Making Sense of Particulate Matter
Stacey Lucas explains how a technology used to protect building users during the Covid-19 pandemic is also used to monitor CO2 levels in indoor air.
The Covid-19 pandemic has focused attention on indoor air quality (IAQ) and the role of particulate monitoring as a marker of unhealthy building occupancy levels, in particular. However, despite its usefulness for detecting airbourne microbes during the pandemic, there are other important applications for the technology - and, not least, detection of a buildup of CO2 concentrations which typically record the size of each minute particle on a "PM" scale of between 2.5 and 10.
Particulate matter refers to any aggregate of solid particles or liquid droplets that remain suspended in the air for a period of time and include dust and salt particles, water and sulphuric acid droplets. These droplets can have harmful impacts on respiratory health, with particles in the PM 2.5 size range able to travel deeply into the body, reaching the lungs.
Although there are many sources, PM 2.5 pollution tends to peak in the winter months. Wood burning, coal-fuelled stoves and open fires are large contributors to emissions of particulate matter both in the UK and across Europe. A strong PM 2.5 agenda would, therefore, pay in dividends, assuring improved air quality and reducing carbon emissions in the process.
People living in highly-polluted towns and cities are realising the impact of these particles. In areas such as London, harmful amounts of air pollution (in which PM 2.5 is the most concerning) has unfortunately proven to be fatal in a minority of cases. And it isn’t just the outside environment that we should consider; we need to be mindful of the air we breathe inside. We spend around 90% of our time indoors. To assure indoor air quality, the air we breathe has to be cleansed of the particulate matter that could enter the premises from outside through open windows.
The rise of the sensor
But how do we ensure these levels are continually monitored so they don’t spiral out of control? The sector has always measured the same variables to control temperature for occupancy comfort and energy efficiency. Up until very recently there hasn’t been a demand to create air quality sensors that detect particulate matter. Instead, the focus has been on measuring CO2 levels and VOCs, both of which can have negative effects if high levels are present.
There are systems available on the market that help to treat the presence of indoor PM 2.5 levels. A potential solution would be to filter and clean the air using a HEPA filter. This filter is hugely beneficial in situations where outdoor air cannot be brought in to cleanse the indoors. These filters will also help keep air clean when employees return to offices later on this year.
Yet, the perilous concern regarding PM 2.5 levels is their invisibility. PM 2.5 is far smaller than a strand of hair, meaning that for most of us these pollutants go unnoticed. It shouldn’t be a case of ‘out of sight, out of mind’ as these particles can cause serious ill-health when people are exposed to them for long periods of time.
In order to keep an eye on these pollutants, monitoring PM 2.5 is key. Increasingly, facilities managers and building owners will need to have access to a solution which makes the invisible, visible. To keep the levels to an absolute minimum, it will be vital to utilise smart PM 2.5 sensors. The sensors will have their sights on something we humans cannot see and will greatly help assure indoor occupant comfort when it is most needed. Installing a smart sensor on the wall – as part of a high-performance BMS system – is a crucial manoeuvre in the clamp down of particulate matter.
This demand for more sensors in general is being propelled in the United Kingcom by the Mayor of London's "Breathe London strategy", which was launched in January 2019 and aims to provide the city's residents with up-to-date air pollution information, provided by sensor technology. But we have also seen the EU introduce some new legislation on particulate matter and the levels deemed harmful. Clearly sensor technology is in high demand, and over the past year the likes of Sontay have seen architects and consultants specifying more and more of them especially PM 2.5.
The PM 2.5 sensor is a new solution on the market, and many systems integrators are approaching sensor manufacturers for support and advice on what they need to do. Like other manufacturers, Sontay have launched a PM 2.5 sensor informec by an awareness that approaches to tackling particulate matter must be holistic as it is as important for building controls to be in place to monitor levels as it is for users to be educated on what PM 2.5 is, its dangers, and the measures they can adopt to assure indoor comfort is not jeopardised. In that sense, it will take a sizeable shift in perspective to really understand and grapple with the effects of PM 2.5 and what can be done to control it.
Sensor technology in general has been heralded by key government individuals and bodies as one of the ways to reduce problematic levels of air pollution. Sensors have the ability to monitor the invisible, ensuring our indoor environments are in the best condition for occupants as possible. It will now take some time for industries to educate people on the negative impacts of particulate matter, keeping them mindful of what they need to do to keep their health continually in check. Thankfully, the introduction of particulate matter sensors to the market will no doubt be an assurance to many, enabling us all to breathe easy when at work or play.