Heart rate variability at different thermal comfort levels

The mechanism of human thermal comfort is important for building a comfortable and healthy indoor environment. This paper analyzes human heart rate variability (HRV) at different thermal comfort levels and discusses the mechanism of human thermal comfort. A total of 33 subjects were divided in 3 groups. Under air temperatures of 21, 24, 26, 28, 29, and 30°C, the subjects’ electrocardiogram was recorded for 5 min. HRV (the ratio of absolute powers in low- and high-frequency bands, LF/HF ratio) was analyzed. LF/HF at discomfort level were significantly higher than that at comfort level (P < 0.05), despite the same thermal sensation. The results indicate that sympathetic activity plays an important role in subjects’ thermal discomfort and the LF/HF ratio may be used as an indicator for human thermal comfort.

[1]  T. Ikeda,et al.  Altered response in cutaneous sympathetic outflow to mental and thermal stimuli in primary palmoplantar hyperhidrosis. , 1997, Journal of the autonomic nervous system.

[2]  Refrigerating ASHRAE handbook of fundamentals , 1967 .

[3]  Lei Yang,et al.  [Application of heart rate variability in evaluation of mental workload]. , 2005, Zhonghua lao dong wei sheng zhi ye bing za zhi = Zhonghua laodong weisheng zhiyebing zazhi = Chinese journal of industrial hygiene and occupational diseases.

[4]  David S. Goldstein,et al.  Relative contribution of core and skin temperatures to thermal comfort in humans , 2000 .

[5]  M. Turiel,et al.  Power Spectral Analysis of Heart Rate and Arterial Pressure Variabilities as a Marker of Sympatho‐Vagal Interaction in Man and Conscious Dog , 1986, Circulation research.

[6]  Ji Yun Research of the effect of air velocity on thermal comfort , 2003 .

[7]  J. Thayer,et al.  Vagal influence on working memory and attention. , 2003, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[8]  K. Ivanov Subject of temperature control and the main function of thermoregulation of an organism , 1999 .

[9]  I. Biaggioni,et al.  Effect of neurovestibular stimulation on autonomic regulation , 1995, Clinical Autonomic Research.

[10]  I. Kandjov,et al.  Thermal stability of the human body under environmental air conditions , 1998 .

[11]  S. Sharples,et al.  A comparative analysis of short-term and long-term thermal comfort surveys in Iran , 2002 .

[12]  Refrigerating ASHRAE handbook and product directory /published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc , 1977 .

[13]  A. Bronstein,et al.  Effects of caloric stimulation on respiratory frequency and heart rate and blood pressure variability , 2000, Brain Research Bulletin.

[14]  A. Malliani,et al.  Heart rate variability. Standards of measurement, physiological interpretation, and clinical use , 1996 .

[15]  D. Adam,et al.  Assessment of autonomic function in humans by heart rate spectral analysis. , 1985, The American journal of physiology.

[16]  Tri Harso Karyono,et al.  Report on thermal comfort and building energy studies in Jakarta—Indonesia , 2000 .

[17]  A. Malliani,et al.  Cardiovascular Neural Regulation Explored in the Frequency Domain , 1991, Circulation.

[18]  Mohamed B. Gadi A new computer program for the prediction and analysis of human thermal comfort , 2000 .

[19]  T. Mano,et al.  Effect of skin sympathetic response to local or systemic cold exposure on thermoregulatory functions in humans , 2001, Autonomic Neuroscience.

[20]  Gerd Nürnberg,et al.  Heart rate variability A noninvasive approach to measure stress in calves and cows , 2002, Physiology & Behavior.

[21]  Risto Kosonen,et al.  Local thermal sensation and comfort study in a field environment chamber served by displacement ventilation system in the tropics , 2007 .

[22]  Edna Shaviv,et al.  A knowledge based CAAD system for determining thermal comfort design strategies , 1996 .

[23]  Hui Zhang,et al.  Considering individual physiological differences in a human thermal model , 2001 .