<HTML><BODY>Hi Jon<br /><br />there is, of course, no single pair of numbers. The distribution highly depends on surroundings, activity rate and clothing level.<br /><br />As CIBSE Guide A (chapter 6.3) states, "between 20 and 60% of the sensible heat emission can be radiant depending on type of clothing, activity, mean radiant temperature and air velocity".<br /><br />The ASHRAE Fundamentals have an extensive chapter on Physiological Principles and Thermal Comfort and give equations for the various heat transfer mechanisms.<br /><br />For "sedentiary office work", I have a (german) source that gives approx. 40 % radiative at 20 °C and approx 32 % radiative at 26 °C office temperatures (with total sensible heat loss of 90 and 70 W, respectively - the total value is approx. 120 W for both temperatures). Interestingly, this source discerns between radiative, conductive and convective. But the conductive part is only approx. 8 - 10 % and is probably !
usually
added to the convective part.<br /><br />Best<br />Achim<br /><br /><br /><br />--------- Original-Nachricht --------<br /> Von: "Jon Hand" <jon@esru.strath.ac.uk><br /> An: "esp-r@lists.strath.ac.uk" <esp-r@lists.strath.ac.uk><br /> Betreff: [esp-r] radiant and convective split for occupants<br /> Datum: 14/12/10 10:23<br /> <br /> <br /> I am updating some documentation about occupants in buildings related to<br /> the radiant and convective split of sensible gains and I find that there are<br /> a number of exemplar models that simply default to 50% radiant. If I look<br /> at the exemplar models that come with EnergyPlus I see most of them<br /> are setting the radiant fraction of occupants to 30% and at least one<br /> paper mentioned 40%.<br /> <br /> A Google search comes up with suggestions for what the sensible<br /> is but mentions of how it is distributed seem to be well hidden. In densely<br /> populated spaces this must have an
impact.<br /> <br /> Does anyone have some or know about ...<br /> a) opinions that they would like to share<br /> b) some references that discuss this<br /> c) some papers that talk about it<br /> <br /> Regards, Jon Hand<br /> _______________________________________________<br /> esp-r mailing list<br /> <a href="mailto:esp-r@lists.strath.ac.uk" class="autolink">esp-r@lists.strath.ac.uk</a><br /> <a href="http://lists.strath.ac.uk/mailman/listinfo/esp-r" target="_blank" class="autolink">http://lists.strath.ac.uk/mailman/listinfo/esp-r</a><br /> <br /> </BODY></HTML>