Impact Of Indoor Air Velocity On Physiological Index And Thermal Comfort

In the study field of thermal comfort, a lot of researchers are looking for suitable air velocity within the range of certain temperature through various kinds of experiments. On one hand, in order to avoid the sense of cold draught under lower temperature, Professor Fanger's PMV-PDD index limits the air velocity on the lower range. And on the other hand, other experiments indicate that the air velocity can be paid for the rising of the environment temperature to a certain extent, the environmental maximum temperature may up to 36 ℃, and get the upper limit of the acceptable air velocity in comfort thermal condition. As to Chongqing's climate characteristic of high temperature during summer, air velocity is very important to improve human's thermal comfort. The human went through the long-term adaptation course to survive and multiply in the natural environment, so people have already formed the extremely complicated biologic system, namely people's rhythm. These factors such as body temperature, heartbeat, breathing, blood pressure and endocrine hormone, etc correlate with environment condition. Human and external environment are harmonious. This paper explains thermal comfort theoretical foundation with physics method and summaries the thermal comfort standards of every international community. Human body's temperature regulation function is analyzed in terms of physiology. Body's temperature keeps relatively stable through the internal temperature regulation system, which is made up of temperature regulation centre, the receptor and effect device. Some systemic and comprehensive physiological indices to estimate the indoor thermal environment are proposed, human's thermal adaptation is mentioned. Some factors to influence the human's thermal sensation are analyzed according to the specific climate of Chongqing, and the reasons are probed. The indoor thermal environment is studied with the way of investigation, which is characterized by impersonal. The window opening, air conditioner operating, and so on are analyzed statistically during summer in Chongqing. To find out the impact of air velocity on human body's physiological indices, probe into the relation of thermal environment especially air velocity and the systemic and comprehensive physiology indices(incliding body temperature, pulse, blood pressure, nerve conduction velocity, electroencephalogram and electrocardiogram etc.) ,which is the first time domestic and overseas, physiology testing and questionnaire investigation are made to 20 persons in different indoor environments by changing the temperature and air velocity, so as to confirm the trend and degree of the influence of air velocity to human's thermal comfort and health. On the basis of the existing experiment condition and sample data analysis, the result shows that the air velocity doesn't have significance influence on human blood pressure, electroencephalogram(EEC) and somatosensory evoked potential, etc, that it has extraordinary significance influence to nreve conduction velocity and body temperature , that it has influence on pulse and electrocardiogram, but not remarkable. The influence of the air velocity on thermal comfort is obvious, the people in Chongqing are more forbearing to the draught than other areas because of its mugginess and aquosity.