What does ACH represent in building analysis?

ACH stands for Air Changes Per Hour, which is a critical metric in building analysis used to assess the ventilation rate within a space. This measurement indicates how many times the air within a defined space is replaced with outside air in one hour. A higher ACH value suggests better ventilation, which is essential for maintaining indoor air quality by reducing contaminants and ensuring adequate oxygen levels.

In building analysis, understanding ACH helps professionals evaluate the effectiveness of heating, ventilation, and air conditioning (HVAC) systems. It is vital for achieving energy efficiency and comfort within a building while preventing issues related to stale air or excessive humidity. Monitoring and optimizing ACH can lead to improved energy performance and indoor environmental quality, making it an important aspect of building performance assessments.