What is Cold Aisle Containment?

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What is Cold Aisle Containment?

Data centers have become a very important yet seldom seen part of our daily lives. They can be defined best as facilities which maintain all of the computer systems and components of a given network. Being so important, you would be right in thinking that a lot goes into their preventative care, specifically when it comes to their environment. The first priority is the energy supply and so redundant systems are often installed as a backup power source in case of an emergency. Supplying enough power is especially important considering a large scale data center can consume as much electricity as a small town. Redundant data communications connections are another preventative measure often taken should there be an incidence of device or utility failure.

Although they are sometimes the most complex level of protection, environmental controls are probably the most important. The physical qualities of the air within a certain range are necessary to receive the optimal performance of the technology; these involve the environmental controls. At its most simple, some of these controls include things like fire alarms and suppressants or air conditioners which filter the air and help to cool it. Relatively, humidity is a major concern because of the threat it can pose to the performance of the systems so dehumidifiers are often used to control the level.

How Does Aisle Containment Work?

Both hot and cold aisle containment can improve the functionality and the efficiency of the standard control room cooling systems. While both of these methods can minimize the combining of hot with cold air, there are distinct reasons why some companies implement one over the other, depending on work environment conditions and the accessibility of systems already in place.

cold aisle containment system flow

According to a 2016 research study published by researchgate.net:

Using proper air distribution to reduce or to prevent the hot air re-circulation and/or the cold air bypass is effective and to be efficient thermal management of data centers. In practice, avoiding mixing of hot and cold air mixing is a key for efficient data center cooling strategies. Hence containment of hot-aisle or cold-aisle throughout the data center is an important thermal management and energy saving strategy.

Temperature control can be reached in many ways, one of which is refrigeration, but a frequently imposed solution is separating the hot air from the cool air as is accomplished with hot or cold aisle containment. Containment of hot and cold aisles is meant to minimize the warming effect that exhaust air may have on the server room. The main idea of hot and cold aisle containment is using something like ducting to channel away hot air from the device cabinets while pulling cool air into the server room. The cabinets, in this design, are arranged in pairs that are facing each other so that the cool air can easily reach the air intakes (cold containment) and the warm air is led away (hot containment) so the two will never mix. Other options employed in hot containment can be the use of blanking panels, hard panel boards and PVC curtains in place of or augmenting duct work.

Advantages of Cold Aisle Containment:

  • Easier to implement as does not require additional design to contain exhaust air and return it to AC units
  • Only requires doors at the ends and a partition or roof at the top
  • Generally less expensive
  • Better results when used to retrofit an older data center
  • Enables greater surface area for “cold sinks” in the event of a power and/or generator failure

Disadvantages of Cold Aisle Containment:

  • The entire data center essentially becomes a hot aisle, making the space extremely hot, which could result in higher extreme exhaust temperatures
  • Increases the chances of mixing with return air which lowers the delta temperature
  • Cold air could leak from the raised floor tiles and openings under the equipment reducing the overall efficiency of the entire system
  • Fire detection for the overall data center space could be conflicted

Advantages of Hot Aisle Containment:

  • The operations area of the facility room is a cold environment
  • Any leakage from the conditioned air goes into the cold space
  • Statistically more effective at cooling
  • Performs well in the majority control room environments
  • Standard fire detection systems will not be impacted

Disadvantages of Hot Aisle Containment:

  • Almost always a bit more expensive
  • Space requires a contained duct work path to get air back to the AC units
  • Higher temperatures in the hot aisle can create uncomfortable temperatures for technicians

Peak performance is the main focus of another set of environmental controls. Air flow management, for example, is used to provide the efficient cooling of the center’s computers through the re-circulation of hot air exhausted from the machines. Temperatures recommended for data centers and similar facilities range from 68–75 °F (20–24 °C), although some studies have suggested that any temperature below 70 °F (21 °C) may waste energy. Overheating of the machines in the data center can result in the loss of performance or even complete failure of the devices. Over-cooling, alternatively, can lessen performance when used in areas of high humidity because it can lead to moisture and consequentially salt deposits to build up in the circuitry.

Another approach is the use of ventilated flooring tiles to build a containment system that controls the air flow directly to the cabinets. Average ambient temperature, ventilation leakage and server tolerance all go into the deciding the level of containment which is necessary for each specific data center.

In the end though, hiring a company who specializes in aisle containment is your best bet to finding a solution that best suits the needs of your industry.


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