Research Scientists Survey the Path towards 4 mm Copper Tube

Figure 1: LU-VE Headquarters

Founded in 1985, LU-VE Group has steadily grown through acquisitions and greenfield expansion in the ensuing decades. The company operates out of headquarters in Uboldo Italy, just outside of Milan, but has important manufacturing capabilities in China, Czech Rep., Finland, India, Poland, Russia & Sweden. It is also now building production capacity in the USA.

Here three spotlights are put on the LU-VE Group: one on its business acumen, another on its manufacturing know-how, and a third spotlight on its research.

Greenfields and Acquisitions

The LU-VE Group has grown steadily over nearly four decades. Figure 2 gives a timeline of acquisitions and mergers as well as greenfield expansions. A recent video describes the size and scope of the company “in numbers.”

Video 1: LU-VE Group in Numbers

Today the LU-VE Group lays claim to being third largest operator in the world and second largest in Europe in the production of air heat exchangers. Its founder Iginio Liberali in a speech recorded at Chilventa 2016 set a goal for the LU-VE Group to reach one billion dollars in sales by its 50^th Anniversary in 2036 (Video 2).

Video 2: Founder Iginio Liberali speech at Chillventa 2016

Since that speech, the LU-VE Group acquired Spirotech, Zyklus, AL Air and Refrion. The LU-VE Group doubled in size since 2016, despite the global pandemic. As an environmentally conscious company with a rich portfolio of patents and technology, the LU-VE Group is ready to continue to expand. The good news is that LU-VE USA is gearing up for expansion in the USA.

LU-VE’s beloved founder Iginio Liberali passed away in December 2022 but his spirit lives on. His son Matteo Liberali was appointed CEO and President by the Board of Directors in 2023. In a press release issued on 8 June 2023, Matteo Liberali, CEO of LU-VE Group said the following:



“We are very proud to advance two more steps in our international expansion plan in strategic geographical areas. China and Southeast Asia are booming markets for us. We have decided to further strengthen the plant, also to enjoy the advantages of ‘For China from China’, the new policy of the Chinese government intended to increase national consumption of high quality products. This also includes the policy of expanding the cold chain, where investments of around €80 billion are planned in the period 2023-2028. The second step is in the USA: we are strengthening our presence in the country to consolidate our positioning and seize the development opportunities that the market offers: for this reason we plan to expand the plant with the aim of expanding our offer and increasing production capacity.”

The company has since made a presentation at ATMO America in June 2023 and exhibited at the AHR Expo in Chicago in 2024.

What is the secret to LU-VE’s success?

Figure 2: Acquisitions and Greenfields

Manufacturing Prowess

One key to the success for the LU-VE Group has been its mastery of the manufacture of evaporators, condensers and gas coolers made from smaller diameter copper tubes. Notable in its early years was the acquisition of SEST S.p.A. Since then LU-VE has emerged as the European market leader in the production of heat exchanger finned coils for the commercial refrigeration and air conditioning sectors. The acquisition of SEST by LU-VE in the early 1990s set LU-VE on a course of expansion, leading to its growth into the LU-VE Group.

SEST Italy is situated in the Dolomite Alps in northeastern Italy in the picturesque commune of Limana. That’s about 70 kilometers north of Venice in the province of Belluno in the Italian region of Veneto.

SEST was founded in 1974 as a supplier to a leading refrigerated counter manufacturer. A video (in Italian) made on the occasion of its 30^th anniversary provides insights into the history and growth of the company through 2004, mirroring the early growth trajectory of the LU-VE, including video of the LU-VE SEST’s expansion into Poland.

Video 3: The Limana plant is a workhorse of the LU-VE Group.

The acquisition of SEST has been instrumental to the continued growth of the LU-VE Group. LU-VE’s first investment in a new “greenfield” facility was for the Polish plant in Gliwice, which was further expanded in 2018. Gliwice is about 17 miles west of Katowici and 60 miles west of Krakow just north of the border between the Czech Republic and Slovakia. Meanwhile, LU-VE also acquired Heat Transfer Systems (HTS), Novosedly, which is in the South Moravian Region of the Czech Republic, bordering on Austria and also near Slovakia.

Since 2019, all operations regarding the coils manufacturing have been reported under the brand LU-VE Coils.

Video 4: Corporate video of Heat Transfer Systems s.r.o.

Spirotech India is another manufacturing powerhouse. The company was spotlighted in the MicroGroove Update in 2013 (Volume 3, Issue 2) and was acquired by LU-VE in 2016. Spirotech Heat Exchangers Inc. was among the first companies to adopt MicroGroove. Based in Bhiwadi, Rajasthan (about 60 km south of New Delhi), the plant makes MicroGroove heat exchangers for heat pumps, air conditioners and refrigeration systems, including MicroGroove heat exchangers for R744 systems. For more about Spirotech, see the video “Presentation and Factory Tour,” October 31, 2018. The video can be accessed from the LU-VE SPIROTECH home page or directly on YouTube.

