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We can use the concept of exergy to analyze a human body as a heat emitter: while generating heat continuously, the body remains at roughly the same temperature through physiological responses such as shivering, sweating, breathing thus raising/decreasing the core and/or skin temperature to maintain effective heat dissipation. Existing literature provides an estimated exergy consumption rate of the human body ranging from 2 to 5 W / m 2 , while nearly unanimously agreeing on a local exergy consumption minima points to potential individual thermal comfort. To clarify the underlying assumptions used in the existing human body exergy models, we analytically and numerically reviewed the terms used for assessing metabolism, radiation, evaporation, and convection exergy changes of the human body in this paper. We observed overestimations of exergy from metabolism, underestimations of exergy change through radiation, and some caveats in the signage of convective exergy losses in the results we obtained. We were also able to propose an improved expression to estimate human body radiation exergy exchanges as well as selecting reference temperatures that are more process-specific. Future studies that provide experimental verification of these models were also deemed necessary. • Term-by-term comparison of existing human body exergy model expressions; • Showed T op/E cons minima combination for male/female occupants across age span; • Compared linear radiant heat transfer coefficient against actual radiation heat transfer; • Showed how reference temperature affects the sign of evaporation exergy loss. [ABSTRACT FROM AUTHOR]

Determining variations in air temperature and mean radiant temperature (MRT), two primary environmental parameters directly linked to thermal comfort, can be challenging. The ease and effectiveness of both measurement and simulation are quite different for determining air temperature and MRT. We review these challenges and present an experiment demonstrating how these differences in complexity and resolution can lead to challenges coupling these variables, whose effect on thermal comfort is interdependent. Bearing these challenges in mind, we measured and simulated the air temperatures and MRTs inside a radiantly heated high bay laboratory space. We found the spatial variation of the MRTs to vary by 5 ° C at the elevation of 1.3 m, which is much larger than the variations observed in air temperature. The variations in measured air temperature were up to 2 ° C. This calls for improvement to current tools and methodologies for measuring and simulating the radiant environment, particularly at locations closer to the exterior envelope where hot and cold surfaces affect both air temperature and MRT. It is important to improve the evaluation techniques for MRT, as we observe its spatial variation to be much greater than that of air temperature, while its measurement is limited and usually ignored in practice. • Simulated and modeled air and mean radiant temperatures distributions. • Used angle-factor-based MRT characterization when modeling 3D MRT. • Demonstrated rarely-captured spatial MRT variation in an indoor environment. • Discussed existing limitations in using Ta to evaluate indoor thermal environment. • Showed importance of integral indoor environment sensing and monitoring. [ABSTRACT FROM AUTHOR]