We all know the feeling of being stuck in a crowded room: feeling increasingly tired and finding it difficult to concentrate, but research is increasingly able to quantify the link between concentrations of CO2 and productivity, and it’s an analysis that presents some interesting questions for the future.
For most people, a CO2 concentration of 1000 parts per million (ppm) is the threshold at which a room starts feeling stuffy. CO2 levels in indoor spaces routinely exceed this, and it has a measurable impact on productivity.
A recent Harvard study, conducted across six countries, has found that poor indoor air quality negatively impacts cognitive function. Office workers were given colour-based and arithmetic-based tests and, where CO2 levels were higher, workers’ response times and accuracy was significantly slowed.
The British Council for Offices has shown through one study that employees’ test scores improve as CO2 concentrations fall. In one of the buildings included in the study, people worked 60% faster in reduced CO2 environments, completing tests in a mean time of 8.2 minutes, compared with 13.3 minutes in rooms with higher than average CO2 in the atmosphere.
Another study by the World Green Building Council found that increasing ventilation and lowering levels of CO2 in the workplace from 1000ppm to 500-600ppm delivered an 8-11% improvement in productivity.
In the decades to come, the climate crisis could increasingly be accompanied by a productivity crisis in our indoor spaces. Atmospheric CO2 levels rose from a pre-industrial level of 280ppm to pass 400ppm in 2015 and are projected to exceed 900ppm by the end of this century. That level is uncomfortably close to our “stuffy room” scenario, particularly as indoor concentrations of CO2 tend to be higher than those outdoors.
If atmospheric CO2 rises as projected, this will increase the potential for our built environment to have a deleterious impact on productivity for all of us. Academics from the UCL Energy Institute have found that by the end of the century, based on a business-as-usual projection of global CO2 emissions, it will become impossible to stay within current guidelines on indoor CO2 concentration without resorting to expensive and energy intensive approaches, such as CO2 removal.
A major challenge is coming, and we need to begin to prepare now by changing our approach to the design and servicing of office buildings. New office buildings are built to be airtight, and the quality of the indoor air is heavily reliant on ventilation and air conditioning, but where air is reused and circulated internally this can inadvertently result in poor air quality. It is important that building owners begin take steps to understand and measure this, then feed the information back to occupiers, allowing them to make decisions to protect the wellness of their employees.
Real-time monitoring of indoor CO2 within existing buildings is a logical first step and easy to implement – an affordable and simple sensor can alert occupants of a meeting room that the CO2 concentration has exceeded a comfortable limit and guide them to ventilate or vacate the space, for example.
In the longer term, the paradigm of office design needs to adapt to allow natural ventilation, which combined with intelligent monitoring and feedback, is the low energy solution to reducing concentrations of CO2 to create a healthier indoor environment.
If atmospheric CO2 levels continue to rise, the margin of error for buildings to exacerbate air quality issues while remaining usable will be squeezed. Keeping concentrations of CO2 down to a level that is acceptable by current standards is going to become much more costly, difficult, and environmentally problematic, unless we plan for the worst, make intelligent use of the buildings we already have by retrofitting them with sensors, and begin to build differently.
Francesca Brady is a Forbes 30 Under 30 Entrepreneur and co-founder of AirRated.
Francesca holds a Masters degree in Environmental Geoscience from Royal Holloway, University of London. During her Masters research, Francesca became passionate about the topic of indoor air quality (IAQ). As Head of Environmental Research at AirRated, she contributed to the development of the AirScore – a tangible and quantifiable building certification which aims to set the global benchmark for indoor air quality by communicating the health of indoor environments. Francesca became CEO of AirRated in 2020.