Carbon dioxide (CO₂) is a non-flammable, colourless, and odourless gas that occurs naturally in the Earth’s atmosphere. It is also produced by human respiration, which means its concentration can rise quickly in indoor spaces with more occupants. In addition, CO₂ is released during the combustion of fossil fuels.
Outdoor CO₂ levels are typically around 400 ppm (parts per million), while in urban environments they can range between 600 and 900 ppm.
Optimal CO2 Level?
According to commonly used European guidelines, indoor air quality is generally considered good when CO₂ levels remain below 800 ppm. Levels between 800 and 1400 ppm indicate moderate air quality, while concentrations above 1400 ppm suggest insufficient ventilation and poorer indoor air quality.
In practice, many recent standards recommend keeping CO₂ levels as close as possible to outdoor conditions (typically around 400–500 ppm), with values below 1000 ppm often used as a general target for well-ventilated spaces.
How Does CO2 Affect You?
There are correlations that CO2 above 1500 ppm reduces concentration and causes headaches and drowsiness, while concentrations below that are associated with increased productivity, enhanced cognitive abilities, and better performance.
At extremely high levels, CO2 can lead to suffocation and oxygen deprivation, resulting in fainting, and potentially even death. However, this occurs at CO2 levels above 100.000 ppm, which, under normal circumstances, is not possible.
How to Improve CO2?
You can reduce CO₂ concentration indoors by ensuring an adequate supply of fresh air. This can be achieved by using a central ventilation system or by opening windows. To make better decisions about when and how to ventilate, it is helpful to monitor indoor air quality. Using an indoor air quality sensor that also provides information about outdoor conditions allows you to balance fresh air intake with external pollution levels. Sensees Indoor sensors offer this combined insight, helping you optimise indoor air quality more effectively.
If you live near busy roads, it is advisable to avoid opening windows during peak traffic hours. Introducing fresh air will quickly lower CO₂ levels in a room, depending on its volume. Without sufficient ventilation, the concentration of pollutants can rise to levels that may impact comfort and well-being.
CO₂ levels can also be managed by controlling their sources. For example, avoid smoking indoors and use a hood while cooking. Adding plants can have a small positive effect, although ventilation remains the most effective solution.