Recent improvements to heating, ventilation, and cooling technologies for buildings based on renewable energy to achieve zero-energy buildings: A systematic review

Due to global climate change and energy market turmoil, the world is seriously pushing to switch to renewable and diversifying energy sources. The building sector consumes an amount of energy, accounting for approximately 40 % of global energy. Therefore, the concept of zero-energy buildings has become more realistic than before. This study reveals the latest developments in zero-energy buildings through a comprehensive literature review of the past ten years. Emphasis has been placed on buildings' heating, ventilation, and cooling systems, as they constitute the most important part of the energy demand. Also, the role of negative energy resulting from an improved building envelope through the design of a building compatible with the surrounding environment, thermal insulation materials, phase change materials, vegetation cover, etc. A review was also made of the most significant renewable energy technologies, which include solar energy installations, wind turbines, and geothermal heat exchangers. The study showed that three main axes must be achieved to reach an energy-free building: Reducing energy waste through the energy-conserving building envelope and improving HVAC systems. Raising the efficiency of the performance of renewable energy facilities by using hybrid systems with the ability and flexibility to respond to changing energy demand. These three axes are an integrated approach to achieving ZEBs; none can be neglected. This study provides important references for researchers, institutions, and decision-makers to unify efforts to achieve ZEBs. It also aims to attract attention and focus research by raising questions and identifying gaps that future research efforts can address.