energy recovery

Energy recovery systems capture **waste heat, pressure differentials, and other energy byproducts** from semiconductor fab operations for reuse, reducing total facility energy consumption by **10-30%**. **Recovery Methods** **Heat exchangers** capture waste heat from process cooling water, exhaust air, and chiller condensers to preheat incoming fresh air, DI water, or chemical baths. **Heat pumps** upgrade low-grade waste heat to useful temperatures for building heating or process applications. **Exhaust heat recovery** uses heat wheels or run-around coils to transfer energy from fab exhaust air (maintained at 20-22°C, 40-45% RH) to incoming makeup air. **Chiller waste heat**: Chillers reject 1.2-1.5× the cooling load as heat, which can supply building heating and DI water preheating. **Fab Energy Breakdown** • **HVAC/Cleanroom**: 40-50% of total fab energy (largest consumer) • **Process Tools**: 30-40% (plasma, heating, pumping) • **DI Water/Chemical Systems**: 5-10% • **Lighting/IT/Other**: 5-10% **Economic Impact** A modern 300mm fab consumes **50-100 MW** of electrical power. At $0.08/kWh, annual energy cost is **$35-70 million**. A 20% energy recovery saves **$7-14 million per year**. Heat recovery systems typically pay back in **2-4 years**.