Integrating the distribution of chilled water and supply air for energy-efficient cleanrooms in high-tech industries: A demand-responsive approach

Cleanrooms are vital to the energy-intensive semiconductor industry, where precise air-conditioning (AC) systems are essential yet consume substantial energy. A key inefficiency stems from chilled water and air supply systems operating independently, each with redundancy that can be reduced by coordination. This study proposed and quantified the energy-saving potential of integrating these systems using a demand response approach. Four schemes, i.e., single-pump constant flow (SC), single-pump variable flow (SV), two-stage direct pump (TD), and two-stage heat exchange (TH), were proposed and validated using Modelica-based simulations. Their energy performance was analyzed based on advanced configurations and climate conditions in Hefei, China. A novel coordinated variable frequency control method was developed to integrate chilled water and air supply systems under variable loads, enhancing demand response capacity. Results revealed that SV and TD schemes reduced the total energy consumption of the AC by 11.5 % and 0.8 %, saving 775,000 kWh and 55,000 kWh per season for a 5000 m² cleanroom. Additionally, by optimizing the fan-to-pump power ratio, coordinated fan-pump control achieved up to 73.6 % energy savings in circulation systems under partial loads. These findings underscore the critical importance of integrated control strategies in optimizing energy efficiency for cleanroom operations.