The function of the electronic devices can be highly affected by the ambient temperature. A rough rule of thumb is that by increasing 10˚C in the data centre, the failure rate is doubled [1]. The recommended temperature range by ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning Engineers, for a data centre is 18-27˚. The optimal range of relative humidity is 40-60% to avoid the static electricity and preventing condensation on colder plastic and metal surfaces.

Data centres are intensive energy users, approximately 1.5% of global electricity consumption. About 45% of this energy is spent on the infostructure i.e., cooling, fans, and compressors [1]. Anders Andrae [2] predicted that data-centre electricity use is likely to increase about 15-fold by 2030, to 8% of projected global demand.

A computer room air conditioning (CRAC) unit is a device that monitors and maintains the temperature, air distribution and humidity in a data centre. The air-based cooling is the mostly used cooling units due to the ease of implementation and the reduced risk of liquid leakage among other type of CRAC’s. The cooled air flows through raised floor. Here, we use OpenFOAM to evaluate the airflow rate and thermal loads on a data centre. We used bouyantSimpleFoam as CFD solver with the assumption of Boussinesq state equation to simulate the air flow and predict the temperature distribution in a data centre consisting of three row of racks which generates a total heat load of 105 kW.

Figure 1. Data centre sketch

The other data centre description is as follows:

Room dimension: 11 × 7 × 3 m3

Number of CRAC units: 4

Number of rack rows: 3

Heat source for each rack row: 35 kW

Total flow rate: 6 m3/s

Supply air temperature: 22 °C

Figure 2. Streamline in the data centre and the temperature distribution.
Figure 3 Temperature distribution in different sections

Figure 4. Streamline in the data centre and the velocity distribution.