Indoor Air Quality (IAQ) Calculator

How It Works

Indoor air quality directly affects health, comfort, and cognitive performance. The EPA estimates that indoor air can be 2 to 5 times more polluted than outdoor air. ASHRAE Standard 62.2 sets minimum ventilation rates based on both floor area (building materials off-gas VOCs) and occupancy (people produce CO2 and moisture). Air changes per hour (ACH) measures how many times the entire room volume is replaced with fresh air each hour — kitchens need more because of cooking pollutants. MERV ratings (Minimum Efficiency Reporting Value) range from 1 to 20 and indicate filter effectiveness. MERV 8 catches most dust and pollen. MERV 11 to 13 catches mold spores, pet dander, and fine dust. MERV 16 and above are hospital-grade HEPA equivalents. CADR (Clean Air Delivery Rate) measures how much clean air a purifier produces per minute — you want a CADR that can process your room volume at least twice per hour.