Air Quality Monitors
An indoor air quality monitor shows what is actually in your air, so you know when to ventilate, run a purifier or test further. The most useful readings are PM2.5 particles, carbon dioxide (CO2) as a ventilation indicator, humidity and, in many US regions, radon.
Which sensors matter
- PM2.5: fine particles from smoke, cooking and outdoor pollution. EPA's annual outdoor standard is 9 µg/m³.
- CO2: outdoor air is about 420 ppm. Many guides use around 1,000 ppm indoors as a sign to ventilate. Choose a true NDIR sensor.
- TVOC: a relative signal for chemicals from cleaning products, paint and furniture. Most sensors show trends, not exact amounts.
- Humidity: helps you hold 30% to 50%.
- Radon: requires a dedicated radon sensor or test kit.
Shop Indoor Air Quality Monitors, CO2 Monitors and Radon Detectors.
FAQs
Are home air quality monitors accurate?
Consumer monitors are good at showing trends and spikes, such as smoke or cooking particles and rising CO2 in a closed room. Absolute accuracy varies. NDIR CO2 sensors are generally reliable, low-cost PM2.5 sensors can drift, and TVOC readings are relative. Use them to guide actions, not as lab measurements.
What is a good indoor air quality reading?
As a rough guide: PM2.5 under about 9 µg/m³ on average, in line with EPA's annual outdoor standard; CO2 under about 1,000 ppm; relative humidity of 30% to 50%; and radon below EPA's 4 pCi/L action level, ideally under 2. Short spikes during cooking are normal.
Where should I put an air quality monitor?
Place it in the room where you spend the most time, usually the bedroom or living area, at breathing height and away from windows, vents, kitchens and humidifiers that would skew readings. For radon, place the detector in the lowest lived-in level of the home.