Assessment of ThermODrain system on Thermal Comfort – Study of a Multi-storied Office Building in Nashik, India

A ThermO-Drain (TOD) is a system that uses water cooled by night sky to drain the radiant heat within a building. In office buildings, ‘all air-cooled’ systems are most prevalent. The study aimed to assess the thermal comfort of occupants in a ground and two storied naturally ventilated office building in the composite climate of Nashik in India where TOD system was installed. Assessment was conducted by taking hourly readings over a 25-hour period in peak summer of May 2017. Primary data collected included Dry Bulb Temperature (DBT) and Relative Humidity (RH) indoors, surface temperature of top and bottom of roof slab and Globe temperature within the office. Secondary data for the same period was obtained from the Indian Meteorological Department (IMD). Monthly electricity bills were used to measure the Energy Performance Index (EPI). The Tropical Summer Index (TSI), an index suggested in the National Building Code (NBC) 2016 of India, was calculated. Results show that the indoor operative temperature in the peak of summer with outdoor temperature of 36.30C was found to be close to the neutral temperature of 27.50C. The EPI of 26.5 kwh/m2/year falls within the BEE 5-star rating of below 40 kwh/m2/year.