A Whole House Fan Company
A Whole House Fan Company
The German Engineered ebm-papst EC fans use as little as 1/3 of the energy used by today’s industry standard fans.
Most fans used in commercial applications are AC fans. ebm-papst EC fans are Electronically Commutated (hence the EC of the title) DC fans. This difference is at the heart of the energy savings.
In an ordinary electric motor the rotation inside the motor is created using the alternating current (AC) of the power supply. Alternating current is a waveform that, as the name implies, constantly swings from positive to negative and back to positive. This swinging, or ‘alternating’, creates alternating magnetic fields, which, in turn, create a second set of alternating magnetic fields inside the motor. This second set is what spins the motor’s rotor – what makes it go.
On the face of it, this seems a sensible use of the unstable nature of AC power. It certainly works. The problem, in today’s energy-conscious world, is that it is a fundamentally inefficient process. A considerable amount of the energy going in to the motor is lost, these electrical losses are evident in the heat given off by the motor.
ebm-papst EC motors, in contrast, use permanent magnets to create the magnetic field inside the motor and electronically switched (or ‘commutated’) direct current (DC) to create the rotation. This is inherently a much more stable design, with much lower losses.
Traditional DC motors also had this advantage, but were unpopular due to the short life expectancy and high maintenance costs of mechanical commutation (brushes).
Electronic commutation allows you to control the speed of the motor in a very efficient way.
The speed of a motor’s rotation is defined by how fast the magnetic fields inside the motor alternate. In an AC motor, that speed is determined by the frequency of the alternating current. Obviously, the motor is not limited to just one speed, but it does mean that AC motors are designed to operate at a particular speed. The efficiency of the motor drops markedly as the motor moves away from that speed.
The speed of an EC motor, on the other hand, is governed by the switching of the electronics. This means, that the ability to control speed is automatic in an EC motor. It also means that an EC motor runs at near full efficiency whether it is at start-up, full speed or any speed in between. Where speed control is required, this gives EC products an even bigger efficiency advantage.
