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EU focuses on “green” fans

ErP direc­tive demands high effi­ciency

By adopting the Kyoto Protocol, the Euro­pean Union has under­taken to reduce CO2 emis­sions by at least 20% by 2020. One measure for achieving this is the EuP direc­tive (Energy-using Prod­ucts direc­tive) adopted by the EU in 2005, which was renamed the ErP direc­tive (Energy-Related Prod­ucts direc­tive) in 2009 and is also referred to (in Germany) as the eco-design direc­tive. Within its frame­work, the savings poten­tial of energy-rele­vant prod­ucts are exam­ined and minimum require­ments are defined. For example, in the field of lighting, this has already had concrete impact: 100W bulbs are due to disap­pear from the market. Now, manda­tory limits applic­able for fans were defined in June 2010.
When the ErP direc­tive becomes effec­tive for fans, fan manu­fac­turers will be required to design their prod­ucts for the Euro­pean market to comply with defined effi­ciency stan­dards to make an impor­tant contri­bu­tion to reducing energy consump­tion. This will affect all fans in the power range from 125 W to 500 kW, regard­less of whether or not they are oper­ated as single units or as inte­grated compo­nents within a system. This concerns all conceiv­able appli­ca­tions, from refrig­er­a­tion and air-condi­tioning tech­nology through to mechan­ical engi­neering and IT appli­ca­tions.

Two-stage plan with strict stan­dards

To decide whether a fan satis­fies the ErP Direc­tive, the effi­ciency of the complete fan is assessed, i.e. the unit of control elec­tronics (if fitted), motor and fan impeller

The EU has spec­i­fied a two-stage plan with strict stan­dards to keep “energy-burners” off of the Euro­pean market in the future. The first stage will become effec­tive on 1 January 2013. Some 30% of all fans currently on the market will then no longer satisfy Euro­pean regu­la­tions. In the second stage, from 2015, another 20% will be replaced by more effi­cient prod­ucts. These will satisfy the spec­i­fied minimum effi­ciency levels.
The user can recog­nise fans that satisfy the require­ments of the direc­tive by the CE sign, which will then give energy effi­ciency the same signif­i­cance as compli­ance with the low-voltage and EMC direc­tives. Labelling in the way prac­ticed with washing machines, refrig­er­a­tors etc. is not planned for fans as the fan manu­fac­turers usually have no influ­ence over the instal­la­tion condi­tions.

Chal­lenging limits

The effi­ciency cloud shows that many fans exceed the values demanded

To decide whether a fan is compliant with the ErP direc­tive, the effi­ciency of the complete, ready-to-use fan is assessed, i.e. the unit comprising control elec­tronics (if fitted), motor and fan impeller. The corre­sponding limits have been set very high. The effi­ciency cloud illus­trates the limits that are set to become valid in 2013 and 2015, shown in the form of black lines. At the same time, the effi­ciency of conven­tional centrifugal fans from ebm-papst’s broad product range are entered in the diagram. The “effi­ciency cloud” shows that not all fans satisfy the future require­ments. But it can also be seen that for every fan that will no longer be permitted in the future, there is already an energy-effi­cient replace­ment that not only fulfils the spec­i­fi­ca­tions of the direc­tive, but actu­ally exceeds them.
For axial fans, forward and back­ward curved centrifugal fans, tangen­tial blowers and diag­onal fans, the EU has spec­i­fied the corre­sponding formulas with which the respec­tive minimum effi­ciency can be calcu­lated. In the assess­ment, different power ranges and mounting condi­tions are taken into account for the measure­ments. The target effi­ciency, that is the concrete spec­i­fi­ca­tion for an axial fan in the power range from 0.125 to 10 kW, can be calcu­lated using the following formula:

To deter­mine the effi­ciency, the EU spec­i­fies the rele­vant formulas that are used to calcu­late the minimum effi­ciency for each type of fan

Minimum effi­ciency ηmin = 2.74 x ln (power input P1 in kW) – 6.33 + N. Where N is a constant defined in the direc­tive. For axial fans, this will have the value 36 from 1 January 2013 and 40 from 1 January 2015. This factor can be looked upon as a kind of polit­ical “setting screw” for a further tight­ening of require­ments in the future. For the HyBlade® axial fan illus­trated in Figure 4 with a drive output of 0.69 kW at optimal oper­ating point, the formula states that an effi­ciency of at least 28.65% must be achieved from 2013 and at least 32.65% from 2015, based on the static pres­sure increase. The curve indi­cates 40% effi­ciency, which is already substan­tially higher than the minimum require­ment for 2015. This fan thus already satis­fies the future spec­i­fi­ca­tions.

The future belongs to EC tech­nology

HyBlade® axial fan in EC tech­nology, which not only fulfils the strict energy effi­ciency require­ments, but actu­ally substan­tially exceeds them

The effi­ciency cloud shows exam­ples of just how demanding the limits spec­i­fied by the ERP direc­tive are. Against this back­ground, the EC tech­nology devel­oped some years ago by ebm-papst is the first choice for elec­tri­cally powered fans. Compared to conven­tional fans with asyn­chro­nous motors (AC tech­nology), EC motors achieve an effi­ciency of more than 90%. That means energy consump­tion up to 50% lower compared to AC solu­tions. More­over, the speed of EC fans can be controlled so that the air volume can be adapted to suit the specific require­ments, which also results in further substan­tial energy savings.
Thanks to the successful inter­ac­tion of motor, elec­tronics and aero­dy­namics, ebm-papst’s EC fans do not just convince with respect to their energy effi­ciency. They also work extremely quietly thanks to their opti­mised commu­ta­tion tech­niques and the aero­dy­namic config­u­ra­tion of the impellers. And on top of every­thing, they also convince with their reli­a­bility and dura­bility.

Direc­tive for motors

EC motors (green) substan­tially exceed the effi­ciency level required by the direc­tive for AC motors (other colours)

What applies to fans also applies in prin­ciple to elec­tric motors. In this context there is often a lack of clarity leading to misun­der­stand­ings. The fact is that elec­tric motors are required to achieve at least effi­ciency class IE2 from June 2011 in accor­dance with Euro­pean Union direc­tive no. 2009/640/EC (ERP direc­tive). Only then will these motors be permitted to remain on the market in Europe. However, not all of the stan­dard motors today will be affected by this direc­tive. The direc­tive defines a “motor” as an “elec­tric single speed, three-phase 50 Hz or
50/60 Hz, squirrel cage induc­tion motor that has 2, 4 or 6-poles, a rated voltage of up to 1000 V and a rated output between 0.75 kW and 375 kW”. EC external rotor motors like the ones used to drive energy-effi­cient fans are there­fore not subject to this direc­tive. Never­the­less, their effi­ciency can still be compared to the values stip­u­lated in the direc­tive. Here, it becomes clear that EC motors already substan­tially exceed the effi­ciency levels demanded. This shows that EC motor tech­nology is the better alter­na­tive when plan­ning energy-effi­cient devices and instal­la­tions.

Learn more about the ERP direc­tive

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