Correct ventilation in the office

This is how you create an optimal room and work climate

Office workers spend many hours a day at work. There is often a loud discussion here with colleagues, talking on the phone or simply working in silence. The concentration of CO2 increases quickly in the interior. But aerosols, micro particles loaded with viruses, also accumulate in the room air. Regular ventilation therefore not only promotes concentration and prevents headaches. Air exchange is essential when it comes to avoiding infection with infectious diseases.

Disadvantage of preventive (full) ventilation in the office: The room air cools down quickly, especially in winter, we freeze and have to re-heat at an expensive rate. And once our feet are cold, we are more susceptible to supposedly harmless cold viruses.

Mechanical ventilation can help here. With decentralized ventilation devices with heat recovery, a continuous air exchange can be established, which reduces the intermittent ventilation intervals in the case of aerosol or CO2 peaks to a minimum. Big advantage: Installed in the outer walls, retrofitting is quick and easy.


Workplace directive for indoor air hygiene

Office rooms must be designed in such a way that: “There is sufficient health-friendly breathing air available” (ASR A3.6, p.3). Requirements for free ventilation via windows and ventilation via mechanical ventilation systems are set out in the workplace guidelines ASR A3.6 and A3.7.


CO2 concentration as a benchmark for indoor air quality

The CO2 concentration is a recognized measure for assessing indoor air quality. According to the workplace directive, this should not exceed 1,000 ppm. This can be achieved by opening the windows, mechanical ventilation, or a combination of both.



  • Discharge used room air
  • Minimize the risk of infection


  • Simple retrofitting in the outer wall
  • Set the ventilation intensity intuitively
  • Heat recovery through ceramic core
  • Fresh air at a comfortable temperature



Minimize infection risk through ventilation in the office

In addition to the removal of CO2, the mechanical ventilation also prevents infections. Existing aerosols are transported to the outside via the devices, the fresh air supplied lowers the concentration of the aerosols in the room air.

The combination of mechanical ventilation with heat recovery and window ventilation is an effective way of bringing healthy fresh air into the office without high heat loss.

The use of efficient ventilation systems can completely replace ventilation via the windows or, as ventilation support, reduce window ventilation to a minimum.


The following example shows the ventilation with the iV-Office for these two options.

Planning Example Office Ventilation

3 alternatives on how to keep the CO2 limit in the office with ventilation

  1. Full window ventilation via windows: 3 - 10 min/h
  2. Ventilation with air conditioning system: approx. 30 m³/h per person
  3. Combination of full window ventilation and mechanical ventilation


Planning example for ventilation in offices ...

  • Ventilation for the office



    • 30 m³/h per person
    • Required outside air volume flow for 2 people through the ventilation system = 60 m³/h

    In this case, the iV-Office is designed with 30 m³/h per device, resulting in an outside air volume flow of 60 m³/h with 2 devices in the room (one device pair).




    The workplace directive is met. No further action is necessary.

  • Requirement:


    • 30 m³/h per person
    • Required outside air volume flow for 4 people through the ventilation system = 120 m³/h

    In this case, the iV-Office is designed with 30 m³/h per device, resulting in an outside air volume flow of 60 m³/h with 2 devices in the room (one device pair). This design corresponds to a volume flow of 15 m³/h per person.




    The requirement of the workplace guideline of 30m³/h per person is not fully met in a 4-person office. Continuous basic ventilation, however, is achieved within the specified sound emission requirement (here: 40 dB(A)).

Halve the boost ventilation intervals

In the example of the 4-person office, the air exchange can be temporarily increased to up to 90 m³/h before and after use.


In this case, the missing outside air volume flow can be reached through the windows. By fulfilling the requirements to 50%, the required number of boost ventilation can be halved. In the example of the 4-person office, this means: full ventilation every 2 hours.


Your advantages:


  • Infection prevention through the removal of aerosols
  • Low virus concentration due to high proportion of fresh air
  • Reduction of window opening cycles


Do you have questions about ventilation in the office?

Write us a message. Our ventilation experts will be happy to help you.

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