Energy metrics of a hybrid earth air heat exchanger system for summer cooling requirements

• A hybrid EAHE experimental setup is tested to attain proficient cooling performance of the conventional AC system utilizing geothermal energy.
• Objective of experimental study is to increase the usage of energy efficient renewable resources.
• Hybrid EAHE system makes available significant amount of energy conservation.

Rapid increase in cost of power, its shortage and impact on environment, compels us to use innovative energy efficient technologies for space heating/cooling. Reduction in power consumption in vapour compression based conventional air-conditioner with air-cooled condenser is a difficult task especially in hot and humid weather conditions (Central region of India), where the summer temperature sometimes exceeds 46 °C. Power consumption of conventional air-conditioner can be reduced substantially by hybridizing it with earth air heat exchanger system. In the present research, an effort has been made to reduce the power consumption of 1.5 TR window air-conditioner by coupling with earth air heat exchanger system in three different arrangements. When entire cold air from earth air heat exchanger system is supplied to cool the air-conditioner’s condenser coil, the power consumption is found to be reduced significantly in hybrid system as compared to conventional 1.5 TR window air-conditioner. The economic analysis techniques i.e. simple payback period, discounted payback period, net present value and internal rate of return validate that proposed hybrid arrangements are economically viable.