DUBAI, UAE, 15 September 2019: The latest edition of Eurovent Middle East’s series of ‘HVACR Leadership Workshops’, on September 11 in Dubai, saw a discussion on issues related to variable speed drives. A cross-section of industry experts from the Association’s member companies helmed the discussions.
Jesper Therbo-Pedersen, Global Head of HVACR, Danfoss Drives (Denmark), kicked off the workshop by discussing the importance of taking into consideration energy efficiency across all parts of the HVAC system, and providing technical details aimed at promoting specification of highly efficient drive and motor systems that meet IEC/EN 61800-9-2 and class IE2 standards. “It’s not only about the motor, it’s also about the driven equipment,” he said, touching on the importance of specifying high-quality fans, pumps and compressors to ensure total efficiency of the system. Therbo-Pedersen went on to discuss heat loss, pointing out that even a 2-4% loss leads to significant heat generation. However, he stressed that there are intelligent ways to remove heat and that a number of drive suppliers offer backchannel cooling, which is a smart and economical way of removing heat loss. He also touched on mitigation of harmonics, and the importance of applying IEEE 519-recommended limits to only the PCC and not to individual pieces of equipment.
Utpal Joshi, VRV Consulting Sales, Daikin Middle East and Africa, elaborated on how inverter technology improves the energy efficiency of air conditioning systems and the value of seasonal efficiency in the Middle East. Inverters, he said, can greatly contribute to efforts to mitigate the contribution of cooling to global warming, but that issues surrounding refrigerants, evaporator and condenser efficiency, compressor technology, as well as installation must be addressed. After outlining operational benefits of inverter technology, Joshi stressed that currently there are no regulatory frameworks incentivising adoption of inverter systems and that current labelling mechanisms do not represent the value that inverter-based equipment can offer end users and its value compared to non-inverters, adding that in the Middle East only four per cent of equipment installed is based on inverter technology, compared to almost 100% in Japan.
Deepak Bhat, Manager, Large Tonnage Chillers Sales (GCC), Johnson Controls, highlighted the advantages of Variable Speed Drives in improving performance of medium-voltage centrifugal chillers. “Centrifugal chillers account for 60% of the building’s consumption, he said. “If you are a typical District Cooling plant, you are looking at large motors sitting there consuming continuous power, running at full load. The only way to optimise is to make sure they operate at the right speed.” Currently, he said, variable speed drives are not common in medium and large equipment – a trend, he added, is about to change. One misconception he discussed is that MV VSDs are expensive with unattractive payback; however he countered that the cost and size of MV VSDs have reduced with improved technology and, hence, it is time to reevaluate these misconceptions. He also discussed that contrary to the belief that District Cooling plants operate at full-load conditions, the plants seldom see full Delta Temperature, and as such, chillers are loaded between 60 and 80%.
Providing an IEQ angle, John Fernandez, Managing Director, ebm-papst Middle East, shared insights on advantages using fan arrays, and presented case studies of successful international reference projects. Fernandez explained that fan arrays serve as an alternative fan concept for AHUs, where the building itself serves as the air-handling unit by taking the end wall and populating it with fans. Originating in the US to address needs of data centres, he said that fan array projects are growing fast in the Middle East for new buildings as well as for retrofits. Advantages, he said, includes high air flow, reduced equipment footprint, improved air distribution, lower power consumption, lower cost and in-built redundancy. Fernandez also discussed common questions related to design of fans to ensure maximum performance.
Matteo Zanesco, Managing Director, CAREL Middle East, discussed variable speed drives in the context of cold chain. In addition to benefits related to energy savings, Zanesco highlighted that integrating such technologies also results in better comfort and food preservation, especially in combination with other components, such as electric expansion valves and advanced control algorithms. “It’s not just about temperature but also humidity, which is often more relevant in terms of effect on food preservation,” he said. Such technology, he added, also serves as an environmentally friendly solution that can be readily used for natural refrigerants and can have low noise levels in most applications. Finally, he said the quantity of data available from the system can be leveraged to eliminate food waste and increase system reliability, leading to lower operational cost.
Frank Taaning Grundholm, Vice President, Global HVACR Sales – Drives, ABB Denmark, ended the workshop by looking at the applications of digitalisation within the HVACR sector and opportunities it offers the entire value chain. Grundholm highlight the importance of making innovative and disruptive technologies relevant to the industry by aligning them with efforts to increase efficiency through predictive maintenance, condition monitoring, data sharing and using algorithms “to do more, and do it better”. Grundholm said efficiency can be attained through a continuous cycle of analysing the data, and acting on it. “It’s not always you need more data,” he said. “You need a structured way of looking into it.” Digitalisation, he emphasised can also deliver value through product lifetime by avoiding equipment deterioration, reducing downtime and improving overall productivity.
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Hannah Jo Uy is Assistant Editor at Climate Control Middle East magazine. She may be contacted at firstname.lastname@example.org