01 Project Background: Silent Operation Becomes a New Competitive Advantage for Medical Equipment

With the continuous advancement of medical technology, medical imaging equipment has become an essential tool for early disease detection, accurate diagnosis, and treatment support.

In recent years, medical equipment manufacturers have focused not only on improving:

• Image processing performance
• Diagnostic accuracy
• Equipment reliability

but also on enhancing the overall user experience for patients.

Especially for medical imaging equipment used near patients, operating noise has become an important factor affecting comfort and confidence during examinations.

Therefore, when developing a new model of medical imaging equipment, N Company identified:

“Reducing operating noise”

as one of the key product differentiation goals.

02 Customer Challenge: Reducing Fan Noise While Maintaining Cooling Performance

To reduce equipment noise, N Company first focused on improving the cooling fan.

The engineering team selected several cooling fans based on catalog specifications, including:

• Low-noise models
• High-reliability models

However, during actual equipment testing, they encountered an unexpected challenge.

Although some fans achieved:

• Lower operating noise

after installation, they also caused:

• Insufficient cooling performance
• Higher internal temperatures

On the other hand, fans with stronger cooling capability:

• Provided sufficient airflow

but:

• Could not achieve the required noise level.

N Company discovered that:

Simply selecting a low-noise fan does not guarantee optimal performance in the actual equipment.

03 Selection Challenge: Catalog Specifications Cannot Fully Represent Actual Operating Conditions

Cooling fan catalogs generally provide specifications such as:

• Maximum airflow
• Maximum static pressure
• Noise level

However, these values are measured under standardized test conditions.

Once a fan is installed inside actual equipment, its performance can be affected by:

• Enclosure structure
• Airflow path design
• Internal component layout
• Airflow resistance

As a result, the same fan may perform differently depending on the equipment design.

Therefore, N Company faced a critical question:

How can engineers quickly identify a cooling fan that achieves both low noise and sufficient cooling performance during the development stage?

To address this challenge, SANYO DENKI engineers did not simply recommend a fan model.

Instead, they first analyzed the actual airflow environment inside the equipment.

Using:

Airflow and Pressure Measurement System

SANYO DENKI engineers measured the airflow characteristics of N Company's prototype medical imaging equipment.

Through the measurement process, they obtained:

System Impedance Data

System impedance represents:

The resistance to airflow inside the equipment.

For example, system impedance increases when:

• Airflow paths are narrow
• Internal structures are complex
• Exhaust resistance is high

05 Technical Key Point: Identifying the Fan Operating Point

A cooling fan does not operate according to its maximum airflow or maximum static pressure values shown in the catalog.

The actual operating condition is determined by the intersection between:

Fan Performance Curve

and

Equipment System Impedance Curve

This intersection is called:

Fan Operating Point

By identifying the operating point, SANYO DENKI engineers could accurately evaluate:

• Actual airflow
• Actual static pressure
• Actual operating noise

This approach helps avoid a common issue:

Selecting a fan based only on catalog specifications, but finding that the actual performance is insufficient after installation.

06 Fan Solution Optimization: Achieving 10 dB Noise Reduction

Based on the measurement results, SANYO DENKI analyzed multiple fan solutions.

The final recommendation was:

Fan B Solution

Although Fan B did not appear significantly superior to the existing Fan A when comparing only catalog specifications, the operating point analysis revealed important differences.

Under actual equipment conditions, Fan B provided:

• Higher effective airflow
• Sufficient static pressure
• Lower operating noise

N Company then conducted an actual equipment evaluation.

The test results showed:

Operating noise was reduced by approximately 10 dB.

At the same time:

• Cooling performance requirements were satisfied
• Stable equipment operation was achieved
• The silent operation target was successfully accomplished

As a result, N Company decided to adopt the recommended fan solution.

07 Project Results: From Trial-and-Error Testing to Data-Based Fan Selection

Through this project, N Company not only solved the cooling fan selection challenge but also gained a more efficient approach to thermal design.

Project achievements:

08 Further Value: Thermal Design Needs to Evolve from “Fan Selection” to “System Design”

For medical equipment, inspection devices, and precision instruments:

A cooling fan is not simply a replaceable component.

An effective thermal design requires comprehensive consideration of:

• Internal airflow paths
• Heat source distribution
• System impedance
• Fan operating points

By measuring airflow and pressure characteristics, engineers can understand the actual cooling conditions at an early development stage.

This allows fan selection to evolve from:

“Testing until the right fan is found”

to:

“Measuring, analyzing, and verifying the optimal solution.”

Conclusion

For medical equipment applications where low noise and high reliability are essential, the best cooling solution is not simply choosing the most powerful fan.

The key is finding:

The cooling fan that best matches the actual operating conditions of the equipment.

Through professional measurement technology and engineering support, SANYO DENKI San Ace helps customers achieve:

Low-noise, highly reliable, and efficient thermal designs.