PangPang ToolsFloor area: 60 m²; height: 2.7 m; target: 4 ACH
Room volume 162 m³; airflow 648 m³/h; 180 L/s60 × 2.7 = 162 m³. Four theoretical room air changes each hour require 162 × 4 = 648 m³/h.
Construction & Electrical
Required ventilation airflow from ACH
About this tool
Air changes per hour (ACH) expresses how many room volumes of air are supplied or exchanged each hour. This tool multiplies floor area by ceiling height to estimate room volume, then multiplies that volume by a target ACH to estimate airflow. It reports both m³/h and L/s for equipment comparisons. You must select the target ACH based on the actual occupancy, use and applicable standards; this calculator does not determine a legally sufficient ventilation rate.
Ventilation & air changes
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Result
Worked examples
Floor area: 35 m²; height: 3 m; target: 6 ACH
Room volume 105 m³; airflow 630 m³/h; 175 L/sA smaller room with a higher target ACH can require comparable airflow; 35 × 3 × 6 = 630 m³/h.
Questions & answers
Does ACH by itself prove adequate fresh-air ventilation?
No. Recirculated airflow and outdoor-air supply are not interchangeable, and occupancy-based or contaminant-based requirements may control the design.
Why might the installed fan need a different rating?
Published fan airflow can change with duct resistance, filters and installation conditions. Verify performance at the relevant static pressure and check air distribution.
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Result
Worked examples
Room length (m): 6, Room width (m): 4, Ceiling height (m): 2.5, Airflow (m³/h): 300
Room volume: 60 m³Using these sample input values gives the first labelled output above. Geometric ACH does not validate ventilation code, infection control or airflow distribution.
Questions & answers
Can I use the default numbers for purchasing or safety certification?
No. Replace the examples with your real values. Geometric ACH does not validate ventilation code, infection control or airflow distribution.