分体式空调办公建筑不同设定温度模式对健康的影响研究

The Effect of Different Set Point Temperature Modes on the Health of Office Buildings with Split Air Conditioners

在“双碳”目标背景下,地方政府再次发出办公场所夏季制冷温度设置不低于26℃的通知。为探究不同设定温度模式对健康的影响,本文以26℃为界限,对郑州市和焦作市设定温度≥26℃(实验组)和<26℃(对照组)的分体式空调办公建筑进行现场调研,测量了室内外热环境参数、受试者皮肤温度、室内空气污染物浓度,并调查了受试者的空气质量满意度和空调使用行为状况。研究发现:相比于低设定温度模式,高设定温度模式下受试者对空调的依赖程度更低、暴露的空调环境温度更高、时间更短,对偏热环境的体温调节能力更强。夏季两市办公建筑主要室内空气污染物为CO_(2)和甲醛。高设定温度模式下的室内CO_(2)和甲醛浓度以及甲醛致癌风险均显著小于低设定温度模式,而不同设定温度模式受试者的室内空气质量满意度无显著差异。长期处于低设定温度模式下,会降低人们对室内空气质量的有效感知。从健康和节能的角度出发,应继续加强“办公场所夏季制冷温度设置不低于26℃”的政策引导。研究结果可为夏季分体式空调办公建筑的节能政策推行和室内环境健康问题的解决提供理论依据。

Under the background of the“double-carbon”target,local governments once again issued a notice that the cooling set point temperature of office buildings cannot be lower than 26℃.To explore the effect of different set point temperature modes on health,taking 26℃as the boundary,a field survey was conducted in split air-conditioned office buildings with set point temperatures of≥26℃(experimental group)and<26℃(control group)in Zhengzhou and Jiaozuo,China.Subjective questionnaire and objective environmental parameters were measured simultaneously.The indoor and outdoor environmental parameters(indoor and outdoor air temperature,relative humidity,globe temperature and air velocity),skin temperature of subjects and indoor air pollutant(including CO_(2),formaldehyde and PM2.5)concentration were measured,and the air quality satisfaction and air conditioner usage behavior(air conditioner use modes and air conditioner use time)of people were also investigated.The results showed that subjects in both groups had the same outdoor thermal exposure during the study period,but compared with the H group,the subjects in the L group were exposed to lower temperatures and humidity in the air-conditioned environment.There are two typical air conditioner use modes in office buildings:“turn on when you feel hot”and“turn on when you enter and turn off when you leave”.Compared with the low set point temperature mode,the subjects in the high set point temperature mode were less dependent on air conditioners,were exposed to a shorter time in the air-conditioned environment,and had a stronger thermoregulation ability in the warmer environment.The main indoor pollutants in split air-conditioned office buildings in summer are formaldehyde and CO_(2).The degree of dependence on air conditioners affected the air conditioner use time.Subjects in the low set point temperature mode were more dependent on air conditioners,resulting in subjects in the low set point temperature mode being exposed to the air-conditioned environment for a longer time.This will not only adversely affect people’s thermoregulation ability,making people more addicted to air conditioners in a vicious cycle,but also directly lead to insufficient indoor ventilation,resulting in the concentration of CO_(2)and formaldehyde in the low set point temperature mode being significantly higher than that in the high set point temperature mode.Although the lower air temperature and relative humidity in the low set point temperature mode were not conducive to the volatilization of formaldehyde,it was difficult to disperse indoor formaldehyde due to the strong dependence on air conditioners.Therefore,the formaldehyde concentration was higher,which directly and significantly increased cancer risk.The indoor air quality satisfaction of the high set point temperature mode was affected by the combination of CO_(2)and indoor air temperature,while the indoor air quality satisfaction of the low set point temperature mode was mainly affected by the indoor air temperature.The air quality satisfaction was negatively correlated with the indoor air temperature.In the case of higher indoor pollutant concentration in the low set point temperature mode,since the indoor air temperature of the low set point temperature mode was significantly lower than that of the high set point temperature mode,there was no significant difference in air quality satisfaction between the two modes.It is suspected that people’s air quality perception has long-term adaptability to indoor air temperature and CO_(2).Staying in the low set point temperature mode for a long time reduces people’s sensitivity to CO_(2)concentration,and thus reducing their effective perception of air quality.Indoor temperature affects people’s air quality satisfaction.If indoor air quality is measured by people’s subjective feelings,it may lead to people blindly lowering the set point temperature of air conditioner,which will have adverse effects on health and cause energy waste.Therefore,it is recommended to equip indoor air quality monitoring system for real-time monitoring of air quality,and remind people to take measures in time when it exceeds the standard range.Based on the above analysis of the impact of different set point temperature modes on health,the rationality of the Chinese government’s cooling set point temperature regulation for split air-conditioned office buildings was verified.Therefore,the government of China should continue to strengthen the implementation of the policy that“the cooling set point temperature of offices in summer cannot be less than 26℃”.Encouraging people to save energy is not as good as promoting health,so it is suggested that the state should increase the publicity of the negative effects of low set point temperature on health and guide people to adopt the high set point temperature mode.The research results can provide a theoretical basis for implementing the energy-saving policy of split air-conditioned office buildings and solving indoor environmental health problems in summer.