建筑环境学chapter4.1-2 thermal comfortable.ppt

4.2 What is Thermal Comfort? 人环奖试题： 6、夏季潮湿的空气环境导致人体不舒适的原因是（ ） A、高湿导致皮肤湿润度增加带来粘滞感，使人感到不舒适 B、高湿度导致大气压力降低，从而使人感到不适 C、高湿度导致人体热量散不出去，因而使人感到闷热 D、高湿度导致人体的汗出不来，因而使人感到闷热 Body Temperature 体温 Normal body core temperature: 37 oC. We have separate Heat- and Cold-sensors. Heat sensor热感受器 is located in hypothalamus下丘脑 . Signals when temperature is higher than 37 oC. Cold sensors 冷感受器are located in the skin. Send signals when skin temperature is below 34 oC. Heating mechanism: Reduced blood flow减少血液流动. Shivering发抖. Cooling mechanism: Increased blood flow加速血液流动. Sweating (Evaporation)出汗. Perception of Thermal Environment人对热环境的知觉 Heat sensor in Hypothalamus下丘脑send impulses 脉冲when temperature exceeds 37 oC. Cold sensors sends impulses when skin temperature below 34 oC. The bigger temperature difference, the more impulses. If impulses are of same magnitude等量, you feel thermally neutral热中性. If not, you feel cold or warm. The Energy Balance能量平衡 Thermal Comfort can only be maintained when heat produced by metabolism代谢 equals the heat lost from body. S=0 并不一定表示人体处于舒适状态。 各种热量之间许多不同的组合都可以使S=0，即人们会遇到各种不同的热平衡 只有那种人体按正常比例散热的热平衡，才是舒适的 人体正常散热比例“ 对流换热占25~30% 辐射散热占45%~50% 呼吸和无感觉蒸发散热占25~30% 这种处于舒适状态下的人体热平衡，称为人体正常热平衡。 人环奖试题： 在30℃的空气环境中，人体的发热量与在22℃的空气环境中相比（ ） A、更多，因为人体出汗蒸发促进散热 B、更多，因为高温会导致人体代谢率增加 C、更少，因为皮肤与空气的温度减少了 D、变化不大，因为发热量主要取决于人体的活动量 Evaporative heat loss, E 人体蒸发散热量 (a) Respired Vapour Loss, Eres 呼吸散热散湿量 (i) Latent Respiration Heat Loss, Erel 呼吸时的潜热散热量 (ii) Convective or Sensible Respiration Heat Loss, Erec (b) Evaporative Heat Loss from Skin Surface, Esk 皮肤蒸发散热量 (i) Evaporative Heat Loss by Skin Diffusion, Edif 皮肤湿扩散散热量 (ii) Heat Loss due to Regulatory Sweating, Ersw汗液蒸发散热量 E = Eres + Esk = Erel + Erec + Edif + Ersw Predication of Thermal Comfort热舒适的预测 M-W-C-R-E=0 （S=0） developed by Prof. P. O. Fanger (Denmark) Fanger’s comfort equation: f (M, Icl, V, tr, tdb, Ps) = 0 where M = metabolic rate (met) Icl = cloth index (clo) V = air velocity