Advertorial - EC fans vs VSDs: which is better?

EC Fans Image

Carl Turbitt, HVAC Drives – UK Sales Manager, ABB, explains why when it comes to deciding between EC fans and a variable speed drive and motor solutions, comparing efficiency alone will not provide the full picture.

When considering the merits of Electronically Commutated (EC) fans versus variable speed drive and motor solutions in HVAC applications, it is easy to assume that an EC fan’s higher efficiency and lower payback make it the more cost-effective option. However, considering efficiency alone loses sight of the bigger picture in deciding which technology is a better fit for a given installation.

Installation and maintenance


EC motors are typically made to order and sized for a particular application, so are not always sized in traditional IEC dimensions. In the event of a fault, this can make sourcing spare parts more difficult, and even result in the whole fan requiring replacement, leading to higher life cycle costs. A traditional electric motor powered by a VSD achieves comparable efficiency, plus they use standardised parts and sizes, allowing easier maintenance, often via local service providers.

Total Cost of Ownership


Choosing based on efficiency alone fails to consider the requirements of HVAC applications. System designers need to consider the integration of components with other equipment. VSDs provide integrated I/O connectivity, along with HVAC-specific macros and PID control, allowing flexibility to adapt control systems to the needs of the building, while providing connectivity and compatibility with building management systems. ABB VSDs include embedded BACnet and Modbus communications, removing the need for gateways and additional costs down the line.



Energy usage is not the only measure of efficiency. Using a VSD allows for more economic use of panel space thanks to Engineering Optimisation, whereby the VSD’s functionality renders many typical cabinet components redundant, allowing them to be removed altogether. This reduces purchase, operational and maintenance costs. Modern VSDs can replace thermostats, timers, relays, safety contactors, external HMIs, Isolators and energy management tools that would typically be carried out by discrete devices.

To learn more about VSDs and how they stack up against EC fans, download our white paper with the link below.

To sign up to our “EC Fan v’s Induction motor technology overview” seminar, contact Carl Turbitt directly at, on 01925 741111, or find him on LinkedIn.

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