Standard Air Changes per Hour (ACH) – Reference Guide
Commercial, Institutional & Industrial Facilities
This page provides typical Air Changes per Hour (ACH) reference values for spaces commonly encountered in commercial, institutional, and industrial buildings .
The intent is to support:
concept HVAC design,
BOQ preparation,
preliminary equipment sizing,
ventilation strategy alignment during tender and procurement stages.
Values shown are industry-accepted reference ranges , aligned with guidance from ASHRAE .local codes, fire authority requirements, and process-specific conditions .
Residential & Light Commercial Areas
Application Area Typical Recommended ACH Residential basements 3 – 4 Bedrooms 5 – 6 Living / family rooms 6 – 8 Residential kitchens 7 – 8 Bathrooms / toilets 6 – 7 Laundry rooms 8 – 9
Offices & Administrative Buildings
Application Area Typical Recommended ACH Business offices (open plan) 6 – 8 Conference / meeting rooms 8 – 12 Break rooms / pantry 7 – 8 Copy / print rooms 10 – 12 Medical / examination offices 9 – 10 IT / computer rooms (non-critical) 10 – 14 Smoking areas (where permitted) 13 – 15
Restaurants, Canteens & Food Facilities
Application Area Typical Recommended ACH Dining areas 8 – 10 Food courts 8 – 12 Commercial kitchens 14 – 18 Bars & beverage areas 15 – 20 Food staging / preparation rooms 10 – 12
Public Buildings & Assembly Spaces
Application Area Typical Recommended ACH Corridors / hallways 6 – 8 Retail stores 6 – 10 Foyers / lobbies 8 – 10 Auditoriums / theatres 12 – 14 Banquet halls 6 – 10 Ballrooms 6 – 12 Places of worship 8 – 12 Public restrooms 10 – 12
Educational Facilities
Application Area Typical Recommended ACH Classrooms 6 – 8 Laboratories 8 – 12 Libraries 6 – 8 Staff rooms 6 – 8 School / college toilets 10 – 12
Industrial, Utility & Service Areas
Application Area Typical Recommended ACH Basement / enclosed parking 6 – 10 DG rooms / generator rooms 12 – 20 Pump rooms 6 – 10 Electrical rooms / switchgear rooms 6 – 10 Battery rooms (UPS / ESS) 10 – 20 Machine rooms / plant rooms 10 – 15 Compressor rooms 10 – 15 Workshops / fabrication areas 8 – 12 Warehouses (non-hazardous) 4 – 6
Sewage & Wastewater Facilities
Application Area Typical Recommended ACH STP blower rooms 10 – 15 STP pump rooms 10 – 15 Sludge handling rooms 12 – 20 Chemical dosing / storage rooms 10 – 15
Short Technical Notes (Design & Procurement Use)
ACH values represent air volume turnover , not indoor air quality alone. Occupancy-based ventilation must be checked separately.
High-risk areas (DG rooms, battery rooms, kitchens, STP areas) are exhaust-driven spaces , not comfort-driven spaces.
Basement parking ventilation is commonly governed by CO sensor logic and fire authority requirements , not fixed ACH alone.
High ceiling spaces require air distribution effectiveness evaluation ; ACH alone may be misleading.
Smoke exhaust and fire ventilation systems are separate from normal ventilation and must meet fire code criteria.
For equipment rooms, manufacturer temperature limits often govern final airflow selection.
