To Examine the Energy Conservation Potential of Passive & Hybrid Downdraught Evaporative Cooling: A Study for Commercial Building Sector in Hot and Dry Climate of Ahmedabad

Abstract

Energy consumption in the building sector is very high and it is expected to increase further due to increase in standards of living and change in typology of the building. Other major factor which has a significant effect on energy consumption is climate, especially in hot and dry climate. There is vast temperature fluctuation in such type of climate promoting greater use of air conditioning system, thus increasing energy consumption. The Study examines the energy conservation potential of the Passive Downdraft Evaporative Cooling (PDEC) technique for the commercial building sector in hot and dry region of Ahmedabad. The Study examines four different scenarios, 1) Conventional Case, 2) Envelope Design case 3) Energy Conservation Building Code (ECBC) Envelope Design case and 4) ECBC Envelope Design case with Evaporative Cooler (EC). Performance of all scenarios is measured through simulation software ‘eQuest’. Simulation results are compared with actual building observations and comparative analysis is done in terms of Cooling load, Energy consumption, CO2 emissions and other co-benefits. The Research finding proves that Passive Downdraught Evaporative cooling technique offer real opportunity for improving indoor thermal comfort conditions in a building whilst reducing cooling load of air-conditioning systems, thereby reducing energy consumption and provides better indoor environment by providing 100% fresh, cool air into a space. The analysis confirms the advantage of such passive cooling strategy in hot dry climate of Ahmedabad. Further research also identifies the significance of the integrated architectural approach.Result of the each scenario with better envelope design and efficient cooling technique has shown significant energy conservation.The findings clearly suggest that while energy efficiency can be achieved through building regulations/codes and appropriate choice of materials/construction technology, but the potential for energy efficiency is much higher when such measures are integrated into the design philosophy and approach. The results can be used to estimate the energy conservation potential of such technique for wider application and also in developing recommendations to encourage the use of such passive cooling techniques. As commercial building floor area in Ahmadabad is projected to be double by 2035[1], there is a large potential to conserve the energy. Developing guidelines and action plan to promote such techniques will certainly help to reduce energy consumption, hence reducing GHG emissions.