Air Quality Monitors & Carbon Dioxide (CO2) Detectors

What is a CO2 sensor, and how does it work?

A CO2 sensor is a device that measures the concentration of carbon dioxide in the air. These sensors use infrared technology to detect CO2 molecules and display readings in parts per million (ppm). When CO2 levels rise above safe thresholds, the sensor alerts you with visual or audible warnings.

Most CO2 sensors include additional features, such as temperature and humidity monitoring. This provides a comprehensive view of your indoor environment. Digital displays show real-time readings, making it easy to track air quality throughout the day.

Why do you need a CO2 sensor in your home or workplace?

Carbon dioxide builds up quickly in enclosed spaces. Every person exhales approximately 1 kilogram of CO2 daily. Without proper ventilation, levels can reach unsafe concentrations within a matter of hours.

CO2 levels above 1000ppm indicate poor ventilation. At 5000ppm, you'll experience drowsiness and stuffiness. Levels exceeding 10,000ppm become immediately dangerous. A CO2 sensor warns you before these thresholds are reached.

Schools, offices, and meeting rooms benefit most from CO2 monitoring. These spaces often have a high density of people in relatively small areas. Poor air quality reduces learning ability and work performance by up to 15%.

What CO2 levels are considered safe?

Outdoor air typically contains 400-420ppm of CO2. Indoor levels should remain below 1000 ppm for optimal health and comfort. Here's what different readings mean:

400-800ppm: Excellent air quality
800-1000ppm: Good air quality, but consider ventilation
1000-1500ppm: Moderate air quality, ventilation needed
1500-5000ppm: Poor air quality, immediate action required
Above 5000ppm: Dangerous levels, evacuate the area

Regular monitoring helps you maintain safe levels through proper ventilation timing.

How accurate are CO2 sensors?

Professional-grade CO2 sensors achieve accuracy within ±30ppm. This precision level meets health and safety standards for most applications. Cheaper consumer models may have accuracy ranges of ±50-100ppm, which is still adequate for general monitoring.

Sensor accuracy depends on calibration and maintenance. Most units require annual calibration to maintain precision. Some models include automatic calibration features that adjust readings based on outdoor air reference points.

Where should a CO2 sensor be placed?

Position your CO2 sensor at breathing height, typically 1.5 to 2 metres from the floor. Avoid placing units near windows, doors, or air vents, as this can skew readings due to the influence of fresh air or drafts.

In offices, place sensors in occupied areas rather than corridors. Bedrooms benefit from sensors positioned away from the bed to avoid false readings from exhaled breath. Meeting rooms should have sensors centrally located for representative measurements.

Consider multiple sensors for larger spaces. CO2 levels can vary significantly across different areas of the same room.

Can CO2 sensors detect other gases?

Standard CO2 sensors detect only carbon dioxide. However, many air quality monitors include additional sensors for other harmful gases. These multi-gas detectors can measure:

• Carbon monoxide (CO)
• Volatile organic compounds (VOCs)
• Particulate matter (PM2.5 and PM10)
• Nitrogen dioxide (NO2)
• Formaldehyde

This comprehensive monitoring approach offers enhanced protection and a deeper understanding of your indoor air quality.

How often should you calibrate your CO2 sensor?

Most CO2 sensors need calibration every 12 months to maintain accuracy. Some units feature automatic baseline calibration, which adjusts readings weekly based on the lowest CO2 levels detected.

Manual calibration involves exposing the sensor to known CO2 concentrations, typically 400 ppm of outdoor air. Professional calibration services ensure optimal performance for critical applications, such as schools and hospitals.

Signs your sensor needs calibration include consistently high or low readings that don't match ventilation conditions.

Ready to improve your indoor air quality? Browse our range of professional CO2 sensors and air quality monitors. Each unit comes with full technical support and calibration guidance. Contact our expert team today to find the perfect solution for your needs.

Frequently Asked Questions (FAQs)

What's the difference between a CO2 alarm, monitor, and detector?

Though these terms are often used interchangeably, they serve different purposes. An alarm features both detection and loud audible warnings for life-threatening situations. A monitor displays precise CO2 readings (often with an accuracy of 0.1%) for air quality assessment, featuring optional alerts. A detector simply analyses CO2 levels and connects to separate sounders in larger systems.

Why is CO2 monitoring important in offices and schools?

CO2 levels above usual cause drowsiness, headaches, and reduced concentration. Poor ventilation also creates ideal conditions for the transmission of airborne viruses. Installing CO2 monitors in classrooms and offices has become the standard method for ensuring adequate ventilation and maintaining healthy indoor environments.

Can CO2 become dangerous in everyday spaces?

Yes, but the risk varies by location. In homes and offices, elevated CO2 levels can cause discomfort and health issues, but they are typically not life-threatening. However, in confined spaces like pub cellars, breweries, and laboratories, CO2 can displace oxygen and become lethal. That's why these environments need professional-grade detection systems.

Do air quality monitors measure more than just CO2?

Many modern air quality monitors are multi-parameter devices that measure temperature, humidity, particulate matter (PM2.5 and PM10), volatile organic compounds (VOCs), and carbon dioxide (CO2) simultaneously. Some innovative models connect to mobile apps and integrate with home automation systems, allowing for automatic control of ventilation.

How do I know when CO2 levels are too high?

Many monitors use simple "traffic light" colour systems - green for good air quality, amber for caution, and red for action needed. Normal outdoor air contains approximately 400 ppm CO2. Indoor levels should remain below 1000 ppm for comfort; however, concentrations above 5000 ppm can cause noticeable health effects, such as nausea and severe drowsiness. Learn more about the differences between CO and CO2 in our detailed guide.