ANNOUNCEMENTS
This study aims to figure out ways to advance the energy-efficient and thermally comfortable affordable houses for all climatic zones provided under the Pradhan Mantri Awas Yojana (PMAY) scheme implemented by the Ministry of Housing and Urban Affairs (MoHUA) in 2015 (MoHUA, 2015). The method required to analyze approaches required a review of the mandatory norms given under the scheme, identify the cost-effective strategies to improve energy efficiency and thermal comfort. These strategies include implementation of passive design strategies such as the orientation of the building, shading, Window glazing systems, etc and also some of the low-energy cooling technologies.
The key objective in this thesis is to reduce the overall building energy consumption, and maximize thermal comfort. The case study chosen has been for Delhi for the study.
Delhi Development Authority has planned to construct affordable houses under the DDA, EWS scheme in 2019. This scheme is under the flagship of PMAY-U scheme. The number of houses sanctioned are more for Lower Income Group and Economically Weaker Sections.
The methodology used in this thesis is to analyze the overall building energy consumption and no of discomfort hours associated with it, and also look into the effect of costs associated. The Energy Efficiency and thermal comfort are set to be optimized in order to obtain the best results.
The first step was to collect necessary data needed to formulate the Base model for simulation on EnegryPlus. The base model for simulation is a 1 BHK house belonging to a Lower Income Group (LIG) (Delhi Development Authority, 2019). The business-as-usual practices were collated for the study and analysis. These houses predominantly used Monolithic Concrete Construction which has a high U-value (BMPTC, 2017), and lighting used were LED (Prayas Energy Group, 2018).
The building is then subjected to parametric analysis and optimization where the objective functions are between Building Energy Consumption (U) and Number of Discomfort hours. The functions are to be minimized and are subjected to various design parameters. The most optimal solutions are obtained and the energy savings are computed. There were 19 optimal solutions after the optimization, out of which solutions giving minimum 20% or more were shortlisted for analysis. The analysis was carried to study the thermal comfort in the building for two cases: Building with the dummy load and Naturally Ventilated Building. Cost was also considered based on the payback period. The energy efficiency package 5 was considered to give the best results in terms of all three and also for both the cases. It consists of a low U-value of 0.74 W/m2-K, Window to wall ratio of 30% with Double glazing with a high SHGC with air gap, cool roof such as PVC white of higher solar reflectance of 0.83. The buildings are oriented towards South Direction. This recommendation has significantly increased the comfortable hours by 1200 hours, and shows great reduction to 33°C which is considered the most comfortable temperature, and incremental cost is not much compared to the base model. The increase is about 0.7% which can be considered feasible.
The same recommendations were provided for Rajkot affordable housing (Indo-Swiss Building Energy Efficiency , 2020) which belongs to composite climate (NBC, 2016). The reduction in the Residential Envelope Transmittance Value (RETV) also significantly reduced from 20.74 W/m2 to 9.04 W/m2.
