As we move deeper into autumn and, with the knowledge that for very many people, working from home will be commonplace for the foreseeable future, the issue of air quality becomes more important.
‘Good’ indoor air quality is very hard to define, and very subjective. There are some pollutants that must be considered as potentially damaging to health, such as fine particulates (PM10, PM2.5), various oxides of Nitrogen (often written as NOx), a cocktail of volatile organic compounds (VOCs) and ozone. These are often generated outside of the home, especially as combustion products or from vehicle emissions, although some are also produced by domestic activities, such as cooking and cleaning.
Local air quality is affected by a whole host of factors, such as proximity to roads or industry, and also the weather. In the autumn and winter we experience storing winds, which are good for dispersing and diluting pollution, but also very still days when pollutants can be trapped in the lower atmosphere where they build up to risky levels. This air also finds its way inside our homes – more so than in offices, which are often quite air tight and fitted with sophisticated air management systems (usually referred to as HVAC systems: heating, ventilation and air conditioning)
Something else to consider is the amount of pollution created in the home, especially in the kitchen. Cooking produces a whole host of volatile organic compounds. Particulates and combustion products are also produced – especially if you are prone to burning food.
Now, of course, we have an additional factor to consider. Airborne infections spread on aerosols (the fine droplets created when coughing or sneezing), whether as a result of Covid-19, or the common cold, will have to be factored into the way that homes are heated and ventilated.
Health advice recommends high levels of ventilation to reduce the risk from aerosol infections, but in a house, that means opening doors and windows (rather than adjusting a complex HVAC system), and that might mean letting expensively heated air out and polluted cold air in.
On the other hand, it also means letting cooking fumes and carbon dioxide out, so it might be possible to maintain a healthy balance. But how would you know?
Air quality data
There is an old saw that says that you can’t manage what you can’t measure. With air quality, that is especially true. Pollution is pretty-much undetectable by the senses (you might smell fumes, but you couldn’t possibly estimate the concentration), so the only way to know for sure is to have access to data.
Local outdoor air quality data can be found on various web sites, and these are pretty accurate within a few miles (but generally not down to street level). A good example is https://www.iqair.com
This screenshot shows the air quality around my location (marked by a red dot), with my closest monitoring station shown in the box. However, local knowledge tells me that the air quality in Belvedere – an urban area – is likely to be a little different from my semi-rural location (although on the occasion of this reading, the whole area looks to have very similar air, and pretty good, air quality.)
Indoor air quality is a different matter, however, and the only way to know what is in the air inside your house is to measure it.
There are very many indoor air quality (IAQ) monitors on the market for domestic use. Some resemble toys and others look a bit like medical devices. Others are a little more subtle.
With IAQ monitors, the quality of the data depends very much on the quality of the sensors, and that can vary. There is some truth that you get what you pay for and if you can afford it, spending a little more will get you a better monitor.
Some IAQ monitors connect via WiFi and will send data to an app on your phone, and some can even be connected to smart home devices, so if a certain threshold is breached, it can switch on a fan, or an air purifier or dehumidifier, for example.
This is an example of a domestic IAQ monitor (the Awair Element) that displays IAQ data on the front of the monitor and on an app.
What should be measured
As a minimum, a domestic IAQ monitor should be able to measure total VOCs, fine particulates, temperature and humidity. Carbon dioxide measurement is also useful. The monitors should also be able to display an overall air quality score as well as the individual parameters, and that can help the user to decide what to do (e.g. open or close a window).
VOCs and fine particulates (PM2.5) can be quite dangerous. Carbon dioxide less so, unless at extreme concentrations. However, carbon dioxide is worth keeping an eye on, as at concentrations well below harmful levels, it can make you feel drowsy, have an effect on the ability to concentrate and can impair cognitive functions. The source of carbon dioxide is mainly people, and it doesn’t take long for levels to increase in a well sealed building with a few people in it.
Using data to help you make decisions
There may be times when you see the various IAQ parameters on your monitor telling you different things about the overall IAQ. For example, you may notice that particulates and VOCs are quite low, but carbon dioxide is increasing. Opening a window will certainly reduce the concentrations of carbon dioxide, but may result in the other pollutants increasing as outside air is let in. However, unless outdoor air quality is really bad, it is unlikely that in the short time a window is opened to flush out the carbon dioxide that concentrations of the other pollutants will rise to concerning levels.
Knowing about IAQ will help you make informed decisions about how to manage your indoor environment, such as heating, ventilation, use of plants or avoidance of certain chemicals or activities – will you work in the kitchen while someone else is frying bacon or burning toast, for example?
Without the data, you wouldn’t know.
IAQ monitoring as part of the home-workers office kit
If you are used to working in an office, there is a good chance that IAQ is already monitored – it will be used to help manage HVAC systems. If your office has a wellbeing certification, such as WELL or RESET, you should find that IAQ data is shared with all the users of the building.
Knowing about IAQ in an office can be empowering and be useful to help building managers understand local issues (i.e. your immediate surroundings), as well as what is going on in the whole building.
As a home worker, this information is also very useful, as it will help you manage your working environment and keep it as healthy as possible.
Working with my colleagues at Fusion Spaces, we are developing the WorkFreeTM home workspace assessment method to look further into managing home office space to be as healthy, safe, comfortable and empowering as it can be.