Data center computer room air-conditioning equipment operates for prolonged periods

and its performance must be tested and evaluated annually to ensure safe and efficient operation. This study conducts field measurements on the server layout

blind plate structure

and working condition adaptability in the rack. The thermal environment of a data center using the closed cold aisle underfloor air distribution system is studied

and the thermal environment safety and energy efficiency throughout the year are evaluated through thermal performance indicators and energy efficiency indicators. The results show that it is recommended to install a rack with a power of more than 2 kW in the middle area of the cold aisle. Installing a blind plate in the gap between the racks can promote the circulation of cold air inside the server

reduce the backflow interference of hot air

and reduce the maximum outlet temperature by 3.32 °C. The average supply air speed was reduced by approximately 24%. Under summer operating conditions

the PUE

WUE

and CUE of the data center were approximately 1.2

3.5

and 0.84

respectively

and the WUE exhibited strong seasonality. Under winter operating conditions

free cooling can effectively reduce the energy consumption of data centers. In addition

the overheating problem of the racks at the end of the cold aisle of the data center is significant. The cabinet cooling index of the 16 racks was less than 90%

and the heat loss was high.