Video 5: Spirotech Presentation and Factory Tour

Spotlight on Research

Another secret to success is a strong research program. In addition to boasting one of the largest R&D laboratories in its sector in Europe, the Group collaborates with around 30 universities located in 13 countries: in particular, since 1986 it has cooperated on an ongoing basis with the Polytechnic of Milan. Thanks to this strategy, LU-VE has introduced a new way of conceiving and manufacturing refrigeration and air conditioning products, developing cutting-edge technologies that have become a point of reference for the entire sector.

The development of 5 mm copper tube technology can be partly traced through technical papers presented over the years at the quadrennial International Congress of Refrigeration. (See references below.) These papers proved to be prescient. If you are seeking a clear look ahead at the future of heat exchangers, then ICR presentations by LU-VE are a good place to start.

At the 23rd IIR ICR held in Prague in 2011, Stefano Filippini (Group Innovation & Application Research Director) and Umberto Merlo (Head of Thermal Design & CFD and Laboratory) from LU-VE authored a paper titled “Air Cooled Heat Exchangers For CO2 Refrigeration Cycles” in which they described the challenges specific to developing efficient CO2 gas cooler.

Compared to an HFC condenser, these gas coolers typically have working pressures (120 bar) that are almost four times higher; and double the temperature (150 °C). Nonetheless, the authors were confident that “the applications of CO2 in the refrigeration industry could shortly become an important reality.” Furthermore, they concluded that “fin-and-tube geometries used for conventional fluids are perfectly adequate to CO2 application in the case of LU-VE production, which has for many years concentrated on small diameter tubes even for large units. The use of the water spray system helps to significantly improve general efficiency at high ambient temperatures.” Of course, these predictions proved prescient. R744 refrigeration systems have become quite popular in Europe.

At the 25th IIR ICR held in Montreal in 2019, Stefano Filippini gave an update on the gas coolers for R744. By then, LU-VE had already introduced its Minichannel CO2 gas cooler, which benefits from high air-side and refrigerant-side heat transfer coefficients (HTCs), a compact design, less materials usage and less refrigerant charge, using 5 mm diameter copper tubes rather than larger diameter copper tubes.

In its December 2023 ATMOsphere, publisher of R744.com, released the 2023 Edition of its “Natural Refrigerants: State of the Industry” Market Report with data showing robust growth of transcritical CO2 (R744) installations in commercial and industrial applications in North America, Europe and Japan. According to the report, as of December 2023, there were approximately

71,800 transcritical CO2 sites in Europe, including 3,300 industrial sites.

ATMOsphere estimated 3.2 million hydrocarbon-based retail cabinets have been installed in Europe as of December 2023, an increase of 10% from 2022, when there were an estimated 2.9 million.

In the 26th IIR ICR held in Paris in 2023, a groundbreaking, future looking paper was again presented by Stefano Filippini from LU-VE. Coauthors included Umberto Merlo, Dario Demurtas and Federico Volonté from LU-VE as well as professors Luca Molinaroli and Ennio Macchi from Politecnico di Milano. Paper 0340 was modestly titled “Geometry miniaturization in fin-and-tube heat exchangers for refrigerant charge reduction.”

This paper was not specifically on R744 gas coolers. Rather it was on a new heat exchanger geometry for small air-to-water heat pumps.

Experimental Campaign on 4 mm Copper Tubes

LU-VE Group was a pioneer in 5 mm copper tube technology and in R744 gas coolers. Now the company has undertaken a research project to optimize the technology for 4 mm copper tubes. If the past is prelude, then it will be wise to pay attention to this research from LU-VE. The 2023 ICR paper is a model for exacting research and also clear presentation of research results.

The research began with simulations to compare the performance of various configurations of heat exchangers with 4 mm diameter tubes, The objective was to maximize the ratio of Thermal Capacity to the Internal Volume. Obviously the goal is to increase the thermal capacity while reducing the internal volume.

Any and all of the configurations with 4 mm copper tubes rather easily produced an improvement compared to the configuration with 5 mm copper tubes. This is an obvious result, considering the reduction in internal volume and also the improved internal and external heat transfer coefficients. This performance improvement was expressed as a percent increase compared to the 5 mm tube baseline configuration. It ranged from 8 percent to more than 50 percent. The best results were obtained using 4-rows of tubes with a 20 mm x 17.3 mm tube geometry (i.e., with tubes pitch 20 mm and rows pitch 17.3 mm).

To validate the preliminary theoretical studies, an extensive experimental campaign was then carried out, aimed at defining the performance of the fins, the grooved tubes and the exchanger in its entirety. For full details, see the original paper. The experimental campaign is impressive!

In the end, it was found that the adoption of this new geometry for the construction of fin-and-tube evaporators in a small air-to-water heat pump for residential application can thus achieve a refrigerant charge reduction (up to 36 percent) compared to current market solutions.

