Advanced air distribution: improving health and comfort while reducing energy use

Abstract

Indoor environment affects the health, comfort, and performance of building occupants. The energy used for heating, cooling, ventilating, and air conditioning of buildings is substantial. Ventilation based on total volume air distribution in spaces is not always an efficient way to provide high-quality indoor environments at the same time as low-energy consumption. Advanced air distribution, designed to supply clean air where, when, and as much as needed, makes it possible to efficiently achieve thermal comfort, control exposure to contaminants, provide high-quality air for breathing and minimizing the risk of airborne cross-infection while reducing energy use. This study justifies the need for improving the present air distribution design in occupied spaces, and in general the need for a paradigm shift from the design of collective environments to the design of individually controlled environments. The focus is on advanced air distribution in spaces, its guiding principles and its advantages and disadvantages. Examples of advanced air distribution solutions in spaces for different use, such as offices, hospital rooms, vehicle compartments, are presented. The potential of advanced air distribution, and individually controlled macro-environment in general, for achieving shared values, that is, improved health, comfort, and performance, energy saving, reduction of healthcare costs and improved well-being is demonstrated. Performance criteria are defined and further research in the field is outlined.

Entrainment and its implications on microclimate ventilation systems: Scaling the velocity and temperature field of a round free jet

“…Traditional air distribution systems (eg, mixing ventilation) have sought higher entrainment to increase the system dilution or mixing capacity . Today, there is a call for a paradigm shift in indoor air distribution from total volume systems to microclimate systems, whose optimal operation (delivery of clean supply air) depends on low entrainment, for example, personalized ventilation systems . Earlier, we raised the importance of distinguishing between total volume ventilation systems (operate on dilution of room air) in which high entrainment is sort after and microclimate ventilation systems that require low entrainment .…”

An indoor environment evaluation by gender and age using an advanced personalized ventilation system

“…The perceived air quality is influenced by the ATD type, air flow rate and the distance between ATD and breathing zone [4]. The PV systems can be used alone or combined with TVAD systems and local heating or cooling solutions [5].…”

Airborne spread of expiratory droplet nuclei between the occupants of indoor environments: A review

“…41,[49][50][51][52][53][54][55] Room air pattern and ventilation airflow rate are 2 key factors shaping indoor air distribution. Compared to the total volume air distribution, advanced air distribution methods, such as personalized ventilation (PV) 56 and personalized exhaust (PE), 57 have shown a better performance in reducing the risk of cross-infection by airborne transmission. 58 Recent studies 47,59,60 of the human micro-environment reveal that the rising plume around a human body could, on the one hand, entrain pollutants in the vicinity and elevate the exposure concentration, 61,62 and on the other hand, function as an air curtain that protects the occupant from the incursion of expiratory flows from others.…”