Abstract
The development of a new index describing complex influence of air temperature, air humidity and wind on the human body was finished in 2009. Development of UTCI was initiated in the frame of a new ISB (International Society of Biometeorology) work group (Commission 6) at the turn of the millenium already, in 2003 this research was converted into a new action in the frame of European projects COST, concretely COST 730.
The new index UTCI is based on a study of human body surface radiation and thermal balance namely and consequently on an evaluation of thermal comfort/discomfort. This index is expressed as an equivalent temperature (in degrees Celsius).
The UTCI development was determined by specifications that was uniquely between hundreds of similar indices. The most of these was designed empirically without an own physical and physiological principle of the influence on the human body.
These indices combined only two of three fornamed meteorological parameters frequently, air temperature with air humidity for a warm part and air temperature with wind for a cold part of a year. Mainly these empirically based indices was applicable to a given climatical limited region.
Other indices was constructed on a physiological basis markedly but these ones was applicable to a research or an ex-post evaluation because the markedly individual characteristics input to calculations (clothing, physical activity etc.). The ISB Commission 6 imposed next requirments on the UTCI from the outset: a global and yearlong validity, a complying with a physiology of the influence on the human organism and a practicability in the day-to-day routine.
It means UTCI has to be calculated from routinely measured meteorological parameters only. Because these parameters are forecastable in meteorology UTCI may become a base of a thermal comfort/discomfort representation in a next biometeorological forecast version.
But this step cannot be executed without a testing of new index properties.