Retrofitted Existing Residential Building Design in Energy and Economic Aspect According to Thailand Building Energy Code

Abstract

Electrical energy usage in buildings is a challenging issue because many old buildings were not originally built to achieve energy efficiency. Thus, retrofitting old buildings to net-zero buildings can benefit both the owner and electric utilities. In this study, the BEC (building energy code) software was used to evaluate energy aspects of retrofitted buildings in compliance with Thailand’s building energy code to achieve a net-zero energy building. In addition, economic aspects were also studied to verify the feasibility for a project’s owner to invest in a retrofitted existing building. An existing residential building in Thailand was used as a case study. The results in terms of energy after retrofitting existing buildings into net-zero energy buildings show that the total energy consumption can be reduced by 49.36%. From an economic perspective, the investment cost for a retrofitted building can be compensated by energy saving in terms of discounted payback period (DPP) for approximately 4.36 years and has an IRR (internal rate of return) value of 19.23%. This result evidences the potential in both energy and economy for a project’s owner to invest in a retrofitted existing building in compliance with the building code, with potential for implementation with benefits on both electrical utilities and the project’s owner.

Toward ZEB: A Mathematical Programing-, Simulation-, and AHP-Based Comprehensive Framework for Building Retrofitting

“…Lumen(per lamp type j) * X ij /space area ≥ Required LUX level (10) where j represents the different lamp types available [33].…”

“…Retrofitting measures may include adding wall insulation, changing electrical equipment to more energy-efficient ones, downsizing the HVAC system according to the cooling load, or investing in renewable energy technologies [9]. For instance, to help achieve net ZEBs for existing buildings, the authors in [10] used the Building Energy Code (BEC) software and Thailand energy code for a building's retrofitting evaluation along with economic analysis. The authors reported an energy consumption reduction of almost 50%, a 4.36-year discounted payback period (DPP), and a 19% internal rate of return (IRR).…”

Analysis of Hotel Façade Thermal Performance with a Special Reference to the City Hotels in George Town, Penang

“…OTTV is a performance-based evaluation method [5], and its output relies on the thermal building environment [1]. In the performance-based evaluation method, the emphasis is given to quantifying the total building performance.…”

Energy system transformation for attainability of net zero emissions in Thailand

“…Reduction in energy consumption by 5 % to 10 % could be achieved by feedback and more informative billing [40]. Ananwattanaporn et al evaluated the reduction in energy consumption by retrofitting existing buildings in compliance with Thailand's building energy code to achieve a net zero energy building and estimated that energy reduction up to 49.4% could be achieved [41]. Gulati studied the cost effectiveness of HVAC through step-by-step optimization of building orientation, window-to-wall ratio, roof, wall, glass, and shading devices [42].…”