An economizer is a device that is used to reduce energy consumption in a data center. Be it a water- side economizer or an air- side economizer, with the astronomical electricity bills the data centers have to deal with, one can see why these devices are popular.
Types Of Economizer
An air- side economizer takes in the air from the atmosphere whenever the external conditions are optimal. The cool air from the outside is directly introduced into the data center without it having to go through the refrigeration cycle, thus saving energy. This is also known as free cooling. Water in a data center is used in the chiller systems. The heat exchanger uses air to cool the water in the chiller system. The water- side economizer pre-cools the water so that the cooler condenser does not have to work too hard to achieve the desired cooling levels again leading to lower energy consumption.
It is understandable that no compromise can be made on the cooling needs of a data center. But the fact still remain that they do operate at a much lower temperature than necessary. Cooling drawing almost 45 percent of the data center power is now raising concerns among businessmen and government regulatory bodies alike.
ASHRAE recently updated its standard on data center efficiency and it has mandated the use of economizers whenever and wherever possible especially in regions where the climate is cool enough to draw air directly, completely bypassing the compressor- based cooling. Institute of Energy has asked the manufacturers to come up with chiller- less designs. This not only brings down the operating costs, it also brings down the bomb of an investment that you would have to make on the chiller itself.
Is an Economizer Suitable for My Data Center?
One has to keep in mind a few drawbacks of the economizer; humidity extremes can force the economizer to turn off and fall back on compressor based cooling. The temperature of the air entering the data center may also be only a few degrees higher than the external temperature. Rigid steps must be taken to restrict the level of contamination while using an economizer.
But the question still remains on how effective or justified is ASHRAE by mandating the use of economizers in the data centers. One cannot exactly depend on the economizer one hundred percent; the system is effective only when the environmental conditions outside the data center are optimal. During the summer or in hot climates, the system is not very helpful to begin with.
Air- side economizers are more or less like automated windows that can be opened or closed at will. The dust and the pollutants that the device will bring into the data center cannot be overlooked. Accumulation of dust in the data center brings down the system efficiency of the whole data center. Even though the dust and the pollutants can be contained by installing filters, the filters should be checked and emptied/ replaced regularly.
Although the installation of an economizer is no drawback, the energy it ends up saving in an extreme climate sure is debatable. There are more than one ways to bring down the cooling costs, which are more effective than an economizer. Engineers are even coming up with effective designs for chiller- less water economizer. Explore your options before you zero in on the system of energy efficient cooling that suits your data center the best.
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