IoT Indoor air quality monitoring project update

28 July 2021

IoT Manager for Digital Isle of Man, Sarah Ennett, provides an update on air quality monitoring projects currently underway in the Isle of Man.

There have been more sites installed since our last update and I’m pleased to report that LoRaWAN coverage is strong in most places we have tested to date.  Below is a zoomed out view of the website visualisation MTG have provided us for the Adeunis hand held network tester, each purple dot represents a successful connection to our network and you can see that to date we have mostly carried out drive tests (and one boat test from Peel!).  The gaps show where we haven’t yet tested, so if you have an IoT project in mind and would like us to check coverage where you are, please do get in touch.

We introduced in a recent article the indoor air quality monitoring devices that we are installing.  The Milesight AM107 ambience monitoring sensor (pictured below) measures several parameters in a room; Carbon Dioxide (CO2) concentration, total volatile organic compounds (TVOC), temperature, humidity level, light levels, barometric pressure and activity levels.  These are all factors that are important to be aware of for optimal comfort, health and cognition, especially as we can spend up to 90% of our time indoors.

Carbon Dioxide or CO2 is a greenhouse gas that is natural and harmless in small quantities, but as levels rise it can adversely affect us. Most commonly produced indoors by the air we exhale, CO2 levels concentrate with low ventilation.  Up to 500ppm (parts per million) are considered to be a good level, the global outdoor air average is ~400ppm to give you a basis for comparison.  If you are somewhere without ventilation and the levels rise you will start to feel drowsy, most people notice this in the range of 700-1000ppm.  Over this level for a prolonged period of time a lot of people will experience loss of concentration and even suffer with headaches, increased heart rate and nausea.  Over 5,000ppm indicates unusual air conditions and is a probable indicator that other gases are also present, oxygen deprivation is a real concern if you spend time in that environment, whereas over 40,000ppm is immediately harmful.

I’ve been testing the monitor and doing so has already made me change my behaviour.  We now have our office windows open so the level is usually around 300-400ppm, as we are lucky to have good outdoor air quality on the Island generally speaking.  When I get back from lunch and am still breathing a little heavily from walking up the hill, you do see it spike up a little, but again it quickly comes back down thanks to the ventilation.  When I’ve taken it home to test, it’s the bedroom overnight where I’ve seen it stray above 1000ppm, two humans and a big dog all breathing out in one room, and since I’ve become aware of this as a potential issue for disturbed sleep, I’ve taken to leaving a window open there too.

Total Volatile Organic Compounds (TVOC) are a combination of gases and odours emitted from many different toxins and chemicals that can be found in everyday cleaning & hygiene products, paint and strong smelling new furniture.  Up to 250ppb (parts per billion) is considered a low level, which shows up as the first two bars being lit on the monitor screen.  If it goes above that, 3 or more bars, and stays that way for a month then you should be investigating what the source is and seeing if it can be removed as well as increasing the ventilation in that space to bring in cleaner air.  The ability of organic chemicals to cause health effects varies greatly from those that are highly toxic, to those with no known health effect.  It will depend on level of exposure and length of time, but the most commonly encountered health issues are; eye and respiratory tract irritation, headaches, dizziness and memory impairment.

Humidity is the measure of the level of moisture vapour suspended in the air, ideal relative humidity for health and comfort is between 45-55%, the air holding between 45-55% of the maximum amount of moisture it can contain. Too high humidity can cause mould growth, too low and it has been linked to the spread of viruses (when humidity levels were at 23%, up to 77% of flu virus particles were still able to cause an infection an hour after coughing).  If you know what your typical level is then aside from buying equipment like a humidifier/dehumidifier you can even do a simple thing like have bowls of water out in a dry environment which can help.  As well as the issue of increased chance of virus transmission, there are also likely to be dry eyes and skin in low humidity too.

The dictionary defines room temperature as “about 20°C”. However, what we understand as room temperature is actually a range of temperatures representing comfortable habitation for appropriately dressed humans.  This will vary between individuals but the comfortable range is usually expressed as 18-24 degrees C.  As the simplest way to improve air quality is to open windows, we need to balance that against it also typically lowering temperature.  If the people sharing the space with you are dressed warmly then this is less of an issue.

More and more studies are proving that there is a very real decline in performance on exams and an impact on decision making, if exposed to high levels of CO2.  This is why we have been working with colleagues in Tynwald and at the Department of Education, Sport and Culture to test these monitors in environments where it is important we protect the health and performance of our decision makers and our children.  Early results are really encouraging and we will be sharing more details in articles and case studies in due course.