“Air change rate”指的是空气置换率，也就是单位时间内室内空气中空气污染物的最大允许替换次数。
以下是一个关于Air change rate的英文范文：
Air change rate is an important factor in indoor air quality. It refers to the maximum allowed replacement frequency of air in a room per unit time. A higher air change rate means that more air enters and leaves the room, reducing the concentration of harmful gases and odors. On the other hand, a low air change rate can lead to poor ventilation and result in uncomfortable indoor air quality. Therefore, it is important to consider the air change rate when designing and maintaining indoor environments. In some cases, building codes and standards may specify a minimum air change rate for different types of buildings and occupancies.
空气变化率（Air Change Rate）是指在单位时间内室内空气质量的改变程度。它通常用于描述室内环境的舒适度，例如在室内空气质量、温度、湿度等方面的变化情况。
在英文范文方面，以下是一篇关于空气变化率的范文示例：
标题：Air Change Rate and Its Impact on Indoor Environment
Air change rate is an important indicator that measures the speed at which the air quality in a room changes over time. A high air change rate indicates that the air is being constantly replaced, which can lead to a more comfortable indoor environment with fresh air and reduced pollutants. However, a low air change rate can lead to poor indoor air quality, as it can result in trapped pollutants and moisture buildup.
In our office building, we have implemented a high air change rate of approximately 10 air changes per hour. This ensures that the air quality in the office is constantly refreshed and we are able to maintain a comfortable environment for our employees. However, we also need to ensure that the air quality is monitored regularly to ensure that it remains within an acceptable range.
On the other hand, some buildings may have a low air change rate, which can lead to poor indoor air quality. This can be particularly problematic in enclosed spaces such as classrooms or offices where there is a high concentration of pollutants and moisture buildup. Therefore, it is important to consider the air change rate when designing and maintaining indoor environments to ensure that they are healthy and comfortable for occupants.
“Air change rate”在英文中通常指的是空气置换率，也就是单位时间内室内空气置换的速率。
在英文范文中的具体使用，会根据实际情况有所变化，例如在一些涉及到室内环境控制的场合，就可能会使用到air change rate这个概念。