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FanGrid: More air perfor­mance and high energy effi­ciency

New Plug Fans exceed today the require­ments of tomorrow


With the coming into effect of the ErP (Energy related Prod­ucts) Imple­men­ta­tion Direc­tive for fans, manu­fac­turers are required to design their prod­ucts for the Euro­pean market in compli­ance with defined effi­ciency stan­dards. These stan­dards affects all fans in the power range 125 W to 500 kW, regard­less of whether or not they are used as stand-alone units or as compo­nents within another item of equip­ment or system. Great savings poten­tial can be achieved with the fans employed in venti­la­tion air-condi­tioning tech­nology, for these are often run with a high oper­ating factor. Modern fans with energy-effi­cient EC tech­nology have numerous advan­tages here. Not only do they satisfy both current and future manda­tory require­ments, they actu­ally exceed them by far, even today. This is equally bene­fi­cial to the envi­ron­ment and to the consumer’s purse.

Gallery: the new Plug Fans series

For energy-effi­cient use in venti­la­tion and air-condi­tioning tech­nology, ebm-papst Mulfingen has devel­oped the so-called Plug Fans series of fans with Green­Tech EC tech­nology, which has already been success­fully estab­lished on the market. In order to cover higher air perfor­mance ranges, the existing range has been extended upwards. Now, the back­ward curved centrifugal fans with impeller diam­e­ters ranging from 250 to 900 mm and power output ranging from 400 watts to 6 kilo­watts cover prac­ti­cally every feasible appli­ca­tion in the field of venti­la­tion and air-condi­tioning tech­nology. The volume flow that can be achieved is between 300 and approx­i­mately 30,000 m³/h with the neces­sary pres­sure increase of up to 1200 Pa. Typical appli­ca­tions include the cooling of large inverters in the field of photo­voltaics or for cooling the gener­a­tors on wind turbines. The fans are avail­able with a special corro­sion-resis­tant hygienic coating, enabling them to be used in hospi­tals and swim­ming pools without further ado.

Modern EC tech­nology and thought-out design details

Plug Fans are also avail­able with a special corro­sion-resis­tant hygienic coating

With the devel­op­ment of the series, the overall effi­ciency of the fans has been opti­mised with respect to the current and expected future minimum effi­ciency stan­dards. This was made possible by the choice of mate­rials, by thought-out design details and by the use of the latest EC tech­nology in the drives. Motor, elec­tronics and impeller are opti­mally config­ured in order to achieve maximum overall effi­ciency and mate­rial usage, and to avoid unnec­es­sarily large dimen­sions. For example, the blade geom­etry of the impeller with diag­onal trailing edge improves the aero­dy­namic char­ac­ter­is­tics and the running smooth­ness. The same thing applies for the vent contours realised on the new series. Previ­ously, a stan­dard pres­sure tap was inte­grated here to regu­late differ­en­tial pres­sure via a threaded nipple. A ring circuit is possible on request. The posi­tion of the impeller on the external rotor motor has been chosen to produce both aero­dy­namic advan­tages and instal­la­tion advan­tages.

The motors also satisfy the very highest stan­dards. Even today, the EC drives used in the Plug Fans are just as effi­cient as motors of effi­ciency class IE4. In other words they exceed by far the current require­ments of the ErP Direc­tive with respect to effi­ciency. The inte­grated elec­tronic control system allows their speed to be adapted contin­u­ously to the require­ments and enable them to work extremely effi­ciently. They thus consume far less energy than AC drives with the same air perfor­mance. However, this energy saving poten­tial is not only realised in full load oper­a­tion, but primarily when they are oper­ated under partial load. Noise devel­op­ment is very impor­tant in connec­tion with venti­la­tion and air-condi­tioning units. Here too, EC drives are the better choice, because they do not produce any motor noise in a controlled state.

