Energy-Saving Retrofit Test of EC Fans for AHU Air Handling Units in Clean Workshop – Nearly 50% Power Saving, Cost Reduction Effect Far Exceeds Expectations

Within the production system of electronic manufacturing clean rooms, Air Handling Units (AHUs) operate nonstop 24 hours a day all year round. Stable constant temperature & humidity and air purification serve as the fundamental guarantee for production yield, making fan units impossible to shut down. Years of continuous heavy-duty operation expose traditional AC motor assemblies to numerous intractable pain points, which have become the core burden of factory energy consumption and maintenance costs.

ⅠBefore Retrofit: Multiple Pain Points of Conventional AC Fans Lead to Sustained High Operating Costs

1. Severe Energy Loss with Persistently High Electricity Bills

The workshop was originally equipped with 2 air handling units driven by conventional AC motors, each with a rated power of 22 kW, bringing a total rated power of 44 kW for the two units. AC asynchronous motors feature inherently low energy efficiency. Its belt and bearing transmission structure generates substantial extra mechanical losses. In addition, such motors fail to adjust rotation speed accurately according to real-time workshop loads and can only run at constant high power. The daily power consumption hits 801 kWh, resulting in massive monthly electricity expenses for each single AHU unit.

2. Aging & Corroded Equipment with Frequent Breakdowns and High Maintenance Costs

The clean zone inside the workshop has a humid environment. Conventional motors and transmission components operate under high temperatures year-round, making the equipment prone to rust and aging. Common faults include worn belts, abnormal bearing noise and motor overheating. To avoid production line shutdowns, the factory must regularly replace transmission parts and arrange staff for inspections and repairs. Fixed annual maintenance costs amount to several thousand yuan. Frequent maintenance shutdowns also pose risks of disrupting normal production in the clean workshop.

3. Poor Regulation Flexibility and Uncontrollable Wasted Energy

Old AC fans only support limited speed adjustment modes. They cannot dynamically match air volume with changes such as staff presence, production line startup/shutdown and temperature & humidity fluctuations in the workshop, maintaining full-load output all day long and generating massive unnecessary power consumption during low-load periods. Meanwhile, without digital power consumption recording tools, energy losses cannot be visualized and counted, making refined energy management across the plant impossible to implement.

In view of the above long-standing cost and equipment challenges, the plant launched an energy-saving pilot renovation project with a target of 25% comprehensive energy savings for the equipment. Upon achieving this target, the plant will fully roll out upgrades for all similar air handling units factory-wide.

II. Retrofit Solution: Full Unit Replacement with High-Efficiency EC Brushless DC Energy-Saving Fans

For this pilot project, the original complete AC motor and belt transmission assemblies were removed and uniformly replaced with integrated high-efficiency EC brushless DC fan units, whose total rated power stands at 32 kW.

Leveraging the core strengths of EC motors — zero transmission loss, stepless variable frequency precise speed regulation and high-efficiency operation under wide working conditions — the units can automatically adjust output power based on real-time temperature, humidity and cleanliness requirements of the clean workshop. After stable commissioning, the average actual operating power of the equipment dropped to merely 17 kW, and the daily power consumption after renovation fell to 408 kWh.

III. Measured Data Released: Tangible Cost-Saving Benefits

1. Rigorous Verification of Power-Saving Performance

Daily power saved: 801 – 408 = 393 kWh

Overall energy-saving rate: (801 – 408) ÷ 801 × 100% = 49.1%, cutting power consumption by nearly half.

2. Annual Comprehensive Cost Savings (Electricity price calculated at ¥0.75 / kWh)

Annual electricity cost saved: ¥106,188

Featuring belt-free design and low-wear construction, EC fans greatly reduce component abrasion, delivering an extra ¥4,000 saved on maintenance fees each year.

Total annual operating expenditure saved per single AHU unit exceeds ¥110,000.

IV. Plant Feedback: Results Far Surpass Expectations, Mass Plant-Wide Renovation Scheduled

The original evaluation benchmark set by the plant for the renovation was merely a 25% energy saving rate. However, the measured energy-saving rate of this pilot retrofit reached an impressive 49.1%, with power-saving outcomes greatly exceeding management’s expectations.

The plant has now formulated an overall upgrade plan. In the follow-up phase, energy-saving replacement with EC fans will be carried out in batches for dozens of identical AHU air handling units and other central air conditioning units across the factory. This initiative will systematically cut the plant’s total energy consumption and build a low-carbon clean production workshop.

Ventilation and air conditioning equipment that requires round-the-clock continuous operation, including electronic dust-free clean workshops, biopharmaceutical purification plants, data center cooling systems, central air conditioning for large shopping malls, AHU air handling units and fresh air purification units for industrial plants, can achieve substantial energy and power consumption reduction through replacement with EC fans.

Retrofit and upgrade of traditional high-energy-consumption fans serves as an optimal solution for manufacturing enterprises to cut costs, boost efficiency and realize green production. With one-time investment in renovation, factories can sustainably save electricity and maintenance expenses over the long term, balancing corporate production cost control with low-carbon and eco-friendly production requirements.