Updated on 20.8.2026
The greatest energy savings in ventilation is often gained with demand-controlled operation.
The energy consumed by ventilation falls down to less than half when the power of ventilation is reduced by the same amount. When the rooms are empty, the need for ventilation decreases significantly and it is sensible to decrease ventilation.
Changing working environment – changing needs
The length of a working day used to be standard. Everybody was at work from eight to four and the need was at its greatest then. Nowadays, however, the rooms are more varied and work is more mobile. Offices may be empty for long periods of time as the employees work remotely, visit their customers or sit at meetings. The quality of air in a meeting room full of people can be lousy, whereas ventilation is at full power in the offices, consuming energy unnecessarily.
Decentralised ventilation and carbon dioxide sensors create automatic room-specific ventilation. The sensors measure the quality of indoor air and boost ventilation when needed. This ensures that air in the meeting room stays fresh and the participants stay awake, while ventilation in the empty rooms decreases, keeping energy consumption in control.
Occupancy-Based Ventilation in Workplaces
The ventilation requirements of commercial buildings vary continuously according to how the spaces are used. Vallox Pureo air handling units provide a flexible solution by enabling ventilation to be controlled based on actual demand, in other words according to occupancy levels. Vallox Pureo air handling units are designed for a wide range of commercial applications, including offices, retail premises, industrial and warehouse buildings, as well as public facilities such as schools and daycare centres. In these types of buildings, ventilation requirements can vary significantly depending on occupancy, highlighting the importance of demand-based control.
Occupancy-Based Control with Pureo Air Handling Units in Commercial Buildings
A key strength of Pureo air handling units is their versatile control capabilities. The units can be equipped with advanced control systems and integrated with the building automation system.
Ventilation control can be implemented using:
- Weekly schedules based on building occupancy hours
- Presence detectors
- Sensors such as CO₂, humidity, and VOC sensors
These enable the ventilation system to automatically adapt to occupancy levels and indoor air quality conditions. For example, a humidity sensor connected to a Pureo unit can detect increasing moisture loads in the indoor air and automatically boost ventilation when needed. Read more about this in the reference project of a fire station, where indoor air quality and ventilation performance were improved with a Vallox Pureo TX air handling unit.
An Energy-Efficient and Easily Adaptable Pureo System
Pureo air handling units can be delivered either as terminal block units without controls or with a complete control system including electrical and control equipment. Automation can also be expanded later by adding sensors, making it possible to upgrade the system to demand-controlled, occupancy-based ventilation as requirements evolve. In addition, the units are compatible with various building automation systems, enabling ventilation to be integrated into broader building management solutions.
The energy efficiency of Vallox Pureo air handling units is enhanced by highly efficient heat recovery, which improves the overall energy performance of the ventilation system.
When ventilation adapts to occupancy levels, unnecessary ventilation is reduced, energy consumption decreases, and indoor environmental conditions remain well controlled. Demand-controlled operation complements the benefits of heat recovery by ensuring that the right amount of ventilation is provided at the right time. As a result, ventilation can be delivered efficiently, energy-efficiently, and in line with the actual usage of a wide range of commercial buildings.