Free cooling


Free cooling

Free cooling can be described as air conditioning of a data center with outdoor air. If you take into account that more than half of the year the outside temperature in Germany is lower than the required temperature in a data center and at night, there are almost always temperatures below 20 degrees, it becomes clear there can be substantial savings in cost of energy when using the “cost-“free cooling source.

But it should be also clear that air conditioning can never be conducted only by outdoor air, as sometimes it is simply not cold enough in our latitudes. A combination with power driven cooling which can be used if required, is therefore imperative.

In principle, you can distinguish two types of free cooling: The direct free cooling in which outdoor air is streamed directly to the data center and indirect free cooling which uses outdoor air only to withdraw warmth from a cooling medium like water or cryogen. However, depending on size and composition of the data center, there are a lot of individual solutions or combinations, which all follows one of the two principles.

Direct free cooling

With the direct free cooling the cool outdoor air is streamed directly to the data center. This has the advantage that the cooling capacity of the outdoor air will be used optimally, helping in saving up to 85% of operating cost.
his offers greatest possible saving potential with energy costs for air conditioning. Furthermore this method requires controls, filters and feedback systems to preserve air quality, humidity and temperature within desired parameters.

Indirect free cooling

With indirect free cooling a cooling medium which cools the inside air is in turn cooled down by the cold outdoor air. Opposite to direct free cooling, this has the advantage that atmospheric humidity and pollution of the outdoor air does not represent danger for the data center. Clean inside air circulates in a closed system.

However it enables the use of free low temperature air, although the cooling capacity of the air will not be optimally used, due to double handing of cold from one medium to another. An indirect free cooling can only be used up to 10 degrees centigrade, whereas the direct free cooling can be used up to 22 degrees centigrade outside temperature, increasing the timeframe of use in Germany considerably.

In both cases there still are considerable cost advantages of the energy in comparison to a pure power-based cooling.

Both versions of the free cooling are ecological and economical sensible, it depends on the respective data center which option will be more advisable.

To judge the many combinations and solutions, we offer you specialized knowledge and our experience. Don’t hesitate to ask us, we’ll take care of IT.


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