Empowering the Worldwide Retrofit Movement: The Significance of Quality Fans

Thomas Urban, Product Area Director, Fans & Accessories, Systemair Group, discusses what it means to have Systemair fans with the Green Ventilation label and how it can positively contribute to the broader retrofit trends and projects.


The need for efficient and more sustainable building performance is an increasing concern in Europe and many parts of the world. The trend has had substantial implications in new buildings, as well as in the retrofit landscape in the context of building renovations and energy efficiency improvements. Governments, organisations, and individuals recognise the importance of retrofitting existing buildings to reduce energy consumption, lower greenhouse gas emissions, and improve overall sustainability.

The European Union's Energy Performance of Buildings Directive (EPBD) has set targets for energy efficiency improvements in buildings, which has led to increased retrofitting efforts, especially following the launch of the Renovation Wave initiative in 2020, which aimed to double the annual energy renovation rate of buildings by 2030. Additionally, many European countries have implemented building energy performance certification schemes to assess and rate the energy efficiency of buildings. These certificates provide information to homeowners, tenants, and potential buyers about the energy performance of a building and encourage retrofitting to improve energy efficiency. Examples include Energy Performance Certificates (EPCs) in the UK and Energy Performance Certificates in France.

Against this backdrop, there is a need to raise awareness of how appropriate fan selection plays a critical role in meeting energy needs in retrofit initiatives and new buildings. Systemair’s Green Ventilation aims to provide a trustworthy environmental performance benchmark for its products as part of the company’s move to help customers find the optimal solution for their project needs. A critical aspect of Green Ventilation is a hands-on sustainability criterion for each product area, including fans.

Third-party certification

The importance of accurate and understandable technical documentation is essential to ensuring optimal functionality and efficiency of ventilation systems and facilitating fair product comparisons. Independent third-party organisations, like AMCA, play an important role in providing rigorous certification processes and building trust between manufacturers and customers. Thus, a critical benchmark of fan products with the Green Ventilation label is that they must be tested in an AMCA-accredited lab.

Thomas Urban Product Area Director Fans Accessories Systemair Group

Fans carrying the green ventilation label have proven performance which is ensured through rigorous sound and performance product testing in one of our AMCA-accredited laboratories or one of AMCA’s laboratories.

Thomas Urban
Product Area Director, Fans and Accessories, Systemair Group

Such bodies also address concerns about misleading practices in the market, such as inflated data, confusing engineering units, and incorrect performance representations. Systemair has had a rich history with AMCA, reflecting its commitment to meeting the larger goal of raising standards within the HVAC sector. In 1996, Systemair’s laboratory in Skinnskatteberg, Sweden, became one of Europe’s first AMCA-accredited laboratories for testing fans for air performance and sound and for the air curtains for air performance, velocity uniformity and velocity projection. Since then, Systemair has added three more AMCA-accredited laboratories to its portfolio in Germany, India, and the USA.

MUB with EC motor

Latest EC or AC motor technology

Under the Green Ventilation criteria, fans that carry the label must contain EC motors with an IE5 efficiency class or AC motors with an efficiency class of IE3 or higher. To provide a very basic clarification, Urban explains that AC motors use the main frequency to turn and an external frequency converter to determine the speed. In contrast, an EC motor is a brushless, permanent magnet motor with built-in electronics where an 0-10V signal can control the speed of the motor.

EC motors are very highly efficient motors and maintain high-efficiency levels even at part load, which successively leads into lower operating costs and short payback periods,” Urban says. “EC motors also have a wider operating speed range than traditional induction motors, which suggests that one EC motor can replace various induction motor models. In this way, the number of models a typical customer requires significantly decreases, reducing and simplifying inventory. This is the most common reason why EC motor product lines usually include fewer motor models than their induction counterparts.”

AXC-PV Fan with IE3 motor

Urban adds that because the motor’s operation is controlled by software, EC motors allow customers to optimise and integrate the motor, fan, and controller with the application and to incorporate features like data communications, constant volume control and variable speed. Also, EC motors are quieter than traditional inefficient motors and need less maintenance.

However, Urban ultimately advocates for customers to invest in the most efficient fan possible. “It´s not only about EC motors,” says Urban. ”Generally, you can also use standard IEC motors with an efficiency grade of IE3 or higher, depending on the power. In the end, it´s all about energy saving!” Urban adds that there is a need to make efficient fan selection mandatory worldwide.

We have one goal, and we all live on the same planet, so we should all make a conscious effort to move in a more environmentally-friendly direction. Unfortunately, in many countries and regions outside of Europe, especially in areas where energy is still cheap, the lack of minimum standards and regulations leads some people to choose an inefficient, cheap solution that will harm not only the sustainability of the project but also the environment.

No rare-earth magnets

Another critical aspect for fans with the Green Ventilation label is that no rare-earth magnets were used in its production. “Rare-earth magnets are made from non-renewable resources like rare-earth metals, which are mined directly from the Earth,” explains Urban.

This process causes significant destruction of the natural ecosystem. From a sustainability point of view, no rare-earth magnets should be used to create products.”

No belt drives

A final point and equally critical requirement for fans under the Green Ventilation label is that they must not contain belt drives. In a direct-driven fan, Urban explains that the impeller is directly connected or mounted to the motor (-shaft). “There are no power transmission losses,” he emphasises. “The energy that the motor develops is transmitted directly to the impeller. In a belt-driven fan, the motor exists independently of the fan blades or impeller, and at least one belt connects the motor to the fan´s moving part, such as the impeller or blades. As a result, too many losses occur when using a belt drive fan, resulting in low energy efficiency.”

Greater efficiency is the most significant advantage of direct drive fan configurations, says Urban, who adds that, unlike belt-driven fans, there’s less energy loss because there’s a reduced amount of friction as the fan operates. “There’s also no belt residue, and these fans cost less to maintain because belts don’t wear down and break,” he says. “Additionally, they’re easier to clean. A direct drive fan's footprint is also significantly smaller than a belt drive fan and, moreover, pushing for the use of direct drive fans is part of the energy regulation in Europe (ErP).”

Real-life applications

The benefits of choosing products with the green ventilation label cannot be denied. One such product is Systemair’s MUB EC fans. MUB EC Fans were recently used to retrofit the ventilation system in the Beckstein winegrowers’ cooperative in Germany, founded in 1894. To ensure the safety and comfort of people working on the premises, the decision was made to replace the ventilation system operating to extract fermentation gases from the cellar and provide an optimum oxygen supply.

Harald Rudelgass Q

Systemair was asked to provide a replacement fan unit. Our first inspection revealed that it was a very old fan, an axial fan–belt driven used in the early 1970s. Two state-of-the-art multi-boxes (MUB) with high-quality EC technology replaced this fan. If you look at the existing system, you can assume an efficiency of 58-60%. Now, products used in this project have motor efficiency levels of over 90%.

Harald Rudelgass
Group Product Compliance Director,
Systemair Group

The compact dimensions of the MUB Fans provided the customer with more valuable space freed up for production, and in addition, the noise levels have been reduced. A significant aspect of the decision, however, was energy savings. Urban says that the initially projected energy saving of 30% was already achieved in a short time.

Taking an operating time of 2.500h/year, the saving is approx. 7.500 kWh,” he says. “As such, depending on the previous system, approx. up to 50% energy saving is possible with fans meeting the green ventilation criteria.