Owing to the development of radiant heating/cooling systems and personal ventilation, a new trend has arisen where heat is dissipated to several independent areas, providing custom heat loads; this allows the possibility of creating a zero heating/cooling load environment, i.e., it allows us to deal with the heat load from each heat source before the heat diffuses into the space. This solution enables us to utilize lower level heat sources such as chilled water at high temperatures and heat at a low temperature. It also ensures more uniform temperature distribution and a more comfortable Personal Microenvironment with improved energy efficiency.

Significant HVAC energy savings can be achieved by widening the thermostat setpoint range and providing local thermal management to restore occupant comfort. This is achieved through the use of an efficient 50-60 W personal environmental control system designed for the thermal management of the personal microenvironment. Specifically, we analyze the performance of a micro environmental control system that increases occupant’s sensible heat loss in a room maintained at 79F in the summer, and reduces occupant’s heat loss in a room maintained at 66F in the winter. CFD is employed to assess the system performance under different operating conditions.

The characteristics of the personal micro-environment, consisting of the thermal plume, clothing, gap between skin and clothing, and respiration, will be defined. The importance of free convection around the body and its interaction with external flows, clothing and the resulting heat- and mass transfer for thermal comfort and inhaled air quality will be outlined. The benefit arising from measurement and control of the micro-environment, in terms of sensing body physiological signals, improving people’s thermal comfort and inhaled air quality, reduction of exposure to airborne infectious agents and energy saving will be demonstrated by several methods that are applicable in practice.

In this seminar, the speaker gives a brief introduction of the human thermal plume dominated zone (HTPDZ) around the human body created by the human thermal plume. He then addresses the negative and positive role of the HTPDZ on the contaminant cross transmission between person to person. He will also use examples to explain how the HTPDZ affects the contaminant cross transmission under different conditions, contaminant cross transmission in vertical unidirectional ventilated protective isolation environment and aircraft cabin environment.