Design of an Earth-Air Heat Exchanger System for Space Cooling in Climatic Conditions of Nagpur, India

Abstract

Earth Air Heat Exchanger (EAHE) system is a Passive Cooling technique which uses earth’s potential to maintain a constant temperature throughout the year at certain depths as a source or sink to cool air during summer and vice versa in winter for space air-conditioning application. EAHE systems are best suited in hot and dry climatic conditions because EAHE systems in humid areas face challenges of condensation of water and contamination by microorganisms. Commercial Heating, Ventilation, and Air Conditioning (HVAC) systems are now established everywhere because there are standard methods for their calculations and manpower for installation. EAHE systems, being in their early stages lack such standards, installations guidelines and hence have less commercialization. One such effort has been made in this paper to design an EAHE system for a classroom in a hot and dry climate of Nagpur City, India. Heat exchanger calculations were made based on the NTU method, air flow rates were referred from ASHRAE ventilation standard and a piping layout is created so as to use the designed system for commercial purposes.