Until a few years ago, AC asyn­chro­nous and shaded-pole motors were usually used as stan­dard for fan drives in refrig­er­a­tion tech­nology. There were good reasons for this: Both are cheap to produce, robust and durable. However, their low effi­ciency levels of only 30% are no longer accept­able today. Their current consump­tion is high and they also generate waste heat that has to be dissi­pated. And so the use of AC motors is now restricted to just a few niche appli­ca­tions.

Simple replace­ment for greater effi­ciency in refrig­er­ated cabi­nets

Given the energy savings that can be achieved, it is even well worth converting older refrig­er­ated cabi­nets and display cases. In addi­tion to the energy-saving fans already estab­lished on the market with Green­Tech EC tech­nology for refrig­er­a­tion tech­nology, one of the solu­tions ebm-papst has devel­oped is the iQ-one EC motor (Fig. 1), which enables easy one-for-one replace­ment of existing Q or shaded-pole motors with an output power of up to 5 watts. Compared to conven­tional Q motors, it oper­ates with a signif­i­cantly higher effi­ciency of up to 50% and is extremely quiet, even at full power. With its wide voltage input of 100-240 VAC, it can be used world­wide.

The iQ-one can be combined with different fan impellers in sizes 154, 172 and 200 mm. The aero­dy­nam­i­cally opti­mized plastic impellers in sizes 172 and 200 mm in partic­ular creates an effi­cient fan solu­tion for many appli­ca­tions. As stan­dard, the new motor meets the Euro­pean stan­dards EN 60335-2-24 (House­hold appli­ance stan­dard – Partic­ular require­ments for refrig­er­ating appli­ances, ice-cream appli­ances and ice makers) and EN 60335-2-89 (House­hold appli­ance stan­dard – Partic­ular require­ments for commer­cial refrig­er­ating appli­ances and ice-makers) and is there­fore suit­able for today’s natural and flam­mable refrig­er­ants.

Energy effi­ciency in refrig­er­ated display cases

Even more energy can be saved in refrig­er­ated display cases with EC motors from the ESM series. They operate at effi­ciency levels of over 70% at just 10 % of the power consump­tion of compa­rable shaded-pole motors and offer demand-based speed control and networking options. The compact EC motors are avail­able as a complete plug-and-play system with fan impeller and fan housing, with the indi­vidual compo­nents perfectly coor­di­nated with one another. Exam­ples include the energy-saving fans W1G 200 and K1G 200.

The W1G axial product range is intended for instal­la­tion in refrig­er­ated display cases below the lowest display. By contrast, the K1G product range with diag­onal compact fan impeller was specially designed for the rear wall of refrig­er­ated display cases, where there is often limited instal­la­tion space (Fig. 2). Thanks to their very flat design, these fans fit in confined spaces and the diag­onal compact fan design makes them well equipped to deal with the higher back pres­sure encoun­tered in such situ­a­tions.

Robust and ATEX-certi­fied

The AxiACi series offers a wide range of appli­ca­tions for compact areas. AxiACi 92 and AxiACi 120 are used in commer­cial refrig­er­ated cabi­nets in partic­ular, e.g. in service coun­ters in super­mar­kets (Fig. 3). The two EC axial fans are now demon­strating their high flex­i­bility and effi­ciency in switch cabinet cooling appli­ca­tions, as well as in industry and telecom­mu­ni­ca­tions. Refrig­er­ated cabinet manu­fac­turers benefit from their poten­tial oper­ating temper­a­tures down to -40°C (including when starting up), DIN EN 60335-2-89 approval, ATEX certi­fi­ca­tion (DIN EN 60079-7 (Group 2A, T4)), and resis­tance to salt spray, water jets or dust (IP65).

The EC motor, elec­tronics and aero­dy­namic compo­nents are perfectly co-ordi­nated and have a much lower power consump­tion than compa­rable AC fans at the same air flow; in size 92, for example, it is up to 83% lower. Thanks to their low energy consump­tion, it usually pays for itself after months rather than years, and even earlier while elec­tricity prices are rising. The compact fans are also extremely quiet and are suit­able for inter­na­tional use thanks to their broad voltage input.

Less ice forma­tion in cold stores

Today, fans with AC motors are still often used in super­market cold stores. The solu­tion is cost-effec­tive and usually does not require any speed control. However, the poor effi­ciency levels are notice­able in the energy costs and waste heat must also be dissi­pated.

This is why EC fans are worth it here too. There­fore, AxiEco fans can be a good alter­na­tive for cold stores like this. Both AxiEco fans with EC tech­nology, avail­able in the two vari­ants AxiEco Protect and AxiEco Perform (Fig. 4), offer a high level of pres­sure stability at the same time as a high effi­ciency. The air perfor­mance curve has a much steeper slope than with compa­rable axial fans. There­fore, the fans operate at a high effi­ciency even with increasing back pres­sure (Fig. 5).

With many prac­tical design details, the AxiEco Protect series with guard grill has been opti­mized for venti­lation, refrig­er­a­tion and air condi­tioning appli­ca­tions. Evap­o­ra­tors simplify service work and compli­ance with hygiene regu­la­tions, for example. The new flow profile without return flow means that the guard grill does not ice up so quickly.

Drainage chan­nels on the fan blades ensure that, after routine defrosting, melt water can easily drain towards the drip pan provided at the evap­o­rator. This prevents the fan blades from freezing up. At the same time, water is prevented from splashing when the fan is restarted. The more strin­gent the hygiene require­ments, the more impor­tant this feature becomes.

By contrast, the AxiEco Perform fan with housing is recom­mended when a ready-to-install fan is required. As a compact plug and play solu­tion with CE marking, the fans are partic­u­larly easy to inte­grate into appli­ca­tions. Users will not have to worry about nozzles or distance from the impeller, nor concern them­selves with conducting their own ErP assess­ment.

The fan also features an aero­dy­nam­i­cally opti­mized housing with inte­grated guard grill and guide blades. Cavi­ties in the housing corners improve the flow; the guide blades ensure that the swirl in the outlet of the fan, and thus the dynamic losses, are reduced to a minimum. The air throw is also greater than conven­tional axial fans. This enables an even distri­b­u­tion of cold air in large refrig­er­ated ware­houses for example, often meaning that fewer fans are required. There­fore, large cold storage facil­i­ties and halls are typical areas where the energy-effi­cient AxiEco Perform fans are used (Fig. 6).

Digi­tal­iza­tion in cold storage facil­i­ties

In addi­tion to the lowest possible energy consump­tion, reli­a­bility is also an impor­tant topic in cold storage facil­i­ties. If a fan fails, it is impor­tant to localize and rectify the fault quickly without any adverse effect on the cooling chain and before any food perishes. Preven­tive main­te­nance and fan moni­toring are also useful. Here, it helps to network the fans with the ebm-papst Intel­li­Gate gate­ways via the inte­grated serial MODBUS RTU inter­face. This enables numerous moni­toring and control func­tions to be executed in real time via remote moni­toring from the epCloud (Fig. 7).

By eval­u­ating the internal motor data, valu­able infor­ma­tion can be provided about predic­tive and preven­tive main­te­nance measures, and the motor concerned can also be easily local­ized if a service is required. Networking via the commu­ni­ca­tion bus enables fast adap­ta­tion to changing oper­ating condi­tions. After defrosting cycles or if larger quan­ti­ties can be stored, in combi­na­tion with external sensors or data from the building control system, the required cooling temper­a­ture can be reached more quickly by increasing the fan speed. This demand-based closed-loop control opens up further energy-saving poten­tial.