Experimental data of impact of outdoor temperature variations on thermal state in experiments using immersive virtual environment

Recent studies have established immersive virtual environments (IVEs) as promising tools for studying human thermal states and human–building interactions. One advantage of using immersive virtual environments is that experiments or data collection can be conducted at any time of the year. However, previous studies have confirmed the potential impact of outdoor temperature variations, such as seasonal variations on human thermal sensation. To the best of our knowledge, no study has looked into the potential impact of variations in outdoor temperatures on experiments using IVE. Thus, this study aimed to determine if different outdoor temperature conditions affected the thermal states in experiments using IVEs. Experiments were conducted using a head mounted display (HMD) in a climate chamber, and the data was analyzed under three temperature ranges. A total of seventy-two people participated in the experiments conducted in two contrasting outdoor temperature conditions, i.e., cold and warm outdoor conditions. The in situ experiments conducted in two cases, i.e., cooling in warm outdoor conditions and heating in cold outdoor conditions, were used as a baseline. The baseline in-situ experiments were then compared with the IVE experiments conducted in four cases, i.e., cooling in warm and cold outdoor conditions and heating in warm and cold outdoor conditions. The selection of cooling in cold outdoor conditions and heating in warm outdoor conditions for IVE experiments is particularly for studying the impact of outdoor temperature variations. Results showed that under the experimental and outdoor temperature conditions, outdoor temperature variations in most cases did not impact the results of IVE experiments, i.e., IVE experiments can replicate a temperature environment for participants compared to the ones in the in situ experiments. In addition, the participant’s thermal sensation vote was found to be a reliable indicator between IVE and in situ settings in all studied conditions. A few significantly different cases were related to thermal comfort, thermal acceptability, and overall skin temperature.

近期研究已证实，沉浸式虚拟环境（Immersive Virtual Environments, IVEs）是探究人体热状态及人与建筑交互的极具潜力的研究工具。沉浸式虚拟环境的一大优势在于，实验或数据采集可在一年中的任意时段开展。然而，既往研究已证实，室外温度波动（如季节变化）会对人体热感觉产生潜在影响。据我们所知，目前尚无研究探讨室外温度波动对沉浸式虚拟环境实验的潜在影响。为此，本研究旨在探究不同室外温度条件是否会对沉浸式虚拟环境实验中的人体热状态产生影响。本研究在气候舱内借助头戴式显示器（Head Mounted Display, HMD）开展实验，并基于三类温度区间对实验数据开展分析。总计72名受试者参与了两种对比鲜明的室外温度条件下的实验，即寒冷室外环境与温暖室外环境。本研究以两种场景下的现场实验作为基准对照：温暖室外环境下的制冷工况，以及寒冷室外环境下的制热工况。随后，将上述基准现场实验与四类场景下的沉浸式虚拟环境实验进行对比：分别为温暖室外环境下的制冷工况、寒冷室外环境下的制冷工况，以及温暖室外环境下的制热工况、寒冷室外环境下的制热工况。本次沉浸式虚拟环境实验选取寒冷室外环境下的制冷工况与温暖室外环境下的制热工况，正是为了探究室外温度波动的影响。研究结果表明，在本次实验设定的实验温度与室外温度条件下，多数场景中室外温度波动并未对沉浸式虚拟环境实验的结果产生显著影响，即相较于现场实验，沉浸式虚拟环境实验能够为受试者复刻出一致的温度环境。此外，在所有研究场景中，受试者的热感觉投票评分均可作为沉浸式虚拟环境实验与现场实验场景间的可靠比对指标。仅少数场景存在显著差异，涉及热舒适、热可接受度以及整体皮肤温度三项指标。