What are the optimal air quality levels for health, productivity and energy-saving?
September 26, 2022
Indoor air quality has an enormous effect on people's well-being and productivity. For example, did you know that a healthier work environment can reduce sick leave by 58%?1 On top of that, buildings are responsible for 40% of global energy consumption and 33% of greenhouse gas emissions.2
Most researchers agree that in places like offices, carbon dioxide levels that are below 800 ppm are considered ideal.3 If indoor concentrations begin to exceed 1000 ppm, people’s decision-making performance is likely to worsen4 by at least 50%.5
Decision-making is an essential part of business. With high levels of CO2 in the workplace, workers are slower to respond to daily challenges, which greatly reduces productivity. It also means virus transmission is more likely due to a lack of fresh oxygen.
Like radon, there are no ‘optimal’ levels for particulate matter. However, in 2021 the World Health Organization did update its guidelines on this pollutant.6 Now, the recommended limit for PM2.5 is 5 µg/m3 in terms of annual average concentrations. Average 24-hour exposure should not exceed 15 µg/m3 for more than three to four days a year.
Why does it matter?
Particulate matter is especially harmful to occupants with breathing difficulties, such as asthma. Monitoring PM levels and taking action when necessary will help businesses actively demonstrate that they care about this issue, boosting staff morale in the process.
Even though personal preferences do vary, a 2014 study concluded that indoor workers make fewer mistakes when the temperature is set to 71.6°F.7
However, keep in mind that the exact ideal temperature will depend on your location and the season—in fact, one study has shown that by reducing classroom temperatures in late summer from 77°F to 68°F (25 °C to 20 °C), the performance of students significantly improved.8
As long as you don’t deviate too far from 71.6°F, you can ensure thermal comfort for your occupants.
The temperature of a building has a clear effect on how comfortable occupants feel when performing tasks, which has a knock-on effect on their ability to concentrate and collaborate with one another.9 What’s more, sticking to a moderate temperature will help businesses save on energy bills.
Indoor environments with a humidity level of below 30%-40% make the spread of infections more likely.10 However, if the level exceeds 70%, mold and other fungi are likely to grow.11
The higher transmission rate of infections means that occupants have to take sick leave days more often. Mold, on the other hand, damages your building’s structure and can make your facilities uninhabitable. Both issues can severely disrupt business operations.
Airborne chemicals (VOCs) consist of many substances of varying toxicity. However, there should be less than 250 ppb of any one chemical in an average indoor environment.12
Airborne chemicals can cause eyes, nose, and throat irritation. This can cause occupants to become less satisfied with their building, which can decrease its property value. They even made a name for this phenomenon–sick building syndrome.13
Having a low virus indicator reading helps you put occupants at ease. This is especially important in light of the pandemic, as people are more likely to be anxious about public spaces.
With radon, there is no set ‘optimal’ level (the lower the measurement, the lower the risk). Still, the World Health Organization states that levels below 100 Bq/m3 or 2.7 pCi/L are not a cause for concern.14
Ensuring that your building does not trap excess radon is key to ensuring safety for all occupants and visitors. In some countries, doing so will even help you stay compliant with government regulations.15
There is no specific ideal air pressure level for buildings. In some industrial and laboratory settings, air pressure may help technicians operate machinery more accurately, but the ideal measurement will depend on the context.
In U.S. hospital settings, rooms that contain patients with infectious diseases must have a negative pressure differential of at least 2.5 Pa.16
Hospitals are legally required to keep some rooms under negative pressure, so contaminated air does not leak into uncontaminated areas.
According to the US Department of Labor’s OSHA Workplace Lighting Guidelines, lighting in office spaces should typically be 500 lux.17 This is also the recommendation in the United Kingdom for paper-based tasks.18 In other countries or fields of work, recommendations may vary.
All commercial buildings should be sufficiently lighted. Not doing so can cause eye strain, fatigue, and headaches. All of these conditions negatively impact health and well-being.
According to the World Health Organization, clear speech perception is only possible if background noises do not exceed 35 dB(A).19
Background noise can be extremely distracting to building occupants. It also hinders communication and collaboration between employees.