Compact and easy to install

The effi­ciency plume shows that the fans exceed the required values

Another advan­tage of Plug Fans is their compact design. The elec­tron­i­cally commu­tated external rotor motor is inte­grated directly in the impeller. A belt drive between the motor and the fan, which is other­wise commonly used, is not needed (see Fig. 5). This reduces the neces­sary instal­la­tion volume. This effect is always desir­able, espe­cially in venti­la­tion and air-condi­tioning units; firstly because the air-condi­tioning unit can be made smaller, so it needs less mate­rial, and secondly because it reduces the amount of space it needs. Machine rooms etc. can then be designed to be smaller from the very begin­ning. At the same time, fewer parts are subject to wear and less main­te­nance is needed compared to belt-driven systems, keeping service costs down in the long term. The elec­tronics inte­grated in the motor also have another prac­tical benefit. The elec­trical connec­tion only needs an unscreened wire.

Plug Fans are avail­able in various instal­la­tion versions, e.g. with a “spider mounting” or with a fitted mounting plate for simple anti-vibra­tion mounting. The power elec­tronics inte­grated in the EC motors are compat­ible with all common supply volt­ages; depending on the motor type, either from 200 V to 277 V for single-phase AC or 380 V to 480 V for three-phase current supply. All versions work with a frequency of 50 or 60 Hz. Air perfor­mance and effi­ciency are not affected by the different frequency. In other words, the same type of fan can be used without further ado on various networks world­wide. The choice of the right fan for the appli­ca­tion concerned is made easier by an offi­cially certi­fied selec­tion program which is avail­able either as a stand-alone soft­ware package or as a DLL module for inte­gra­tion in the user’s specific equip­ment config­u­ra­tion programs. This can also be used to calcu­late the life cycle costs for the fan concerned. The user thus knows from the very begin­ning what savings poten­tial the new Plug Fans can offer him in prac­tical use.

ModBus inter­face for a simple connec­tion to the control tech­nology

Prac­tical control options are a matter of course with the modern fans. The elec­tronics inte­grated in the drives are not only ideally matched to the EC motors used, they can also be controlled with either a 0 … 10V analogue signal or digi­tally with a ModBus inter­face (greater than 500 W). This makes the connec­tion to the higher order building control system straight­for­ward and prac­tical. Bus networking has impor­tant advan­tages, espe­cially if more than one fan is in use: Starting from config­u­ra­tion during commis­sioning right through to service, fault diag­nosis and main­te­nance, working with the tech­nical fittings is made substan­tially easier if the fans can be accessed from a central PC. Apart from the neces­sary PC soft­ware, there is now a smart­phone-compat­ible version avail­able that can be used to remotely (i.e. without cable connec­tion) program, monitor and control the networked fans via a Blue­tooth inter­face.

For maximum air perfor­mance

Save space by using EC fans (top), as opposed to systems with AC fan and belt drive (bottom)

For greater air perfor­mance, e.g. in centralised air-condi­tioning units or for cooling IT centres, it is no problem to wire several fans in parallel. Detailed measure­ments have shown that instal­la­tion from a distance of about half the impeller diam­eter between the fans has no signif­i­cant influ­ence with respect to reducing the air volume and noise behavior.
Such combi­na­tions not only increase the air perfor­mance but also oper­ating reli­a­bility. Should one of the fans fail, the remaining fans will compen­sate for the lacking air volume. In addi­tion, smaller and lighter fans are vastly easier to install and remove than a large unit. However, this service case is unlikely to occur in prac­tical use. Plug Fans are consid­ered to be extremely reli­able and depend­able. To keep the bearing load on the motors low and to sustain­ably with­stand the high circum­fer­en­tial speeds, the impellers and their seven back­ward curved blades are made completely out of aluminium. The mate­rial is bene­fi­cial for the weight of the fans and at the same time offers a high measure of stability. The indi­vidual blades are welded with a contin­uous seam, which also bene­fits stability and service life. The fans are designed for a service life of more than 40,000 oper­ating hours. That corre­sponds to a contin­uous oper­a­tion of more than 4.5 years, oper­ating under full load and at the maximum permitted ambient temper­a­ture. In partial-load oper­a­tion or at low ambient temper­a­tures, the service life is substan­tially longer. This Plug Fan series with Green­Tech EC tech­nology gives the user durable, highly effi­cient, easy-to-control and high-perfor­mance fans for many different appli­ca­tions in venti­la­tion and air-condi­tioning tech­nology.

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  • Proplas on said:

    Thanks for this article, was an inter­esting read, the devel­op­ments are certainly inter­esting!