Escaping the rust belt

The persistent use of belt-driven fans despite the availability of more sustainable solutions in the market.


Morten Schmelzer, Technical Marketing Director, Systemair Group, writes on the factors contributing to the persistent use of belt-driven fans in some areas of the world, despite the availability of more sustainable solutions in the market.

Morten Schmelzer

In many parts of the world, belt-driven fans are still the rule rather than the exception. This is despite direct-driven fans‘ availability, which proves to be a more energy-efficient solution that contributes to more sustainable operations.

Simple physics confirms that belt-driven fans are inefficient in energy consumption compared with modern solutions such as EC plug fans, a direct-driven fan motor combination.

It is also known that belt drives can pollute the supply air stream and harm products such as Air Handling Units due to problems such as rubber residue. The best options available on the market to date are fans with highly efficient EC motor technology.

Admittedly, there are few and specific instances where belt-driven fans may be suitable. For example, if you face a high external static pressure or high total static pressure, a plug fan can have trouble coping with it. This becomes valid as of roughly 1200Pa total static pressure, which requires the scroll housing to transfer dynamic pressure into static pressure. However, outside of this scenario and in most applications, the use of a belt-driven fan is simply inexcusable, especially when we consider the available technologies in the market and the global drive to mitigate the carbon emissions from the built environment.

Currently, the use of belt-drive fans is most common in regions of the world where there is further scope for improvement in terms of minimum energy performance standards and legislation. This includes, for example, many countries in Asia, Africa, the Americas and Middle East.

In such areas, there are limited regulatory boundary conditions that prevent the utilisation of belt-driven fans. If there are requirements, they tend to be low, allowing belt-driven solutions to enter the market without any issues.

As long as belt-driven products are available as an option in the market, customers tend to choose them.

Morten Schmelzer
Technical Marketing Director, Systemair Group

This is sadly the case since, typically, the outdated and least efficient solution also tend to be the cheapest one. And in the fight to increase profit margins, projects opt for the low-cost option without considering the long-term operational cost incurring from choosing the less efficient product. Initial price matters. However, in the long run, cheaper solutions such as belt drives will always end up costing more, owing to its higher electricity consumption and because it will most likely require replacement sooner.

Lack of education is another aggravating issue outside of cost. In some cases, customers are used to belt drives and unaware that today‘s solutions are much more beneficial. There is a general lack of awareness about the negative impact belt-driven fans can have, and habits have persisted, leading to older technologies out of familiarity. This also means that specifications are often not adapted over time. The exact specification requirements are copied year after year, without considering the latest state-of-the-art technological innovation and standards.

Once energy performance and health requirements become stricter, market forces tend always to find a solution. In the European Union, through the so-called Ecodesign Regulations, belt-driven fans are barely ever utilised anymore.

Just two decades ago, no one would have thought that fans placed on the European market would ever reach such an incredible degree of efficiency at a minimum noise level. Yet, the market has completely transformed and innovated due to applied boundary conditions.

There is a need for more robust engagement among industry associations for other regions and fan certification schemes to rate energy performances better. Action must be taken to educate the market and encourage best practices with a long-term mindset that values operational cost rather than focusing on capital cost and sustainable contributions over short-sighted gains.