Chang Yufan, Ai Zhengtao, Ye Jinjun, Ma Guochuan
Department of Building Environment and Energy, College of Civil Engineering, Hunan University, Changsha, Hunan, China.
National Center for International Research Collaboration in Building Safety and Environment, Hunan University, Changsha, Hunan, China.
Build Simul. 2023;16(5):667-682. doi: 10.1007/s12273-023-1000-x. Epub 2023 Mar 26.
The present study develops a cost-effectiveness assessment model to analyze the performance of major operational parameters of central HVAC systems in terms of airborne transmission risk, energy consumption, and medical and social cost. A typical multi-zone building model with a central HVAC system is built numerically, and the effect of outdoor air (OA) ratio (from 30% to 100%) and filtration level (MERV 13, MERV 16, and HEPA) are assessed under the conditions of five climate zones in China. Compared with the baseline case with 30% OA and MERV 13 filtration, the airborne transmission risk in zones without infector is negligibly reduced with the increase in OA ratio and the upgrade of filtration level, owing to their slight modification on the equivalent ventilation rate of virus-free air. However, depending on climate zone, a 10% increase in OA ratio results in 12.5%-78.6% and 0.1%-8.6% increase in heating and cooling energy consumption, respectively, while an upgrade of filtration level to MERV 16 and HEPA results in an increase of 0.08%-0.2% and 1.4%-2.6%, respectively. Overall, when compared to the use of 100% OA ratio and HEPA filtration, the application of 30% or 40% OA ratio and MERV 13 filtration would save annually an energy and facility related cost of $29.4 billion in China, though giving an increase of approximately $0.1 billion on medical and social cost from the increased number of confirmed cases. This study provides basic method and information for the formulation of cost-effective operational strategies of HVAC systems coping with the airborne transmission, especially in resource-limited regions.
本研究开发了一种成本效益评估模型，以分析中央暖通空调系统主要运行参数在空气传播风险、能源消耗以及医疗和社会成本方面的表现。通过数值方法构建了一个带有中央暖通空调系统的典型多区域建筑模型，并在中国五个气候区的条件下评估了室外空气（OA）比率（从30%到100%）和过滤水平（MERV 13、MERV 16和高效空气过滤器）的影响。与采用30%室外空气和MERV 13过滤的基线情况相比，在没有感染者的区域，随着室外空气比率的增加和过滤水平的提升，空气传播风险的降低可以忽略不计，这是因为它们对无病毒空气的等效通风率的改变很小。然而，根据气候区的不同，室外空气比率增加10%分别导致供暖和制冷能耗增加12.5%-78.6%和0.1%-8.6%，而将过滤水平提升到MERV 16和高效空气过滤器分别导致能耗增加0.08%-0.2%和1.4%-2.6%。总体而言，与使用100%室外空气比率和高效空气过滤器过滤相比，在中国采用30%或40%室外空气比率和MERV 13过滤每年可节省294亿美元的能源和设施相关成本，尽管确诊病例数增加会使医疗和社会成本增加约1亿美元。本研究为制定应对空气传播的暖通空调系统的成本效益运行策略提供了基本方法和信息，特别是在资源有限的地区。
