Experimental Study On Human Thermal Sensation Based On Skin Temperature

This thesis studies human thermal response,and how it correlates with skin temperature. It intends to quantify human perceptions of thermal conditions,including overall and local thermal sensation in uniform and non-uniform conditions.This thesis presents results from 179 human subject tests and each test lasts from 1.5 to 3.5 hours.To study human response in varies conditions,local bodies of the subjects,including head,chest,back,arm,hand,leg and foot,were independently heated or cooled while the rest of the body was exposed to a warm, neutral or cool environment.Each local part was stimulated as long as 30min,so that each local part experienced the whole process from transient to stable.Human thermal sensation and comfort were surveyed by TSV,TCV every 5min.and meanwhile skin temperatures were collected at 30 to 60 second intervals.From our test,we observed that skin temperature varied from one place to another even if human stayed in uniform conditions.Also,skin temperature variation is larger in cold environment than in neutral or warm environment.Mean skin temperature is usually determined from a series of skin temperature measurements.Within certain limits when overall thermal sensation is between slightly warn and slightly cool,the correlation between mean skin temperature and thermal sensation is close to linear.But beyond those limits,the linear relationship disappears and the relationship approaches the scale limits exponentially. The set point of the skin temperature is the value when sensation is neutral(zero in the thermal sensation vote).We also observed that skin temperature set point varied from one place to another.The highest skin temperature under neutral conditions is found in the head and the lowest skin temperature is found in the foot.Partial correlation analysis showed that local thermal sensation closely related to local skin temperature and then mean skin temperature.Based on these tests,we have developed predictive models of local and overall thermal sensation and comfort in uniform and non-uniform conditions,including overall thermal sensation model,individual difference model for overall thermal sensation,local thermal comfort model for 7 body parts and the relationship between thermal sensation,thermal comfort and thermal acceptability. These models predicted human perception from skin temperature,so their application was not limited by environment and cloth.The models will be useful for designing and evaluating non-uniform and uniform environments in buildings,such as floor air supply system,task-ambient air conditioning,etc.