As a general rule, the “low hanging fruit” will have been picked long ago. However, industry is constantly on the look-out for other ways to save energy. The enclosure cooling units from the Rittal Blue e+ S range are proof that there is still a fair amount of scope for energy savings. Prior to its market launch, the new development was put through its paces in the in-house production at Diehl Controls, the Wangen-based electronics specialist.
Text Dr. Jörg Lantzsch ––– Photography
For industrial companies, the need to reduce their carbon footprint is increasingly becoming a very real economic necessity. “Energy efficiency is one of our key priorities and an integral part of our strategy. We look for ways to improve energy efficiency in every new system and production line,” explains Stefan Wespel, Value Stream Manager at Diehl Controls.
Based in Wangen im Allgäu in Germany, the company manufactures a range of products, including electronic subassemblies for the domestic appliance industry. Diehl Controls is certainly not the only company looking for solutions to reduce the carbon footprint of its production facility. These solutions need to be both smart and communicative so they can be easily integrated into digitalized manufacturing environments.
One possible way to save energy in manufacturing processes is to use energyefficient enclosure cooling units. “Even if this application may appear to be no more than an ancillary process, there’s often hidden and unexpected potential here,” explains Steffen Wagner, Head of Product Management at Rittal. “To harness this potential, Rittal has been offering its Blue e+ range of cooling units since 2015. These are extremely efficient, resulting in average energy savings of up to 75 per cent.” The manufacturer has now expanded its Blue e+ range and is launching its “Blue e+ S” products – cooling units in smaller output classes of 300, 500, 750 (from 2023) and 1,000 watts – on the market. Now, Diehl Controls has conducted trials at its manufacturing site in Wangen to see whether these “little ones” really can keep up with their bigger siblings in the product family when it comes to energy efficiency.
Stefan Wespel
Value Stream Manager at Diehl Controls
One of the new cooling units has been in place in the manufacturing workshop since summer 2021. The test engineers have fitted an electricity meter to both the new unit and an older one so that power consumption can be recorded over the course of the test period and the figures compared. “During the first six months, the new cooling unit consumed 60 per cent less electricity than the older unit being used for the comparison,” Wespel confirms. Extrapolating this figure to cover an entire year points to energy savings of 140 euros per unit. It’s “a fantastic result”, as the Value Stream Manager puts it. Since the cooling units in these smaller output classes can be used in large numbers, this could result in excellent savings overall.
The reason behind these enormous savings is the Blue e+ technology used – a heat pipe combined with an inverter and speed-controlled components (compressor and fan). “As the heat pipe works without a compressor, expansion valve or other regulating elements, it doesn’t need any electrical energy,” explains Wagner. Depending on the thermal energy in the enclosure that needs to be dissipated and the ambient temperature at the time, cooling can sometimes take place via the heat pipe alone.
It’s only when a large amount of heat needs to be removed from the enclosure or when the ambient temperature is very high that the additional compressor cooling kicks in. This compressor is significantly more energy-efficient than conventional hardware, too. The compressor and fan feature an inverter-controlled drive, meaning speed can be tailored to requirements. As a result, not only is there less cooling hysteresis, but energy efficiency is much better, too. The excellent energy efficiency is only one of the reasons for the smaller carbon footprint, however.
The coolant used for the new Blue e+ S range also has a GWP (Global Warming Potential) that is 56 per cent lower than that of the coolant used in other units. Instead of R‑134A, which has been used up until now, the compressor in the new-generation units uses R‑513A. This is an important aspect if the coolant escapes into the environment due to a leak.
The new cooling units feature additional smart functions that are also useful when it comes to the second factor – digitalization. Thanks to a series-standard integrated interface for direct connectivity to the Smart Service Portal, the cooling units can be intelligently monitored in digitalized environments. When it’s a case of working in networked, complex production environments, a high level of availability is frequently called for. It’s very easy to connect the Blue e+ S cooling units to the new Rittal Smart Service Portal. This optimises the service processes and boosts efficiency thanks to predictive maintenance. Unplanned downtimes that can result in high production costs – especially when it comes to Industry 4.0 processes – are therefore prevented.
Simply smart: It’s very easy to connect the energy-efficient Blue e+ S cooling units to the new Rittal Smart Service Portal.
The cooling units in the smaller output classes have also been redesigned. The most striking design feature is an integrated, coloured LED light strip. This means status messages from the unit can be quickly identified. A display on the front of the enclosure shows other up-to-date information. The cooling units are also equipped with the familiar NFC interface. This means they can communicate with mobile devices that have the Rittal Scan & Service app installed (now also available for iOS/iPhone).
This provides even more scope for efficiency! At first glance, reducing the energy consumption of units with smaller cooling outputs may not appear to be particularly significant in terms of overall efficiency. Since a huge number of these units are used in practice, however, this nevertheless offers a great opportunity to cut total energy consumption and costs considerably.
