Field Study Of Thermal Comfort In Sleeping Environment In Winter At Rural Houses With Kang In Severe Cold Region

As people pay more attention to the quality of sleep,thermal comfort in sleep environment starts to become a hot spot of concern recently.In the northeast of China,it is severe cold in winter.What's more,the heating forms used in the rural areas are relatively backward.The indoor air temperature,especially the low temperature at night,has a certain influence on the health of the local villagers.Combined with this reality,it is necessary to carry out field researches on thermal comfort in rural houses in the severe cold regions.The research is conducted by a comprehensive integrated way on the subjective and objective aspects.First a census of the sleeping environment of rural houses in severe cold areas is carried out.Then the research on the key samples follows.The test samples are from Helen City,Heilongjiang Province.29 houses are selected first.A total of 58 subjects are surveyed.The environmental parameters in the sleep environment are tested continuously.The subjective investigation of the thermal comfort and sleep quality is carried out.Then,on the basis of the survey,4representative subjects are selected from 2 families to carry out a 5-day tracking test,with the continuous test of the skin temperature of the subjects during the sleep process.The results showed that the indoor air temperature in sleeping environment in winter at rural houses in severe cold region is 12.8?,much lower than that in urban residential buildings with central heating system.The average relative humidity is50.4%,and the average indoor air velocity is 0.07m/s,which are in the thermal comfort zone.The average surface temperature of Kang is 34.2?,much higher than the ambient temperature.The average skin temperature of the subjects is relatively concentrated.And 80% of the average skin temperature was within 32.7~35.2 C,with an average of34.3 C.In spite of the low indoor air temperature in sleep environment in winter at rural houses,94.8% of the subjects are acceptable to the environment,and 79.3% of the subjects feel comfortable with the environment.It is found that there is a linear relationship between the globe temperature and the air temperature in sleeping environment in winter at rural houses in severe cold region.What's more,the operation temperature and the indoor air temperature both show strong connections with the surface temperature of the Kang.Sleeping thermal environment has a direct effect on the sleep quality of subjects.Subjects in the cold environment(8.8?),moderate environment(13.4?),warm environment(17.8?)have different sleep quality.Subjects in the moderate environment have the best sleep quality.However,subjects in the moderate environment have the worst sleep quality.In the sleeping environment in winter at rural houses in severe cold region,there is a positive correlation between the skin temperature and the ambient temperature.Compared with the ambient temperature,the average skin temperature has a more direct effect on human thermal sensation.Even if the temperature of the environment fluctuates in a large range,the subjects can still maintain a good thermal sensation as long as the skin temperature being stable in the comfortable range.In the sleeping environment in winter at rural houses in severe cold region,the operation temperature is the most suitable evaluation index for the thermal comfort compared with the other environmental factors.The operation temperature can be used as an input variable to establish the thermal comfort measurement model of the sleeping environment in winter at rural houses in severe cold region.The prediction model of thermal comfort can be modified by introducing the expectation factor to make it more suitable for the sleeping environment in winter at rural houses in severe cold region.