Futureproofing with Passive Buildings: Is it Cost Effective and is it Thermally Adequate?

Amanda Thounaojam, Prasad Vaidya, Sanjay Prakash  | 2023


The paper aims to highlight the importance of employing a robust Life Cycle Cost (LCC) method that incorporates future weather files and a calibrated model. The study evaluates a 50-year LCC for wall insulation in an experimental building in Bangalore. It compares the LCC calculated using the future weather data with results obtained using the Typical Meteorological Year (TMY) file, providing a more accurate assessment of long-term cost-effectiveness.

The results show that insulated walls have a lower LCC when fully air-conditioned, while mixed-mode settings show higher LCC. A detailed thermal comfort analysis indicates that insulated walls offer adequate thermal comfort (11-13% discomfort hours) under full adaptation to thermal conditions. Without full adaptation, when the adaptive comfort equation of the National Building Code (NBC) will not work, discomfort could rise to 31%. However, with ceiling fans (6-7oC cooling power index), it would suffice to provide comfort in the experimental building. The study underscores that well-designed buildings in Bangalore with insulation, passive strategies, and natural ventilation can ensure prolonged comfort without mandatory air-conditioning.