Human thermal comfort in a HVAC office building located in a humid subtropical climate: field studies vs. analytical approach

Abstract When it comes to thermal comfort in fully air conditioned buildings, Fanger's predictive mean vote/predicted percentage of dissatisfied (PMV/PPD) published in 1970 is the most widely used model to predict and analyse environments. This paper presents thermal comfort data from an office building that operates with a central air-conditioning system (HVAC) located in Florianópolis, a city with humid subtropical climate on the southern coast of Brazil. This paper presents and compares thermal sensation results obtained from field studies (284 participants) against calculated PMV/PPD values based on the ASHRAE 55 (2013) analytical method. Electronic questionnaires were administered simultaneously to instrumental measurements (air temperature, radiant air temperature, air speed and humidity) during 2014. The results showed that, although 91% of the occupants evaluated the environment as thermally comfortable, the mean PPD scored 16% of dissatisfied people. Moreover, results suggested a certain inadequacy of this model to the climate in question, especially when the PMV ranges between ± 0.50, the interval determined as comfortable by ASHRAE 55 (2013).

摘要：在全空调建筑的热舒适研究中，1970年发布的范格尔预测平均热感觉投票（predictive mean vote, PMV）与预测不满意百分比（predicted percentage of dissatisfied, PPD）模型，是当前应用最为广泛的环境热舒适预测与分析模型。本文针对巴西巴西南部海岸湿润亚热带气候城市弗洛里亚诺波利斯的一栋采用集中式暖通空调系统（HVAC）的办公建筑，采集了其热舒适相关数据；并将现场调研（共284名参与者）获取的热感觉评价结果，与基于美国采暖、制冷与空调工程师学会55标准（American Society of Heating, Refrigerating and Air-Conditioning Engineers 55, ASHRAE 55）2013版分析方法计算得到的PMV/PPD值进行对比。2014年期间，研究团队同步开展电子问卷调研与仪器测量工作，测量参数涵盖空气温度、辐射温度、空气流速与空气相对湿度。研究结果表明，尽管91%的建筑使用者认为所处环境热舒适，但平均PPD值对应的不满意人群占比达16%。此外，结果显示该模型对本次研究的气候环境存在一定适配缺陷，尤其当PMV值处于±0.50区间（即ASHRAE 55（2013版）定义的热舒适区间）时，该适配缺陷更为突出。