How many air exchanges per hour should positive mechanical ventilation provide?

Positive mechanical ventilation systems are designed to enhance indoor air quality by removing stale air and introducing fresh air into a building. The recommended number of air exchanges per hour can vary based on the specific application and occupancy, but for spaces that require strong ventilation—such as residential and commercial environments—six air exchanges per hour is a standard target.

This frequency of air exchange is considered ideal for diluting and removing indoor pollutants, moisture, and other contaminants effectively. Ensuring that there are six air changes helps maintain proper ventilation rates recommended by various health and building codes. This helps to limit issues related to indoor air quality and promotes a healthier living or working environment by minimizing airborne viruses, allergens, and other hazardous particles.

Thus, having six air exchanges per hour balances the need for adequate fresh air intake while keeping energy use in check, making it a common standard in many ventilation guidelines.