Many commercial buildings operate their Fresh Air Handling Units (FAHUs) almost continuously—even when ventilation demand changes throughout the day.The result? Higher energy consumption, unnecessary equipment wear, and rising operating costs.The question isn't whether your FAHUs are running. It's whether they're running intelligently.

The Challenge Wasn't the Fans Alone

At Swiss Tower in Dubai, four FAHUs supplied fresh air throughout the building.The existing belt-driven AC fans were reliable but inefficient. Operating at a fixed speed, they continuously consumed 28–31 kW, regardless of actual occupancy or ventilation demand. Over time, energy waste and maintenance costs became increasingly difficult to ignore.

Pic.1 Fresh Air Handling Units (FAHU)（Source from：Qey Energy Solutions）

A Smarter Retrofit Strategy

Instead of replacing the entire FAHU system, the project upgraded the units with ebm-papst RadiPac EC centrifugal fans and introduced a demand-based control strategy.

Connected to the Building Management System (BMS), the EC fans automatically adjusted speed according to real operating conditions—delivering only the airflow the building actually required.

Pic.2 Technical data of fans（Source from：Qey Energy Solutions）

The Results

The retrofit reduced peak fan power from 31 kW to 16.5 kW, achieving more than 60% energy savings.

Additional benefits included:

• Lower maintenance with direct-drive EC technology

• Improved reliability and quieter operation

• Intelligent BMS communication and monitoring

• Extended service life of the existing FAHUs

Pic.3 The renovated fan grids（Source from：Qey Energy Solutions）

The Bigger Lesson

This project highlights a growing trend in commercial HVAC retrofit.

The greatest efficiency gains don't come from replacing entire systems—they come from combining high-efficiency EC fans with intelligent airflow control.

For many commercial buildings, optimizing existing infrastructure delivers a faster return than complete equipment replacement.

Beijing Hengrui's Perspective

At Beijing Hengrui, we help customers improve HVAC performance through application-focused fan selection, AHU/FAHU retrofit solutions, and airflow optimization. Our goal is not simply to replace fans, but to build smarter, more energy-efficient ventilation systems.

Is your ventilation system delivering the airflow your building needs today—or the airflow it was designed for years ago? We'd love to hear how you're approaching HVAC retrofit and energy optimization.