The Benefits of Specifying Systemair Air Handlers With EC Motors
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One of the most important technologies for HVAC systems has been the proliferation of EC (electrically commutated) motors to replace the more traditional AC motor. Testing reveals that switching from an AC to an EC motor results in fans that are more efficient, are quieter, and last longer. As part of our ongoing efforts to specify the highest quality, most efficient equipment, Systemair uses EC fans in all of our air handling units—Topvex, Changeair, and Geniox.
The benefits of the EC motor stem from its built-in electronics. EC motors provide stricter control of the fan’s speed and adjust motor speed to fit the actual ventilation need. Many of today’s sensors work with a 0-10v signal, making it easy to combine the needed sensor for a specific application with a ventilation unit equipped with EC motors to achieve demand-controlled ventilation. Because of the EC fan’s built-in electronics, speed control is easier.
These attributes provide a host of benefits, including:
Greater energy efficiency: Our sister company Fantech recently conducted a study on two of its fans—the KVKE 250 M circular duct fan and the KVKE 250 EC circular duct fan, which has an EC motor. The results showed that the EC fan used 62% less power, requiring 89 W compared to the AC fan’s 143 W.
Part of these savings is due to the speed control. An AC fan uses frequency control, while the EC fan uses a 0-10v signal.
In addition, power is proportional to the cube of a fan’s shaft speed. Consider an application with eight 100 W fans. With AC fans, we can shut down four fans to reach 50% of the ventilation need, reducing total power usage to 400 W. But what if in that same application we instead regulated the speed of all eight fans to 50%. This results in each fan using 12.5 W for a total use of 100 W for the same ventilation rate.
Fewer components: To step down AC fans requires a VFD. An EC fan eliminates the need and cost for that additional component.
Lower operational cost: Efficiencies netting as much as 90% provides for operational cost savings.
Longer life span: Along with efficiencies, speed control on an AC motor also creates additional heat, which will burden the motor, especially the bearings. Because an EC fan’s speed is controlled through a 0-10v signal, its motor does not experience heat buildup. This also helps decrease installation and maintenance costs, and also reduces the risk of onsite faulty connections.
Versatile for air handling units: Because EC fans use an external rotor motor, they are extremely compact. Combine this with high efficiency, and EC fans are ideal for configuring into compact Geniox air handler units without compromising energy consumption.
Easy installation: Most Systemair EC fans come with a potentiometer to ease installation and speed control. This means that the preferred working point for the fan can be found easily without any additional wiring. Setup for an EC fan is easier than conventional units, offering plug-and-play setup with only a 0-10v signal and power supply. There’s no need for additional components, as shown in this diagram:
Another advantage of the external rotor motor is low maintenance; it requires inspection just once a year.
Stepless speed control allows the unit to run in the designed operation point and to be operated by ventilation on demand. The fan provides exactly the amount of supply air that is needed due to CO2, RH, or VOC level, increasing comfort and optimizing system use.
There are some instances where AC fans are required, and Geniox air handlers can accommodate those, as well.
Learn more about Systemair’s Geniox and Geniox+ air handlers.