Provincial Engineering Laboratory of Hunan for the Technologies of Building Environment Control, University of South China, Hengyang 421001, China; School of Energy Science and Engineering, Central South University, Changsha 410083, China.
Provincial Engineering Laboratory of Hunan for the Technologies of Building Environment Control, University of South China, Hengyang 421001, China; Collaborative Innovation Center for Building Energy-conservation and Environment Control, Hunan University of Technology, Zhuzhou 412001, China.
Sci Total Environ. 2018 Mar;616-617:1124-1133. doi: 10.1016/j.scitotenv.2017.10.208. Epub 2017 Oct 31.
In order to study the human thermal comfort under different environments, the electrocardiogram (ECG) data of 6 subjects were recorded continuously under 60 environments composed by different air temperature, relative humidity and air speed that were created by an environmental chamber. Based on the ECG data, the frequency-domain method was adopted to obtain the heart rate variability (HRV) results. Among the HRV indices, the ratio of the low frequency power and high frequency power of the HRV analysis results (LF/HF), which reflects the balance of the autonomic nervous system, was selected as an indicator of the thermal comfort in the study. And the effects of air temperature, relative humidity and air speed on LF/HF were scrutinized. Meanwhile, a questionnaire survey was conducted during the experiment to evaluate the thermal comfort of the subjects. And the relationships between mean LF/HF and thermal sensation, mean thermal comfort were established based on the survey. The results showed that different LF/HF was observed under different environments, and that the air temperature had the most significant effects on LF/HF. The changes in the air temperature could easily lead to the excitation of the sympathetic nerve that could promote the activities of the thermoregulatory effectors thus thermal discomfort. Additionally, the fitting curves illustrating the relationships between LF/HF and thermal sensation and thermal comfort showed that the higher LF/HF yielded thermal discomfort, while the low LF/HF indicated a thermally acceptable state.
为了研究不同环境下人体的热舒适度，对 6 名受试者在环境舱创造的 60 种不同的温度、相对湿度和风速环境下连续记录了心电图（ECG）数据。基于 ECG 数据，采用频域法获得了心率变异性（HRV）的结果。在 HRV 指标中，选择 HRV 分析结果的低频功率与高频功率之比（LF/HF）作为研究中热舒适度的指标，反映自主神经系统的平衡。考察了空气温度、相对湿度和空气速度对 LF/HF 的影响。同时，在实验过程中进行了问卷调查，以评估受试者的热舒适度。并根据调查结果建立了平均 LF/HF 与热感觉、平均热舒适度之间的关系。结果表明，不同环境下观察到不同的 LF/HF，空气温度对 LF/HF 的影响最显著。空气温度的变化容易导致交感神经兴奋，促进体温调节效应器的活动，从而引起热不适。此外，LF/HF 与热感觉和热舒适度之间的关系拟合曲线表明，较高的 LF/HF 会产生热不适，而较低的 LF/HF 则表示热可接受状态。
