What is Indoor Air Quality (IAQ)?
Indoor Air Quality (IAQ) refers to the cleanliness of air inside buildings and its impact on occupant health and comfort. Studies indicate that indoor air can be 2-5 times more polluted than outdoor air.
Sources of Indoor Air Pollution
- Chemicals: Volatile Organic Compounds (VOCs) from paints and furniture.
- Biological: Mold, fungi, pollen, dust mites.
- Gases: Carbon monoxide (CO), carbon dioxide (CO₂), radon.
- Particulates: Dust, smoke, PM2.5 and PM10 particles.
- Humidity: High or low relative humidity leads to health problems.
Fresh Air Systems
1. ERV/HRV Systems (Energy/Heat Recovery Ventilators)
They draw out polluted air, recover heat or moisture from it before exhausting, and reuse that energy to heat or cool the incoming fresh air.
2. Air Purifiers
Portable or installed units containing multi-stage filters to purify the air.
3. UVGI Systems (Ultraviolet Germicidal Irradiation)
Use ultraviolet light to kill microorganisms (bacteria and viruses).
4. Ionization Systems
Release negative ions that combine with positive particles and deposit them away from the breathing zone.
Types of Air Filters
| Filter Type | MERV | Efficiency | Application |
|---|---|---|---|
| First Stage | 1-4 | <20% | Windows, simple fans |
| Pleated | 5-8 | 20-35% | Homes, small offices |
| Bag Filter | 9-12 | 40-60% | Commercial buildings |
| HEPA | 17-20 | 99.97% | Hospitals, laboratories |
International Standards and Recommendations
- CO₂ level: Should not exceed 1000 parts per million (ppm).
- Relative Humidity (RH): Between 40-60%.
- PM2.5: Less than 35 µg/m³ over 24 hours.
- Air Changes per Hour (ACH): 0.35 per hour for residential buildings.
Tips for Improving Indoor Air Quality
- 🌬️ Increase natural ventilation by opening windows daily.
- 🧹 Clean AC filters monthly and replace them every 3-6 months.
- 🌿 Grow air-purifying plants (Snake plant, Pothos, Fern).
- 💧 Control humidity using dehumidifiers in damp areas.
- 🚫 Prohibit smoking inside buildings.
- 📏 Install sensors to monitor air quality (CO₂, PM2.5, VOC).
💡 Amazing Facts: Humans spend approximately 90% of their time indoors. Improving indoor air quality can increase productivity by 8-11% and reduce sick leave due to illness.
