Smart Green Buildings of Tomorrow

Abstract

Fast population growth and rapid development of our communities have exerted a huge impact on our natural environment. The design, fabrication, construction and operation of buildings in which we live and work are responsible for significant consumption of our natural resources. Taking the United States as an example, buildings account for 39% of total energy use, 68% of total electricity consumption, 30% of landfill waste, 38% of carbon dioxide emissions and 12% of total water consumption [1] and China is catching up. In order to alleviate the problem, smart green buildings development could well be considered as one of the viable choices. As its name suggests, smart green buildings combine ‘‘smart’’ and ‘‘green’’ concepts. Green buildings are about resources efficiency, lifecycle effects and building performance while keeping the lowest impact to the environment. Smart buildings, in which the core component is an integrated building technology system, are about construction and operational efficiencies, enhanced management and occupant functions. Therefore, the environment, economy and society can benefit from smart green buildings by enhancing and protecting biodiversity and ecosystems, improving air and water quality, reducing waste streams, conserving and restoring natural resources. Besides, smart green buildings can reduce operating costs, improve occupant productivity, enhance asset value and profits and optimize life-cycle economic performance. They can also enhance occupant health and comfort, improve indoor air quality, minimize strain on local utility infrastructure and improve overall quality of life. From another viewpoint, the minimum function of traditional buildings is to provide a shelter. Strength, durability, cost on selecting building materials, planning and construction are focused by civil engineering while aesthetics, comfort and attention to fulfilling psychological needs of the occupant are stressed by architecture. However, smart green buildings seek to conserve and utilize natural resources, emphasize eco-friendly construction and minimize carbon footprint on a global scale. The trend of the development is that smart green buildings should manage to cater more for the needs of humans, with increasing magnitude of personalization. People will be in control of the environment and be able to tune it to their needs. A lot of research activities are being carried out to make our buildings smarter and greener. Absorption, adsorption and various advanced thermodynamic cycles could be considered as renewed interest in thermally activated cooling and heating systems. Micro-channel systems could help improve heat and mass transfer, leading to reduction of fluid inventories, material utilization and environmental impact. Integrating micro-channel systems into smart green buildings could make those buildings more energy efficient. Apart from that, integrating novel heat transfer fluids (e.g. nanofluid) [2] as well as improved heat and mass transfer devices into heating and cooling systems can also further reduce the energy consumption and ecological footprint of some building systems. A trigeneration process is another option to increase the efficiency in thermal and electric generation. Recently, the tri-generation system has been used for power generation and also for air-conditioning systems. Comparing with the co-generation system, tri-generation refers to district energy which can achieve a higher efficiency with a smaller environmental impact. With a