The renovation of an Air Handling Unit (AHU) in tertiary sector buildings cannot be viewed as an expense, but rather as a strategic investment with measurable returns. In a context where energy efficiency marks the difference between a competitive installation and an obsolete one, updating the key components of a dual-flow AHU can result in energy savings exceeding 40% and virtually eliminate unplanned shutdowns.
In this article, we explain what a comprehensive AHU renovation entails, what technologies make it possible, and why system redundancy is the differentiating factor most valued today by installers and facility managers.
A dual-flow Air Handling Unit (AHU) is the centerpiece of the ventilation system in tertiary use buildings: offices, shopping centers, hotels, hospitals, or highly demanding industrial facilities.
Its function is to simultaneously control the supply flow of fresh air and the extraction of stale air, recovering energy in the process through a heat exchanger.
Over time, the supply and return components age: belt-driven fans lose efficiency, bearings require maintenance, and any failure can shut down the entire installation.

In a reference tertiary installation, our partners at Rosenberg France have carried out a complete renovation of the supply and return modules of a dual-flow AHU, replacing conventional technology with an ECFanGrid.
The system self-regulates in case of fan failure, ensuring service continuity.
| Feature | Conventional AHU | Fan Wall AHU |
|---|---|---|
| Energy efficiency | Medium (IE1-IE3) | High (IE5) |
| Redundancy | No | Yes |
| Maintenance | High | Low |
| Shutdowns | Frequent | Almost non-existent |
| Air distribution | Non-uniform | Uniform |
Do you have an AHU that needs renovation? Contact our specialists and receive a personalized proposal.