Energy Retrofits for Improving Energy Efficiency in Buildings: A Review of Hvac and Lighting Systems

Abstract

It has been observed that inefficient buildings consume three to five times more energy than efficient buildings. Subsequently, improving the Energy Efficiency (EE) of existing buildings, which account for a significant portion of the energy consumption of the building sector, has become a top priority. Also, Heating, Ventilation, and Air Conditioning (HVAC) and lighting systems typically account for three-quarters of a building's energy consumption. Hence, focus on the energy efficiency improvements associated with these subsystems is entailed to optimise the energy use of buildings in comparison to other energy consumers. Energy Retrofit (ER) is defined as the main approach in improving the energy efficiency of buildings to achieve energy reduction goals. Nevertheless, there is a general lack of awareness regarding ER. Thus, the purpose of this article is to bridge this research gap by critically reviewing the applicable literature on ER. The paper first analysed the role of retrofits in buildings concerning optimising energy performance. The paper also discusses the implementation process of ER, which includes five steps viz. pre-retrofit survey, energy auditing, and performance assessment, identification of suitable and feasible retrofit options, site implementation and commissioning, and validation and verification. Further, different types of ER applicable to HVAC and lighting systems are discussed. In their endeavor to enhance the EE of existing buildings, practitioners could apply the findings of this study, as a basis to understand the available ER types and as a measure to gauge the efficiency of existing buildings, which will facilitate effective decision-making.

The impact of the new EPBD “Green Houses” in the Italian building context: Technical-economic analysis on improving the energy class of existing buildings

“…Building external insulation has, indeed, a high potential of reducing energy needs and this has been proven in several circumstances [27,28]. Also the renovation of the Heating Ventilation and Air Conditioning (HVAC) system is among the most effective ERMs [29] and may lead to major improvements in energy efficiency of building operation [30]; moreover, in heritage buildings this intervention may have, in some cases, the benefit of a lower invasiveness compared to external insulation. In this context, renewable energy has a key role in the attainment of low carbon energy systems [31], and the integration of renewable energy technologies in retrofit interventions upon the existing building stock is crucial for sustainable development [32].…”

Technoeconomic Comparison of Retrofitting Options towards Green Buildings

“…Mukhtar et al analyzed and summarized the energy and environmental benefits of retrofitting the existing electric heaters for hot water and ordinary air conditioners for space heating with energy-efficient alternatives [19]. Amjath et al summarized the implementation process of energy retrofit and different types of energy retrofit related to HVAC and lighting systems with the purpose of providing a reference for project decision makers [20]. Wang et al presented a multi-objective optimization model for retrofitting planning of building indoor facilities to help decision makers to make the best use of the available budget [21].…”