Human-Centered Product–Interior Design Optimization: Linking Adjustable Furniture, Indoor Environmental Quality, and User Comfort in Small Workspaces

Small workspaces function as integrated systems, yet ergonomic furniture and indoor environmental conditions are typically evaluated in isolation. This study investigates the independent and combined impacts of adjustable furniture and optimized indoor environmental quality (IEQ) on user comfort, physical well-being, and work performance. We conducted a multicenter, assessor-blinded 2 × 2 factorial controlled trial across six office sites involving 240 participants. Subjects were equally assigned to a four-week intervention of fixed furniture with basic IEQ, adjustable furniture with basic IEQ, fixed furniture with optimized IEQ, or an integrated condition featuring both. The furniture intervention utilized individually configured sit-stand desks, while IEQ optimization targeted precise thermal, ventilation, lighting, acoustic, and particulate metrics. At week four, the integrated condition yielded the highest overall comfort scores (5.62 ± 0.53), significantly outperforming the fixed-basic baseline (3.99 ± 0.60). Analysis revealed a positive interaction between the two interventions. Adjustable furniture distinctly enhanced anthropometric fit and posture comfort while reducing neck and lower-back discomfort. Conversely, optimized IEQ primarily improved environmental comfort, task speed, perceived productivity, and mitigated mental fatigue. The integrated approach provided additive benefits for task accuracy and workspace satisfaction, although neither intervention significantly altered creativity. These findings demonstrate that physical adjustability and environmental quality address distinct, complementary facets of the occupational experience. Ultimately, human-centered workspace design must transcend isolated component selection, synergistically combining individual workstation fit with comprehensive IEQ management to maximize occupant comfort and functional performance.小型办公空间虽可作为集成系统运行，但人体工学家具与室内环境条件的评估通常各自独立进行。本研究旨在探究可调节家具与优化后室内环境质量（Indoor Environmental Quality, IEQ）分别及联合作用对使用者舒适度、身体健康状况与工作绩效的影响。我们在六个办公场地开展了多中心、评估者单盲的2×2析因对照试验，共招募240名受试者。受试者被平均分配至四组为期四周的干预方案：固定家具搭配基础IEQ组、可调节家具搭配基础IEQ组、固定家具搭配优化IEQ组，以及同时采用两项优化措施的集成方案组。家具干预采用个性化配置的升降桌，而IEQ优化则针对精准的热环境、通风、照明、声学及颗粒物相关指标进行调控。干预四周后，集成方案组的整体舒适度评分最高（5.62 ± 0.53），显著优于固定家具-基础IEQ的基线组（3.99 ± 0.60）。分析结果显示两项干预措施间存在正向交互作用。可调节家具可显著提升人体工学适配性与姿势舒适度，同时缓解颈部与下背部不适。反之，优化IEQ则主要改善环境舒适度、任务完成速度、感知生产力，并减轻精神疲劳。集成方案则为任务准确率与办公空间满意度带来了额外增益，但两项单独干预均未对创造力产生显著影响。上述研究结果表明，物理调节性与环境质量分别针对办公体验中相互补充的不同维度。最终，以人为中心的办公空间设计不应局限于孤立的组件选择，而应协同整合个性化工作站适配与全面的IEQ管理，以最大化使用者的舒适度与工作效能。