In automotive and industrial paint booth applications, ventilation performance directly impacts coating quality, production efficiency, and operational costs.

However, many aging Air Handling Units (AHUs) struggle to maintain stable airflow and precise climate control as fan performance declines over time. Increased energy consumption, frequent maintenance, and unexpected downtime become common challenges — especially for facilities operating continuously.

When an AHU begins to show its age, many building owners assume the only solution is a complete replacement. But in many cases, the most effective upgrade starts with the fan system.

A recent AHU retrofit project in Argentina upgraded four paint booth ventilation systems with 69 EC fans, delivering up to 658,500 m³/h of airflow while improving climate control, operational reliability, and maintenance efficiency.

The Challenge

The existing AHU had been operating reliably for years, but the fan system was no longer meeting today's expectations for energy efficiency, controllability, and maintenance.

Like many older installations, it relied on a traditional belt-driven AC fan configuration, resulting in:

Replacing the entire AHU would have required substantial investment and operational downtime.

Instead, the project focused on upgrading the component with the greatest potential for improvement.

The Retrofit Strategy

Rather than replacing the complete air handling unit, the engineering team retained the existing AHU structure while upgrading the fan section with modern EC fan technology.

This approach preserved the original ventilation capacity while delivering a more efficient and intelligent airflow solution.

Compared with conventional belt-driven systems, EC fans provide:

Pic.1 What can EC fans provide?

By modernizing only the fan system, the project achieved a significant performance upgrade without replacing the entire AHU.

Pic.2 The new ventilation systems’ fan grid (Source|ebm-papst Argentina SA)

More Than Energy Savings

The benefits extended well beyond reduced electricity consumption.

The retrofit also delivered:

• Improved airflow control

• Lower operating noise

• Reduced maintenance requirements

• Higher system reliability

• Greater operational flexibility

• Better long-term life-cycle value

For facilities operating continuously, these improvements can have a meaningful impact on both operating costs and occupant comfort.

Pic.3 The new control system ensures an optimum indoor climate in the paint booths(Source|ebm-papst Argentina SA)

A Growing Trend in Commercial HVAC

As commercial buildings pursue higher energy efficiency and sustainability targets, more owners are reconsidering whether complete equipment replacement is always necessary.

In many retrofit projects, upgrading the fan system has become one of the most practical ways to improve HVAC performance while minimizing capital expenditure and installation disruption.

It's a strategy that aligns well with today's focus on lifecycle cost rather than simply initial investment.

Let's Discuss

When evaluating an aging AHU, would you replace the entire system—or modernize the components that have the greatest impact on efficiency and performance?

At Beijing Hengrui, we work with building owners, HVAC contractors, AHU manufacturers, EPC companies, and consulting engineers to assess retrofit opportunities and develop practical EC fan upgrade solutions for commercial buildings and industrial facilities.

We'd be happy to exchange engineering insights from real-world retrofit projects.