Ventilation and energy efficiency in Air Systems for future buildings: a four dimensions approach.

Recent pandemic events are combined with a growing awareness of environmental issues, a general focus on sustainability and responsibility for future generations. All these issues converge towards a general need to improve the performance of buildings and at the same time reduce energy costs. This paper presents four different areas of improvement applicable to air systems on which it is felt that the time has come to focus conceptual and technological efforts. The four dimensions of the proposed improvement are as follows: The reduction of air leakage, the optimization of air diffusion control in VaV applications, the implementation of selective systems for the removal of specific contaminants, the system-wide contextualization of heat recovery from exhaust air. The four directions indicated are considered to offer the greatest potential for optimization in the context of air systems, and this is all the more true if these paths are taken simultaneously. They are aimed at minimizing energy effort (i.e. treated air flow rates) while maximizing performance in terms of maintaining indoor air quality. This can be done by repositioning the boundaries that until now have not allowed the full potential offered by a wise application of variable airflow systems. The approach presented is mainly a performance-based approach re-evaluated in the light of improvements in manufacturing and component characterization technologies, the possibility of considering air systems as a potentially synergistic part of more complex systems, and new sensitivities developed following the advent of pandemic events. The potential improvements in percentage terms from such an action promise to be greater than any single component implementation, but they require a change of attitude on the part of designers and a readiness on the part of manufacturers to work towards the development of standardized procedures applicable on a large scale.