AIR CHANGES PER HOUR | Often abbreviated as ACPH or ACH, is the number of times that the total air volume in a room or space is completely removed and replaced in an hour. It is a measure of how many times the air within a defined space is replace each hour. A higher “ACPH value” corresponds to a better ventilation.
Ventilation rates are normally expressed as a volume rate per person…such as CFM per person. Air change rates are typically used as a rule of thumb in ventilation design. ASHRAE recommends the following “Air Changes Per Hour”:
* Business Offices = 6-8
* Business Lunch Break Rooms = 7-8
* Business Conference rooms = 8-12
* Churches = 8-12
* Public Auditoriums = 12-14
* Restaurants/Bars = 15-20
* Commercial Kitchens/Restrooms 15-30
At Total Comfort Solutions, we get a lot of questions about HVAC calculations and the airflow requirements. In order to best serve our clients, in some situations, we might need to do ventilation calculations for different areas in different industries.
