This article was first published onblog.nordicsemi.com
Every day, the average person inhales a staggering 11,000 liters of air, amounting to more than 300 million liters over a lifetime (as reported by TheWorldCounts).
This remarkable intake underscores the importance of ensuring the air we breathe is fresh and clean, especially since, according to the World Health Organization, there are over 6.7 million premature deaths annually due to air pollution, with more than 3.2 million of these stemming from indoor environments.
Despite the common focus on outdoor air pollution, significant health risks also originate from the air indoors. With people spending increasing amounts of time inside homes, offices, shops, gyms and restaurants it has become even more important to monitor the air quality of these environments.
Carbon monoxide alarms have been around for almost a century, while traditional smoke detectors have been around for over seventy years. But wireless technology represents a new level of air quality measurement. For example, whereas previously conventional alarms only issued warnings when dangerous levels of carbon monoxide or smoke were detected, the advent of wireless technology allows for a more nuanced and timely response to potential hazards, especially in cases of long-term, low-level exposure.
The effects of such exposure shouldn’t be taken lightly. According to an article by Julie Connolly, Senior Lecturer in Health and Social Care at Liverpool John Moores University, the symptoms of low-level carbon monoxide exposure can be difficult to spot. And yet, they have been linked to such serious symptoms as musculoskeletal injury, fatigue, and memory loss.
Beyond concerns like natural gas leaks, or carbon monoxide, carbon dioxide, and smoke build-up, humans present risks to fellow humans through viruses (such as COVID-19 or influenza). And certain strains of bacteria and mold spores also pose a threat to air quality.
One of the most serious threats, however, is from Volatile Organic Compounds (VOCs). These can lead to serious health issues, including eye, nose, and throat irritation, headaches, loss of coordination, nausea, and potential damage to the liver, kidneys, and central nervous system (according to the U.S. Environmental Protection Agency). Worse still, some VOCs have even been linked to cancer.
Now the IoT can be used to alert building occupants of these hazards, in near real-time. This allows individuals and companies to proactively implement changes to help ensure healthy indoor environments and prevent health problems.
Moreover, smart air purification and filtration systems can be integrated into smart home systems or an intelligent HVAC (Heating, Ventilation, and Air Conditioning) unit in a commercial building. A feedback loop can then be formed between the sensor network and the air purification system. When sensors detect the air quality dropping the system can automatically boost purification.
There are many advantages of employing wireless technology in these applications. Technology such as Bluetooth LE suits compact, low-power sensors working over hundreds of meters while low-power Wi-Fi technology such as Nordic’s nRF70 Series suits sensors that need a bit more bandwidth. Bluetooth LE and Wi-Fi can also work together in gateways, with the Bluetooth LE signal coming from a network of sensors, while the Wi-Fi part of the gateway sends the data to the Cloud.
Because these solutions need no wiring, they are simple to integrate into new builds or retrofit existing buildings. Compact, battery-powered sensors (such as carbon monoxide detectors) can easily be strategically installed near fossil-fuel heaters, in rooms with poor ventilation, and in other areas of concern.
Once these sensors have been set up, they continuously gather data. Edge computing enables the device to only forward information to a gateway or central device when significant to trigger further decisions such as increasing ventilation. Alternatively, the data can be sent directly to the user’s smartphone via Bluetooth LE for instant notifications. Multiple types of sensors and wireless tech enable users to build the optimum solution for the application.
For example, the AirSuite Glance, created by New Zealand company AirSuite, employs a range of sensors to monitor carbon dioxide (CO2), temperature, humidity, sound, lighting, air pressure, and volatile organic compounds (VOCs). It uses the Bluetooth LE connectivity provided by Nordic Semiconductor’s nRF52840 SoC to transmit the data directly to the user’s smartphone every minute, and the LTE-M or NB-IoT connectivity of the nRF9160 SiP to send it to the Cloud at least every fifteen minutes.
Through the dedicated app and web platform, users can oversee and receive notifications when environmental metrics surpass or fall below predetermined thresholds. Additionally, the AirSuite Monitor Web Portal offers access to historical data, allowing users to analyze trends and compare values across various rooms or sites.
There are many innovations currently shaping the landscape of indoor air quality monitoring. Notably, the development of more advanced wireless sensors—low power devices that can run for years between battery replacements—and the advancement of Machine Learning (ML)-driven analytics.
ML, with its pattern recognition capabilities, can identify trends, and intelligently adjust settings to optimize occupant health and comfort. The system can autonomously adjust settings in response to certain stimuli—such as switching on an air purifier in anticipation of the increased building occupancy expected at certain times of the day. This reduces power consumption by avoiding unnecessary equipment use and helps create indoor environments that can be continually optimized for the occupants’ wellbeing.