Indoor Air Quality
Understanding IAQ Metrics: AQI, TVOC, PM2.5, PM10, CO₂ & HCHO
Introduction
Indoor air is something we depend on every moment, yet we rarely think about what it actually contains. Homes, offices, schools, and hospitals may look clean, but the air inside them can hold invisible pollutants that slowly affect health and comfort. This is where Indoor Air Quality (IAQ) metrics become important.
IAQ metrics are measurements that help us understand what is present in the air we breathe indoors. They turn invisible air conditions into clear numbers, making it easier to know whether the air is safe or needs improvement. By learning about these metrics, people can make better decisions to protect health and create healthier indoor spaces.
What Are IAQ Metrics?
IAQ metrics are indicators used to measure different types of air pollutants and conditions inside a building. Each metric focuses on a specific element, such as gases, chemical vapors, or tiny particles floating in the air.
These measurements help answer important questions:
- Is the air clean enough to breathe comfortably?
- Is fresh air entering the space properly?
- Are there harmful particles or gases building up over time?
Key IAQ Parameters and Their Safe Limits
Each IAQ parameter measures a different part of air quality. The table below explains what each parameter means, its recommended safe limit, and what can happen when levels go too high.
| Parameter | Description | Recommended Safe limit | Health Isuues | |
| PM 10 | Larger dust particles | ≤ 15 µg/m³ (Annual – WHO)
≤ 45 µg/m³ (24-hr – WHO) | Coughing, throat irritation, allergy symptoms | |
| CO2 | Ventilation and fresh air level | 400–800 ppm: Ideal
≤ 1000 ppm: Acceptable | Sleepiness, poor focus, headaches, discomfort | |
| TVOC | Chemical gases from products | < 300 µg/m³: Good
300–500 µg/m³: Acceptable | Eye and throat irritation, headaches, nausea | |
| HCHO | Chemical from furniture & materials | ≤ 0.1 mg/m³ (0.08 ppm – WHO)
Preferred < 0.05 ppm | Eye irritation, breathing discomfort, long-term health risks |
Why These IAQ Metrics Matter
Each of these values plays a role in how people feel indoors. When even one parameter goes beyond its safe limit, comfort can drop quickly. People may feel tired, distracted, or uncomfortable without knowing why.
Long-term exposure to poor air quality can slowly affect breathing, focus, and overall well-being. That is why understanding and tracking these metrics together—not individually—is important.
Why Continuous IAQ Monitoring Is Important
Indoor air quality changes throughout the day. More people in a room, closed windows, meetings, or weather conditions can quickly affect air quality.
Continuous monitoring helps by:
- Tracking air quality in real time
- Showing when values cross safe limits
- Helping improve ventilation decisions
- Preventing discomfort before it starts
Benefits of Using ESPM SENSE IAQ Monitors
Modern monitoring systems make air quality easy to understand. ESPMSENSE Indoor Air Quality Monitoring Solutions continuously measure all key IAQ parameters such as AQI, PM2.5, PM10, CO₂, TVOC, and HCHO.
How ESPMSENSE Helps:
- Real-time tracking of all major IAQ metrics
- Instant alerts when air quality drops
- Clear data for better ventilation and comfort control
- Suitable for offices, homes, schools, hospitals, and public spaces
Conclusion
Indoor air quality affects everyone, every day—even when we don’t notice it. IAQ metrics like AQI, PM2.5, PM10, CO₂, TVOC, and HCHO help us understand what is happening in the air around us and whether it is safe.
By knowing the limits and monitoring them continuously, indoor spaces can stay healthier, more comfortable, and more productive.
With ESPMSENSE, clean air is no longer a guess—it becomes a measurable part of a healthy indoor environment.