The LU-VE Group holds numerous patents. The LU-VE Group has invested in research and development since its inception. Its constant commitment to R&D has allowed the company to affirm its technological leadership.

This result bodes well for the development of heat pump technology. It is beyond the scope of this current article to predict what effects 4 mm copper may have on the development of future heat pumps.

References and Links

LU-VE Group: SEST Landing Page

https://components.luvegroup.com/en/il-gruppo/societa-produttive/sest/

Zyklus (News Release)

https://www.coolingpost.com/world-news/lu-ve-renames-zyklus-to-form-lu-ve-us-inc/

LU-VE Group: Alfa, Landing Page

https://alfa.luvegroup.com/

Refrion, Italy, Landing Page

https://www.refrion.com/en/

LU-VE Group: HTS, Czech Republic, Landing Page

https://components.luvegroup.com/en/il-gruppo/societa-produttive/hts/

LU-VE news release: LU-VE Group continues to grow abroad and expands in China and the US (June 6, 2023)

https://www.luvegroup.com/en/news/news/2023/06/22/lu-ve-group-continues-to-grow-abroad-and-expands-in-china-and-the-usa/

Corporate video of HTS - Heat Transfer Systems s.r.o.

https://youtu.be/vo-1_qvi-LE?si=N8z7lFCph12IkNir

LU-VE Group: Spirotech Landing Page

https://components.luvegroup.com/en/il-gruppo/societa-produttive/spirotech/

MicroGroove Update, Vol. 3, Number 3, In the Spotlight: NanoGiant Air-Cooled Condensers From Lu-Ve Group Boast Smaller Diameter Copper Tubes"

https://microgroove.net/sites/default/files/microgroove_nl_update_3.pdf 

MicroGroove Update, Vol. 3, Number 2, "In the Spotlight: SPIROTECH Moves to Smaller-Diameter Copper Tubes"

https://microgroove.net/sites/default/files/6053_microgroove_nl_may-june_2013-final.pdf

ATMOsphere (publisher of R744.com) 2023 Edition of its “Natural Refrigerants: State of the Industry” Market Report.

https://atmosphere.cool/product/natural-refrigerants-state-of-the-industry-2023-edition-free/

Stephano Filippini and Umberto Merlo (2011) “Air Cooled Heat Exchangers for CO2 Refrigeration Cycles,” Proceedings of the 23th IIR International Congress of ‎Refrigeration, Prague, Paper 0295.

Stephano Filippini, Umberto Merlo, Giovanni Mariani et alia (2019) "High efficiency air cooled heat exchangers for CO2 applications"

Proceedings of the 25th IIR International Congress of Refrigeration: Montreal, Canada, August 24-30, 2019. (Paper 326).

Stefano Filippini, Umberto Merlo, Dario Demurtas, Federico Volonté, Luca Molinaroli, Ennio Macchi (2023) “Geometry miniaturization in fin-and-tube heat exchangers for refrigerant charge reduction.” Proceedings of the 26th IIR International Congress of ‎Refrigeration, Paris, Paper 0340.

Acknowledgements

The MicroGroove Update editors would like to thank Livio Perrotta, Product & Marketing Manager for Cooling Systems from the LU-VE Group, for assistance in the preparation of this column.

New White Paper

Frank Gao, Harry Schmitz, Yoram Shabtay, Kerry Song, Appliance & HVAC Report, “HVACR Engineers Focus on Cold-Climate Heat Pumps,” October 2023, Page 22

Appliance & HVAC Report Vol. 5, No. 4 (appliancehvacreport.com)

1023_AHR_ColdClimateHeatPumps_whitepaper.pdf (appliancehvacreport.com)

New Technical Publications

NEW! conference paper by Yoram Shabtay, Peter Mostovoy, Ji Song, Yifeng Gao, “Principles ‎of Evaporator Coil Design for Air Source Cold Climate Heat Pumps Using Smaller Diameter ‎Copper Tubes and Low GWP Refrigerants,” Paper 0191 at International Congress of ‎Refrigeration, Paris (2023).‎

https://microgroove.net/sites/default/files/icr2023-paper-0191-final-aug-1.pdf

https://microgroove.net/sites/default/files/slideshow-icr-2023-oral-presentation_final_1.pdf

Recent and Upcoming Events

2024 ATMOsphere America

June 10-11, 2024

Washington D.C.

https://atmo.org/events/atmosphere-america-summit-2024/

China Refrigeration Expo: The 35th International Exhibition on Refrigeration, Air-conditioning, Heating ‎and Ventilation, Frozen Food Processing, Packaging and Storage

April 8, 2024 - April 10, 2024

Beijing, China

https://www.cr-expo.com/en/index.aspx

Herrick Conferences,

July 15, 2024 - July 18, 2024

Purdue University

West Lafayette, Indiana

https://engineering.purdue.edu/Herrick/about/news/Conferences