In this paper, we will focus on the retrofit of the ventilation system setup on the premise of reserving the original VAV system. Therefore, a combination of the existing VAV system and the dedicated outdoor air system (VAV-DOAS) is discussed. Here, the VAV system handles the indoor temperature and humidity without outdoor air supply, while the DOAS handles the indoor air quality with full outdoor air supply. The feasibility and economic analysis of this combined system are discussed by comparing it with the conventional VAV system operated in the multiple spaces equation-based strategy (MSE-V). The experimental results indicate that the presented VAV-DOAS can save 16% and 21% of energy consumption under winter and summer conditions in Dalian, respectively. Furthermore, this paper presents an economic evaluation method that can effectively evaluate the economy of a VAV-DOAS system retrofitted from the VAV system with different air conditioning loads and outdoor airflow demands. The economic analysis result shows that the retrofit system is economically feasible while the system is designed to serve for more than 12 years.

本文将在保留原有VAV系统的前提下，重点对通风系统设置进行改造。因此，讨论了现有 VAV 系统和专用室外新风系统 (VAV-DOAS) 的组合。在这里，VAV 系统在没有室外送风的情况下处理室内温度和湿度，而 DOAS 在完全室外送风的情况下处理室内空气质量。通过与基于多空间方程的策略 (MSE-V) 的常规 VAV 系统进行比较，讨论了该组合系统的可行性和经济性分析。实验结果表明，所提出的 VAV-DOAS 在大连的冬季和夏季条件下分别可以节省 16% 和 21% 的能源消耗。此外，本文提出了一种经济性评价方法，可以有效地评价在不同空调负荷和室外气流需求下由VAV系统改造而成的VAV-DOAS系统的经济性。经济分析结果表明，改造系统在经济上可行，系统设计使用寿命超过12年。