A retrofit project involves the modernization of an air handling unit (AHU) in a building by replacing traditional belt-driven fans with multiple EC PlugFans arranged in a fan wall configuration.

On this occasion, our partners at Rosenberg France carried out a triple project involving three AHUs at a military building. The three horizontal double-flow AHUs date back to 1998, each handling 40,000 m³/h, with installed power of 29 kW in supply air and 11 kW in return air. Two units operated continuously, while the third served as a backup system.

Although the cooling system in the IT room was generally adequate, several issues led to the fan replacement:

• High electrical consumption (approximately 60 kW in 24/7 operation)
• Extensive, recurrent and costly maintenance (belts, motors, removable scroll housings with hoist, recurring dirt accumulation)
• Lower indoor air quality.

What changes?

• Fan replacement through retrofit, upgrading to EC motors; specifically, five 500 mm diameter aluminium fans for supply air and three 560 mm fans for return air in each AHU.
• Turnkey installation: the client receives a fully installed, operational and ready-to-run solution (fans, profiles, panels, installation kit, control system, etc.).
• Anti-corrosion paint finish on sheet metal components and fans, with stainless steel screws featuring thread-lock.

Benefits achieved

• Reduced noise levels, particularly when the three AHUs operate simultaneously.
• Improved system reliability thanks to redundancy: in the unlikely event of a fan failure, the remaining units continue operating to maintain performance.
• No more belts, significantly reducing maintenance requirements and eliminating the risk of total shutdown due to belt failure.

Conclusion:

Under normal operating conditions, where only two AHUs run simultaneously, an energy consumption reduction of approximately 29% was achieved in those two units. When the three units operate in parallel, efficiency improves significantly, reaching nearly 50% energy savings.

Furthermore, it has been observed that with a simple 15% airflow adjustment, similar savings can still be achieved, demonstrating that even small operational modifications can have a significant impact on energy consumption.

The return on investment (ROI), with all three air handling units operating simultaneously, is six and a half years.

Upgrade your AHU with ECFanGrid by Airtècnics and optimize airflow, energy efficiency and electronic control without replacing the entire unit. Our team will analyze your installation and provide a tailored technical and financial proposal to maximize savings and accelerate return on investment.
Request your technical study and customized retrofit quotation today.