HVAC engineers

  Fresh Air Requirement in HVAC (Ventilation Basics) Fresh air is essential to maintain indoor air quality (IAQ), comfort, and safety in buildings. Why Fresh Air is Required Removes CO₂ and pollutants Controls odor and humidity Improves occupant health Fresh Air Standards (ASHRAE 62.1 / NBC) Person-Based Office 8-10 L/s/person (17-21 CFM/person) Conference Room 10-15 L/s/person (21-32 CFM/person) Area-Based Office Area 0.3-0.6 CFM/ft² 1.5-3 L/s-m² Conference Room 0.5-1.0 CFM/ft² 2.5-5 L/s-m² Example (Combined Calculation) For an office of 100 m² with 10 persons: Person-based = 100 L/s (≈ 212 CFM) Area-based = 200 L/s (≈ 424 CFM) Final Fresh Air = 200 L/s (≈ 424 CFM) (higher value considered) Methods of Fresh Air Intake Fresh Air Fan (FAF) AHU with mixing box DONATE ERV / HRV Key Point Use both person + area method Select higher value for design Proper ventilation = Healthy + Energy Efficient HVAC System