Why CO2 sensors alone are not enough

When people share a room, the amount of exhaled carbon dioxide (CO2) usually increases sharply. But performance is not solely dependent on the CO2 content; other factors also play a role.

What are CO2 sensors?

Well-being, performance, and motivation are closely related to the CO2 concentration in the room air. CO2 is a tasteless and odorless gas that humans cannot perceive. However, its effects are very much noticeable, with poor concentration, reduced performance, and discomfort rising in direct relation to an increasing CO2 concentration in the air. To illustrate:

  • Percentage of oxygen inhaled air: 21% vol
  • Percentage of CO2 inhaled air: 0.035% vol
  • Proportion of oxygen in exhaled air: 16% Vol
  • Proportion of CO2 in exhaled air: 4% Vol
  • Toxic concentration of CO2: from 2.5% vol
  • Decrease in performance: from 0.1% vol. CO2

CO2 sensors monitor the concentration of carbon dioxide in rooms depending on other parameters (number of people in the room, number of open windows, room temperature, air pressure, etc.). If defined limit values are exceeded, CO2 sensors trigger a warning signal.

Whereas in the industrial sector CO2 sensors are common and legally required in companies where gas is used, since increasing CO2 concentrations in the air are associated with dangers to life and limb, the innovative technology in the public sector only came into focus in the course of the current pandemic. However, the positive effects of CO2 sensors are undisputed, regardless of the prevention of high concentrations of pathogens.

How are CO2 sensors used effectively?

The performance of employees in companies, as well as the concentration of students, conference participants, and others who gather in enclosed spaces, is closely related to air quality. Poor air quality results in unproductive working conditions.

CO2 sensors measure the level of carbon dioxide in the air and provide usable feedback: When does ventilation need to be implemented? Should employees take a break?


CO2 sensors can only be used effectively if they can be optimally adapted to the existing spatial conditions. Like AIRICA 's indoor air quality sensors, they must therefore be scalable and take into account the size of the room and the number of people in it. Companies also demand the greatest possible cost efficiency and integration into the existing infrastructure.

All these requirements are met by AIRICA, which also enables monitoring of humidity and air pressure as well as room temperature. Furthermore, VOC – volatile organic compounds – are taken into account in the measurements to provide an overall picture of the air quality.

This is the only way to achieve real efficiency in the use of the sensors. Thanks to clear and intuitive dashboards, users can obtain an overview of the current situation and the development of indoor air quality at any time. Optimizations of ventilation management can be derived from this.

In a nutshell: CO2 sensors can always be used effectively if they meet these conditions:

  • Simple, intuitive use, and accurate measurement
  • Consideration of other measured values
  • Fast and cost-effective installation (long battery life)
  • Integration into existing systems
  • Derivation possibilities for further courses of action


Advantages of CO2 sensors

The advantages of CO2 sensors must be considered in a differentiated manner for all parties involved:

Human Resources Division

The use of CO2 sensors improves air quality and makes employees feel more comfortable. A lower proportion of CO2 in the air increases performance and receptiveness, fatigue, and loss of concentration are reduced. An improved sense of well-being and more motivation contribute to physical and mental health.

Employees are less likely to fall ill and are more productive and resilient. The indoor climate contributes to the well-being of employees


At the same time, they perceive the employer as modern, responsible, and secure, and employee loyalty to the company increases. This also increases productivity.

Facility Management

The management of a building should be efficient and plannable, thus increasing safety and cost savings. This goal can be achieved through effective data analyses and the derivation of recommendations for action from the data.

Corporate management area

High-performing and motivated employees who value their employer contribute to the success of the company. Reduced absence due to sickness means that production can be better planned and, at best, increased. The productivity, effectiveness, and performance of the employees is high

Last but not least, especially in view of the annually recurring waves of illness caused by, for example, the flu, employees feel safer if the indoor air quality is positively influenced. Due to a low CO2 concentration, the air pollution with aerosols and germs is also low and the risk of infection decreases rapidly.

That is why further measurement data are necessary

The CO2 concentration in rooms where only one or two people are present is naturally much lower than in rooms of the same size that are used by 10 or more people at the same time.

The level of CO2 content in the room air depends on biotic and abiotic factors. These include the occupancy and size of the room, the duration of use, and the number of people.

The activity of the people in the room, the ventilation, and the presence of other influencing factors (candle and tobacco smoke, operation of technical equipment, fermentation processes) must also be taken into account.

This means that the measured CO2 value must not be the only decisive factor in assessing the quality of the room air. Other measurement data must also be taken into account because a high concentration of VOCs can dangerously alter the air we breathe.

Surely you are also familiar with newly manufactured furniture that smells toxic because of the escaping formaldehyde, the fine dust of candle soot that triggers coughing, and the chemical smell of cleaning agents. Indoor air with a low CO2 content and a high oxygen concentration is not automatically healthy per se. These substances and compounds also accumulate in the air and have an unfavorable effect on the well-being and health of the people in a room.

In order to enable your employees to work in a healthy manner, it is therefore necessary to consistently collect further measurement data with which the indoor air can be assessed. In addition, many effects of poor indoor air quality can be avoided by proper ventilation (forced ventilation: open all windows several times a day for a few minutes or provide a brief draught)


Conclusion: CO2 sensors are only one part of the indoor air concept

From the above considerations, it can be concluded that CO2 sensors play a significant role in the assessment of indoor air quality. They help to keep the amount of CO2 in the air as low as possible, because a timely alarm indicates the need for ventilation.

Employees work more concentrated and efficiently thanks to a better supply of oxygen. The effects of CO2 sensors in the company are therefore beneficial for employees and for the company itself, as performance increases. Nevertheless, they must always be combined with other measurement data in order to actually assess the room air in a resilient manner.