Efficiency in Fan Coil Units

EC Forward Curved Fans for Fan Coil Units


EC forward curved fans manufactured by Ecofit are the popular choice for integration into fan coil units that form part of the HVAC system in new and refurbished buildings. Fan coil units in new builds are generally fitted into the ceiling and recirculate the air inside the building. The fan coil unit is connected to a heating or cooling coil or both and as the air is drawn into the unit it is filtered to remove any particles of dust. The air is then forced through the heating or cooling coils to alter the temperature of the air accordingly before it is distributed back into the building via smaller ducting pipes in the system.



Typically fan coil units use between two and five fans to allow each fan to be run at lower speeds which has several benefits:



Fan failure MonitoringThe efficiency of the unit can only be maintained if fans are all running together at their desired operating points. When a fan fails the other fans must then speed up to ­­pick up the duty. With this in mind we can appreciate the importance of monitoring fan units for fan failures. The Ecofit M41-A5 from Axair has on board failure monitoring, this benefit is an add on for other manufacturers making the unit a cost effective and effective choice when installing this type of application.

The most popular option for fan coil monitoring is a taco output, which generally come as standard with most manufacturers EC motor ranges. The problem with using taco monitoring is that multi-fan systems within a plenum arrangement are systems of two halves. The inlet side is under a constant low pressure and the discharge side under constant high pressure. As soon as a fan fails and begins to slow down, the taco pulse also slows until the unit stops and runs in reverse. Taco monitored systems will not show fan failure until either the motors are locked, there is a complaint that the unit has lost performance or there is too much noise as one or more fans run full speed to try and pick up the duty lost when most of the fans are failed, causing an inefficient system and high noise levels.

UK building legislation requires system designers to comply with the latest energy efficiency guidelines when designing a new system or upgrading an existing, outdated system.  New systems must be designed and built to the highest efficiency resulting in a low environmental impact.  A fan coil unit must be installed correctly and well maintained in order to provide efficient air conditioning and effectively regulate the temperature of the building or room its situated.  A unit that is over 20years old is likely to be less efficient and non-compliant with the latest energy guidelines. Therefore it is advised to upgrade the system with new energy efficient fans or replace the system entirely. However, it can be costly to completely replace the unit, so it is often the preferred choice to retrofit an existing system with replacement EC fans.


Fan coil manufacturers should be looking at integrating EC fans over the standard AC versions to reduce energy consumption in line with the current energy efficiency regulations for buildings. Our double inlet double width EC centrifugal fans manufactured by Ecofit are a popular choice for heating and ventilation and offer over 90% more efficiency with up to 50% energy savings compared to conventional motors. Integrating EC fans can help towards reducing your overall energy usage, outgoing costs and contributes to reducing your overall environmental impact.


EC forward curved fans can easily be wired into an existing FCU and have many benefits such as adjustable speed settings which can be set during or after installation and will remain constant. The integrated controller allows for constant pressure and airflow modes in which case the fan will self-regulate its speed based on the demand settings under the changing conditions. This ensures there is no loss in performance as filters fill up. EC motors are maintenance free with minimal noise output making them the perfect solution for daily occupied spaces.

Many buildings are now Passivhaus certified, adhering to a strict criteria in line with future sustainability and net zero goals. Learn more about the Passivhaus standard here.



The GDS, GDR & GDF range of forward curved Ecofit fans from Axair are available in various configurations including taco output, built in monitoring alarm, Constant pressure or constant volume monitoring with no additional bolt ons required. Contact us on 01782 349430 for more information.