The exhaust air window (EAW) can be regarded as a combination of exhaust air heat recovery unit and window system. The window can locally and directly utilize the exhaust air from each air-conditioned room to reduce the heat loss/gain through window. However, condensation may occur at the internal glazing surface of EAW in winter. To avoid the condensation risk of EAW, some prevention measures were proposed and estimated. In this study, a two-dimensional zonal model of EAW was established to calculate its temperature distribution, and to further identify whether condensation will occur under different boundary conditions. The calculated results were compared with the measured data for verifying the accuracy and reliability of model. A sensitivity analysis was conducted to identify the effects of indoor air temperature and relative humidity, exhaust airflow velocity, and adding a low-e coating on prevention of condensation in winter. The results indicated that adding a low-e coating or decreasing the indoor relative humidity can effectively reduce the critical outdoor temperature of condensation and prevent the occurrence of condensation within the EAW. It was estimated that even under the outdoor air temperature of −20 °C, condensation risk can be avoided by employing a low-e glazing.

排气窗（EAW）可以看作是排气热回收单元和窗系统的组合。窗户可以在本地直接利用来自每个空调房间的废气，以减少通过窗户的热量损失/增加。但是，冬季EAW的内部玻璃表面可能会发生凝结。为了避免EAW的凝结风险，提出并估算了一些预防措施。在这项研究中，建立了EAW的二维区域模型来计算其温度分布，并进一步确定在不同边界条件下是否会发生冷凝。将计算结果与实测数据进行比较，以验证模型的准确性和可靠性。进行了敏感性分析，以确定室内空气温度和相对湿度的影响，排出气流速度，并添加低辐射涂层以防止冬季结露。结果表明，添加低辐射涂层或降低室内相对湿度可以有效降低室外冷凝水的临界温度，并防止EAW内部发生冷凝水。据估计，即使在室外空气温度为-20°C的情况下，使用低辐射玻璃也可以避免凝结的风险。