Optimization of Ambient Energy Component in Large Mixed Mode Central AC Plants

This paper presents the study of energy efficiency improvements of central air conditioners (AC) through the optimal integration of natural air ventilation functions. There is potential for energy saving through the shifting to mixed mode air conditioning invoking the ambient energy for cooling. An optimization study shows that up to an ambient temperature of 22˚C, passive cooling can be used and beyond that temperature active cooling is required. Simulation of energy consumption for air condition has been undertaken in 5 major cities of India, viz., Bengaluru, New Delhi, Mumbai, Kolkata and Chennai. The energy efficiency specified as per ECBC (energy conservation building code of India) is 80-90 kWh/m²/year for AC and can only be reduced through passive cooling components. Results indicate that it is possible to reduce the energy consumption by almost 50% through the use of natural air ventilation cooling.