Air Quality Sensor Explained: What Do the Colors Mean?
Modern air purifiers often include built-in air quality sensors that display real-time conditions through indicator lights or digital screens. Understanding what the colors mean helps users make informed decisions about airflow, fan speed, and overall indoor air management.
How Air Quality Sensors Work
Sensors detect particulate concentration (PM2.5 levels) in the air. Based on these measurements, the purifier shows color indicators that represent air quality conditions.
Common Air Quality Colors and Their Meanings
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Blue or Green – Good Air Quality
Low pollutant levels; purifier may switch to low or sleep mode. -
Yellow – Moderate Air Quality
Mild pollutants present; suitable for medium fan speed. -
Red – Poor Air Quality
High particle concentration; purifier increases filtration speed to remove dust, smoke, or allergens.
Why Understanding Colors Matters
Recognizing sensor colors helps you:
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Respond to changes quickly
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Identify pollution sources (cooking, cleaning, outdoor air entering)
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Adjust purifier settings manually if needed
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Monitor long-term air quality trends in your home
Conclusion
Air quality sensor indicators provide a simple and effective way to understand your home’s environment. Knowing what the colors mean allows you to maintain cleaner, healthier indoor air more consistently.