Fanger's approach (which is a part of ISO 7730) to computing zones of thermal comfort is an iterative technique, thus it can be said that it's computationally expensive. Does anybody know if there is a closed-form approximation to Fanger's algorithm? (There seems it is, according to some HVAC producers' documentation, but the exact formulae weren't published, or at least I wasn't able to find them on the Internet or my library.)
Another question: can anybody give pointers to PD (draught) calculation? The literature is incredibly sparse on this, and any help would be appreciated. My main problem is to discover how to calculate the so-called "local turbulence intensity", needed to calculate final PD value. Thanks in advance.