An introduction to the indoor air quality monitoring guide and why indoor air quality is important.

The Covid-19 pandemic has increased awareness of the immediate need to improve indoor air quality inside buildings. Doing so effectively, without compromising the comfort of occupants, demands dedicated monitoring of carbon dioxide, temperature and humidity in the indoor environment.

Indoor air quality and public health

The state of indoor air quality in the UK - and its effects on our health - has come under new scrutiny due to the airborne spread of coronavirus in poorly ventilated indoor spaces.

However, many institutions, including the Chartered Institution of Building Services Engineers (CIBSE, UK), the Scientific Pandemic Insights Group on Behaviours (SPI-B, UK) and the Building Engineering Services Association (BESA, UK), are anxious that management of indoor air quality should continue beyond the pandemic. This is due to the significant impact of indoor air quality on our overall health.

Poor indoor air quality, aside from encouraging the spread of contagious diseases, has been linked to respiratory illnesses (such as asthma and cancers), Alzheimer's disease, heart disease and inflammatory conditions. Considering that people in the UK spend up to 90% of their time indoors, it is undeniable that indoor air quality is affecting our health.

Monitoring the indoor environment effectively provides the first step to improving indoor air quality and promoting long-term public health.

Where to begin with monitoring indoor air quality: CO₂

Indoor air pollutants include particulate matter, carbon monoxide, carbon dioxide, radon, volatile organic compounds (VOCs), mould and humidity.

Monitoring for many of these pollutants can be costly and impractical; however, cost-effective and accessible monitoring options are available for measuring CO₂.

Carbon dioxide, while naturally present in the air, also builds up in occupied spaces due to occupant respiration. If levels of CO₂ are consistently high in an occupied space, it suggests that there is an inadequate supply of fresh air and that indoor air quality is poor. An understanding of CO₂ levels in an indoor space can therefore inform strategies to improve air quality (e.g. increasing ventilation rates).

Methods for improving air quality, however, such as ventilating through natural or mechanical means, can adversely affect indoor temperature and humidity levels, both of which are important for indoor comfort. Unexpectedly low levels of temperature and humidity can also reveal instances of energy loss resulting from increased ventilation rates. Any attempts to improve indoor air quality must therefore consider and balance the implications for occupant comfort and energy costs.

Monitoring CO₂, followed by temperature and humidity, is a simple, cost-effective way to begin building an adaptable indoor air quality strategy that also prioritises and improves occupant comfort and saves energy.

Next page: CO₂ Data Loggers: Visualising Air Quality

Go back to: How to Monitor Air Quality Effectively

References and further reading