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Everyone needs healthy air whether at home or at work. Poor air quality can lead to chronic illnesses, reduced cognitive abilities, fatigue, lack of focus, and dizziness. It also can contribute to increased infection rates of viruses, such as COVID-19, influenza, and the common cold.

Monitoring indoor air quality (IAQ) calls for sensors that can measure carbon dioxide (CO₂) and Volatile Organic Compounds (VOC). Sure, that's a lot of acronyms, but it's important to remember that CO₂ and VOC sensors are not interchangeable. They measure different things.

CO₂ sensors keep us healthy and comfortable. They are the most widely used measure for IAQ and are designed to control the ventilation rate in occupied spaces. Because people are the main source of CO₂ in indoor air, CO₂ sensors measure the rate of air exchange required for a healthy level.

VOC sensors know when something assaults our sense of smell. These sensors optimize proper ventilation to ensure the highest air quality for occupants and reduce utility costs for building owners. VOC sensors can be used to detect high pollution that might occur when special equipment is being used or when potent chemicals from cleaners are released into the air.

CO₂ sensors would specifically reduce ventilation during unoccupied periods, but VOC sensors might maintain ventilation rates during unoccupied periods if a significant pollutant level in the building is detected.

Now that we know the difference, this week's New Tech Tuesdays highlights two Sensirion digital microsensors available for solution-based development.

Sensirion SCD30 Sensor Module has a lot going for it. It's the first solution offered by Sensirion specifically developed and designed for HVAC systems. The SCD30 sensors, based on CMOSens^® Technology, provide all the environmental data to make the heating, ventilation, and air conditioning (HVAC) systems smarter. Sensors can also be integrated into air purifiers and intelligent thermostats, and other smart home products. SCD30 also features dual-channel detection for superior stability and ±30ppm + 3 percent accuracy. SCD30 uses non-dispersive infrared (NDIR) sensor technology to detect CO₂ and has an integrated humidity and temperature sensor. Over the years, CO₂ sensors have gained increasing significance in monitoring air quality.

Sensirion SGP40 Indoor Air Quality Sensor is a VOC sensor ideal for applications such as air quality monitoring and automated air quality control systems, such as air purifiers, kitchen hoods, and demand-controlled ventilation systems. SGP40 is a complete sensor system on a single chip and features a digital I²C interface, a temperature-controlled micro-hotplate, and a humidity-compensated indoor air quality signal. The sensor also uses the manufacturer's VOC Algorithm to analyze VOC events and map them to a VOC Index. This index provides a practical quantification of VOC events relative to each sensor's average indoor environment. In this way, the sensor behaves like the human nose, which is sensitive to odor changes, but it also senses VOC events not perceived by humans.

These Sensirion CO₂ and VOC sensors do the heavy lifting when it comes to detecting air quality. They have different functions, but their common purpose is to keep our air healthy and comfortable and save energy.