Buildings are more and more airtight in order to meet the energy performance requirements of national regulations. To provide appropriate air quality for occupants’ energy conscious ventilation systems are installed. However, in residential buildings natural ventilation methods are widely used. Because of the COVID-19 pandemic lots of people working initially in offices suddenly started to perform their activities at home, so they worked in so called home-office regime. Thus, rooms without mechanical ventilation were transformed from one day to other in offices. However, appropriate indoor air quality has to be provided since the human performance strongly depends by the CO₂ concentration in the air. The aim of this research was to analyse and compare different natural aeration methods which can be adopted in this cases from energy point of view. A residential building built in 2014 was taken as an example, having gas filled triple glazed windows Class 3. The air change rates were determined at different temperatures having the window fully opened or tilted. Measurements were performed with and without occupants in the room in order to validate the results obtained from CO₂ balance equation. The energy demand for heating up the fresh air was analysed. It was shown that up to 18% energy saving may be obtained choosing properly the aeration strategy. The paper draws the attention of stakeholders on the fact that changing the function of a room can lead to significant increase of energy consumption, which can be mitigated controlling properly the aeration process.

为了满足国家法规对能源性能的要求，建筑物越来越密闭。为了为乘员的能量敏感型通风系统提供适当的空气质量。然而，在住宅建筑物中，自然通风方法被广泛使用。由于COVID-19大流行，许多最初在办公室工作的人突然开始在家中进行活动，因此他们在所谓的家庭办公室体制中工作。因此，没有机械通风的房间从一天到另一天在办公室中转换。但是，由于人类的表现很大程度上取决于CO ₂，因此必须提供适当的室内空气质量。空气中的浓度。这项研究的目的是从能源的角度分析和比较在这种情况下可以采用的不同自然曝气方法。以2014年建造的一栋居民楼为例，该建筑物的气体填充了三级三层玻璃窗。在窗户完全打开或倾斜的不同温度下确定空气变化率。为了确认从CO ₂获得的结果，在房间中有无乘员的情况下进行了测量平衡方程。分析了加热新鲜空气的能源需求。结果表明，正确选择曝气策略可以节省多达18％的能源。本文引起了利益相关者的关注，即改变房间的功能会导致能耗显着增加，而这可以通过适当控制通气过程来缓解。