Study On The Difference Of Indoor Human Thermal Comfort Under Different Lighting Conditions

In recent years,the development and utilization of urban underground space has become a major trend around the world,but at the same time,the problem of human comfort in underground space has become more and more prominent.At present,the research on the comfort of the human body in the underground space mainly focuses on public buildings such as subways and underground shopping malls,and there is less research on the thermal comfort and thermal sensation of the human body when the human body is in a sitting office state in the underground building.The characteristics of underground buildings are different from those of above-ground buildings,but at present,the design and construction of the indoor environment of underground buildings are often based on the relevant design rules and experience of above-ground buildings,which makes it difficult for the human body to achieve a satisfactory state when they are in underground buildings.Therefore,it is necessary to study the subjective reactions and physiological parameters such as thermal sensation and thermal comfort when the human body sits and works in underground and above-ground buildings,and it can also provide a certain reference for the indoor environment design of underground buildings.From the end of 2021 to the beginning of January 2022,this paper uses the existing laboratory to simulate above-ground and underground rooms,and creates indoor thermal environments(18℃,20 ℃,22℃,24 ℃)at different operating temperatures in the laboratory.By summoning subjects to conduct on-site experiments,collecting subjective evaluations such as thermal response votes of the human body in underground and above-ground rooms,and physiological parameters of the human body during the experiment,etc.,analyze the collected data,and study the human body in underground rooms and underground rooms.Differences exist in subjective assessments and physiological parameters of the room.The results of the study showed that there were certain differences in the subjective evaluations and physiological parameters of the subjects when they were in the above-ground and underground rooms.First,in a cooler indoor environment,subjects’ subjective thermal responses differed significantly between underground and above-ground rooms.Under the condition of the same indoor operating temperature,the average thermal sensation vote value,average thermal comfort vote value and thermal acceptability of subjects in the underground room are lower,and the lower the indoor operating temperature,the more significant the difference is.When the indoor operating temperature is 18℃,the average thermal sensation and the average thermal comfort vote of the human body in the underground room are 0.3 and 0.57 lower than those in the above-ground room,respectively.By increasing the indoor operating temperature,the human body can be significantly reduced in the above-ground and underground rooms.difference in thermal response.In addition,through regression analysis of various steady-state thermal response parameters of the human body,it is found that when the thermal sensation of the human body is on the cold side or thermal neutrality,and the thermal sensation is the same,compared with the room above ground,the human body in the underground room is more stable.The thermal comfort is worse and the thermal acceptability is lower.When the human body is in a thermoneutral state,the thermal comfort value and thermal acceptability in the underground room are 0.204 and 0.24 lower than those in the above-ground room,respectively;in the same thermal comfort value In other cases,the thermal acceptability of the human body in an underground room is also lower.Second,subjects rated the indoor environment of the basement room lower overall.When the indoor operating temperature is the same,even if the relative humidity difference between the above-ground and underground rooms is controlled within a small range,the human body is more likely to feel damp when in the underground room.35.5% of the subjects in the room felt damp,while only 7.4% of the subjects in the above-ground room felt damp,and the subjects were prone to depression and drowsiness when they were in the underground room.In addition,when subjects were more prone to sick building syndrome in underground rooms,and the lower the indoor operating temperature,most of the symptoms became more obvious.As the indoor operating temperature increased,the proportion of subjects with sick building syndrome continued to decline.And most subjects with Sick Building Syndrome had their symptoms alleviated to some extent.These negative subjective evaluations also corresponded to their worse performance in basement rooms,lower self-ratings of work performance,and reluctance to work in such an indoor environment.Finally,there were differences in the physiological parameters of the subjects.Under the same indoor operating temperature,there was no significant difference in the mean skin temperature of the subjects,but the blood oxygen concentration of the subjects was lower in the underground room.When the indoor operating temperature was 18 °C,the blood oxygen concentration of the subjects was lower.There was a significant difference in oxygen concentration between the above-ground and underground rooms.The blood oxygen concentration in the underground room was0.44% lower than that in the above-ground room,indicating that the subjects’ respiratory system was affected.The pulse rate was higher,which was 3.2 or more higher than the average pulse rate in the above-ground room under each working condition,indicating that the subjects had a certain degree of depression and anxiety when they were in the underground room.In addition,through regression analysis on the human body’s steady-state thermal sensation voting and average skin temperature,it is found that when the human body’s average skin temperature is less than 33°C,the human body’s thermal sensation value is higher when the human body is in the above-ground room,that is,it feels at the same skin temperature.Relatively warmer,and the opposite is true when the average skin temperature of the human body is greater than 33 °C,and the thermal sensation value of the human body is higher when the human body is in the ground room.The research results of this paper can provide a certain reference for the design and improvement of the indoor environment of underground buildings,thereby creating a more comfortable indoor environment for people living and working in underground buildings.