Thermal equation, Fanger

Research on the combined effects of textiles indoors would require an environmentally controlled room in which heat flux and the six variables important for thermal comfort (Fanger s equation) could be monitored and measured with appropriate instrumentation. The overall effect of textiles indoors could then be translated into their efficiency for providing thermal comfort at conservative thermostat settings. 

Environmental Conditions. The last area of discussion concerns those studies that emphasize environmental factors indoors and their interrelationship with clothing. Fanger s multivariate equation for predicting thermal comfort indoors, which he defines as thermal neutrality, is based on statistical analysis of 1,300 Danish and American subjects and consists of six parameters metabolic activity of occupants, clothing insulative value (clo), air temperature, mean radiant temperature, relative humidity, and air velocity ( 8, TjO An instrument based m these parameters and the statistical analysis is available (Figure 2) a reading for the parameters is integrated and the percent of occupants satisfied with the thermal environment is displayed. 

For clothing assemblies, more information is needed on the insulative (clo) values of representative fiber/fabric combinations available to consumers. These clo values may then be related to thermal comfort at conservative thermostat temperatures using instruments such as the Comfytest, which has the capability of evaluating the six parameters of Fanger s thermal comfort equation (7U). 

The human heat balance equation is used to describe the balance of the thermal system of a person. There have been many models proposed, the aims of which are to show the balance of the metabolic heat production—the metabolic energy produced (M) minus the energy of mechanical work done (W)—and the sum of all the heat loss systems, including the rate of heat storage (i.e., whether the system is heating up or cooling down) (Fanger, 1972 Parsons, 2002). 

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