Table of ContentsSection 15: Fan Types & Design Guidelines................................................................................2

15.1 Definition of EC:..........................................................................................................2

15.1.1: Advantages of EC technology:.....................................................................................2

15.2 Definition of Plug Fan:.................................................................................................2

15.3 Comparison between EC vs. (VSD and traditional) Fan:..............................................3

15.4 Performance curve of Plug Fan:..................................................................................5

15.5 characteristic data for PLG fan model:........................................................................5

Section 15: Fan Types & Design GuidelinesPlug Fan – (EC Fan)

15.1 Definition of EC: EC stands for ‘Electrically Commutated’ and refers to the type of motor used to drive the fan.

Electrically commutated motors are brushless, direct current, external rotor type of motor. In commutation electronics, an AC voltage is changed into a direct voltage by a commutator.

The EC motor is actually a DC motor that can be connected to an AC supply line because there is a rectifier inside the motor drive. Speed control is achieved by varying the voltage direct current from zero to 10.

15.1.1: Advantages of EC technology: - Very high degree of efficiency.- Integrated controller (continuous control).- Very simple connection.- Additional functions (pressure control, etc.).- Smaller-sized motor for the same level of performance.- Less power consumption (Tremendous energy savings of 30 % on average).- Easy 1:1 replacement from AC technology to EC technology.

15.2 Definition of Plug Fan:

Plug Fan refers to the type of fan and how it is mounted.

Unlike VSD fan EC fan more efficient when the cooling units are running fully loaded, because VSD are limited to reducing fan speed up to 80%.

EC Plug fans use a different method to move air than the more commonly used scroll fans. Scroll fans have many tiny airfoils that ‘bite’ into the air forcing it downward. The airfoils, or blades, are called “forward inclined blades”. Plug fans use backward inclined blades. This blade design allows plug fans to draw air through the middle of the fans and ‘throw’ the air out horizontally. The backward inclined fan design for plug fan is inherently more efficient than forward inclined fan which is one reason why plug fans are required.1

1 http://www.dchuddle.com

Another benefit of the plug fan you can install it under a raised floor and that allow more even air distribution compared to the scroll fans which force air directly downward against the slab floor. The path of the air flowing through unit with plug fans is much smoother incurring less resistance than with scroll fans as shown below.2

15.3 Comparison between EC vs. (VSD and traditional) Fan:

Comparison between EC and VSD technology

Comparison between EC and traditional technologyFigure 1: Comparison between EC vs. (VSD & traditional) Fans:3

2 http://www.dchuddle.com3 Cooling solutions for IT equipment, Schneider Electric Industries SAS & Emerson Network Power | Energy Efficiency Solutions for Your Data Center.

Figure 2: Choosing between EC and VSD technology4

Choosing between EC and VSD technology

4 Cooling solutions for IT equipment, Schneider Electric Industries SAS & Emerson Network Power | Energy Efficiency Solutions for Your Data Center

15.4 Performance curve of Plug Fan:5

Performance curve

15.5 characteristic data for PLG fan model:

Operation temp. range ℃ Up to 427Volume m3/sec 0.283 – 33.036

Maximum static pressure Pa 1992.7

5 GREENHECK, Building Value in Air, PLG Model Catalogue, 2013