Sizing natural ventilation systems for cooling: The potential of NV systems to deliver thermal comfort while reducing energy demands of multi-storey residential buildings in India.

This paper aims to identify the potential of natural ventilation for cooling a representative twobedroom residential apartment layout in India. India faces an unprecedented demand for residences and must reduce energy consumption associated with air-conditioning. Three significant climates and cities in India are investigated in this paper. The potential to extend the hours of the year for which thermal comfort is achievable using natural ventilation strategies is tested. This potential is identified by employing analytical methods to design and size ventilation capacity. Five natural ventilation design strategies are used over several scenarios varying window free area and ceiling fan speed. Indoor temperature setpoints are based on the India Model for Adaptive Comfort. Results are given as percentage of hours of the year for which natural ventilation is capable to remove calculated heat gains. Percentages of hours are divided into day-time and night-time. Findings show that the combination of large windows or balcony doors with additional ventilation openings and ceiling fan increases the total percentages of hours of the year for which natural ventilation is effective impacting on substantial energy consumption reduction with air-conditioning. Conversely, this potential varies with climate, and hence location.