Experimental and Numerical Investigation of the Effects of Passive Radiative Cooling-Air Layer Composite Envelope Structure on Building Energy Consumption for Data Center Rooms

The energy consumption of data centers has become increasingly prominent. To address the conflict between the characteristic of inhibiting heat dissipation for traditional insulated building envelopes and the cooling demands of data center rooms all year, this study proposes a novel composite envelope structure for data center rooms that integrates passive radiative cooling with air-layer insulation (PRC-AL). The results demonstrate that under internal heat source power densities of 300–1000 W/m2 without additional cooling measures, the PRC-AL composite envelope structure reduces indoor air temperatures by 16.16–30.81% compared to the traditional insulation structure (TIS). Meanwhile, the application of the PRC-AL composite envelope structure leads to significant reductions in annual cumulative cooling load per unit area: 1617.69 kWh/m2 in Harbin, 1359.49 kWh/m2 in Tianjin, 1135.25 kWh/m2 in Shanghai, 994.97 kWh/m2 in Guiyang, and 918.70 kWh/m2 in Guangzhou. These findings indicate that the proposed PRC-AL composite envelope structure not only effectively lowers indoor air temperatures but also reduces cooling loads in data center rooms, providing an efficient pathway for energy conservation in data centers. This research offers a theoretical foundation for optimizing the design of building envelopes in data centers and contributes to sustainable development in the digital infrastructure sector.