term duration needs.

When considering a cooling system, it is important to work with a provider that understands how to engineer a system that seamlessly ties into the existing cooling process and can match equipment specific to the environmental demand. Each data center cooling system is unique and has different needs should, for example, they be water cooled or air cooled — there is no such thing as one-size fits all.

Following are three examples of how data center managers successfully leveraged HVAC solutions to keep their systems online and avoid unnecessary expenditures when mandatory repairs were needed.

STAYING IN THE BLACK

For one major information service provider’s data center, a facility which processes hundreds of thousands of key business and retail transactions hourly, every 10 minutes of downtime equated to a potential loss of more than $200 million. The facility was preparing for an upgrade and needed a solution to support its operations during the outage.

The project timeline was both tight and vitally important encompassing Thanksgiving through Black Friday. The work would need to be performed while no one was present during data center operations, which was also the kickoff to holiday shopping season and peak transactions during the outage would be highly undesirable, and would likely create nationwide notoriety for the customer.

The existing cooling system needed to be shut down in order to increase capacity for an expansion. The customer worked with an HVAC expert to design a system that could match its current needs plus handle the increased load — delivering 1,600 tons of cooling and a high degree of redundancy.

The solution incorporated three 1,000-ton chillers, three 1,000-ton cooling towers, and three 1,250 kW generators. A standby system was set up so that in the event of a failure, technicians could change out any piece of equipment in a matter of minutes. The custom design proved successful, and ensured the non-stop availability of the facility’s operations while delivering foolproof contingency backup.

The data center cooling solution was able to successfully and smoothly operate without interruption throughout the two-week project and ensure maximum uptime and no monetary losses.

COOL CREDIT

The housing center for a nationally recognized credit card processor needed to perform long overdue maintenance on the cooling water tower that supported the building’s data center cooling system.

The system consisted of six 100-ton Liebert room air conditioners that cooled air to and from the servers that processed credit card transactions from around the nation. These Liebert units were then cooled with a recirculating glycol solution that released its heat to a series of air condensers located on the 13th floor, plus a cooling tower located at ground level. The project started as a normal maintenance repair project, but unexpected problems with the building equipment necessitated installation of the rental equipment on an accelerated basis.

Engineers from a third-party HVAC provider determined the heat being lost from the cooling tower repair could be replaced by a system that circulated water through an exchanger that was added to the circuit as shown in the diagram. The engineers installed a plate and frame heat exchanger at ground level with a 700-sq- ft surface area. They also installed a 500-ton cooling tower with a 2,500 gallon per minute (gpm) cooling tower circulating pump to remove the heat picked up by the exchanger.

Complications arose due to a variety of factors caused by the building’s current glycol circulating pump, which was not adequate. The HVAC provider supplied an additional glycol booster circulating pump of 750 gpm so the total pump capacity could generate enough head pressure to circulate the glycol solution to the dry coolers located on the 13th floor.

As the installation proceeded it became obvious that one exchanger was not enough and that a second plate and frame exchanger would be needed. Thus, another exchanger was installed in parallel with the current exchanger.

The building data center continued in operation during maintenance of the cooling tower and allowed them to continue processing credit card transactions as normal. Building engineers were pleased with the performance of the system and had indicated that the closed loop cooling water was 5^oF cooler than that achieved by the first exchanger. They were also impressed with the fact that the condenser head pressure on the data center chillers was significantly reduced such that they were able to turn off one of the six Liebert room air conditioners.

CLIMATE-CONTROLLED CONSTRUCTION

Data centers create a heavy demand for power, cooling, and environmental control — not just when the thousands of servers inside begin pouring out heat, but right from the beginning of construction itself.

And with earnings of $1 million an hour once completed, construction by mechanical contracting firm BKI Bachelor and Kimble of one particular data center would have to be non-stop and without delays.

That meant that once construction began the BKI contractors would have to build throughout the seasons and in all weather conditions to meet a challenging deadline.

BKI at first tried to rely on their roster of rental companies who supported building projects but soon realized that the pace of construction was making managing and operating the array of equipment a complex and full-time job.

What they needed was a single contractor with extensive building and construction experience to solve the pressing problems and tackle obstacles so work could continue unhindered.

BKI secured a third-party HVAC expert to provide comfort heating for workers during the winter, but as well as heaters, the company also provided and managed generators to power the equipment rather than draw on the site’s primary power source.

This ensured maximum efficiency and minimum downtime. The technicians then showed BKI that bringing in additional heaters would also help properly cure poured concrete sooner and shave nearly three weeks off the typical curing time.

Throughout the winter, the HVAC expert brought in more power, heaters, and technicians, eventually running 12 120 kW generators to heat 1,000,000 sq ft of raw building space.

As the seasons warmed and construction phases changed, heating equipment was swapped out with cooling units to provide climate comfort support. The company delivered and ran heavy-duty HVAC units, spot coolers, and dehumidifiers to keep critical areas such as test rooms, battery rooms, and control centers, at a consistent, moisture-free 55°F, which provides optimum building conditions.

Then at the height of summer, a new and critical problem threatened to shut down construction — the site’s main cooling tower failed, resulting in water reaching 103^oF — too hot and dangerous for workers onsite and damaging for pipes. Technicians were immediately deployed to plan and implement a chilling package that quickly brought the water to a safe resting temperature of 88°F.

Being onsite and working shoulder-to-shoulder with BKI on the data center project, the HVAC provider was able to identify time- and cost-saving opportunities that eventually trimmed a month from the tight schedule and saved the firm $100,000.

CONCLUSION

The applications described in this article are just a couple of examples of how HVAC solutions help mitigate operational downtime and costs associated with data center equipment repair and maintenance. However, the ultimate benefit of these installations can only be realized by partnering with a provider with the right technical, design, and project management expertise to engineer a customized cooling solution.