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Numerous metrics and indices have been proposed for the assessment of thermal perception and comfort. Commonly used indices based on the estimate of the heat flow between the human and its environment includes the well-known Fanger's method, also known as the PMV-PPD thermal comfort model. Recently this thermodynamic approach has been expanded with the application of the second law of thermodynamics. In this paper, an exergy-based analysis of the relation between the human and its environment is presented. Heat and mass flow rate due to convection, radiation, evaporation and respiration are calculated and expressed in terms of exergy loss. This value is used in the modified Fanger's thermal comfort model, where the heat balance equation is replaced by the exergy loss. The paper builds upon prior studies on determination of internal and external exergy losses by revised and newly defined formulas taking into account clothing and indoor conditions. The results quantitatively show that thermal energy load in the original Fanger's PMV model could be substituted by exergy loss and it corresponds to a certain level of subjective assessed thermal comfort level. [ABSTRACT FROM AUTHOR]

Exergy-based (exergetic, exergoeconomic and exergoenvironmental) analyses, are used for designing, assessing and improving energy conversion systems. In an exergoeconomic analysis, thermodynamic inefficiencies – represented by exergy destruction – are used in combination with investment costs to calculate the “cost-optimal” layout of a plant. Analogously, in an exergoenvironmental analysis, the aim is to minimize the total environmental impact of a plant. Until today exergoeconomic and exergoenvironmental analyses have been used as separate and distinct tools and the improvement of a plant has been considered in terms of the reduction of either costs or environmental impact. To simultaneously decrease the investment costs and the component-related (manufacturing or construction-related) environmental impacts, their relationship with exergy destruction must be studied in parallel. This paper examines the relationship between exergoeconomic and exergoenvironmental data under various plant operating conditions. A combined-cycle power plant is analyzed and options for a simultaneous improvement from the thermodynamic, economic and environmental viewpoints are discussed. [ABSTRACT FROM AUTHOR]