Yunca Holdings Ltd

Yunca’s Aluminium Smelter work over the past 20 years totals over 1,000,000 hours, with an estimated 200,000 hours spent in situ

Current work for smelters includes the refurbishment of rod bars and stubs, transition joint replacement, and the supply of cell hoods. In the past 24 months, Yunca redesigned and lightweighted the traditional cell hoods used in smelters for the NZAS and Dubal smelters. Coupled with offering three different insulating solutions, Yunca now have the contract to supply 12,000 cell hoods over the next four years.

Yunca are currently supplying 2,500 cathode bars per annum to smelters, complete with machined ends and copper inserts to a depth of 1500 mm, pressed to 100 tonnes.

Consultancy work completed for smelters includes:

  • Research and development on cathode bar performance and improvement (since the 1990’s).
  • Drafting a complete procedure for the repair/replacement of rod to yoke weld with the view to achieving a zero failure rate (Boyne and NZAS). 
  • Developing modifications to carriers to increase longevity of operating times between service checks.
  • Development of the light weight cell hood.
  • Development and designing of an aluminium slitting machine to supply bus in 6m lengths x 394 mm deep x 151 mm thickness, within tolerances of +/- 1 mm.


Yunca was founded on the principle of quality first, and the company has been driven by Founder Terry Young’s belief that to remain competitive, the company would need constant innovation. 

In the heating sector, Yunca expanded into export markets as far a field as USA and Canada, Europe, Asia and the Middle East, and now manufacture for these export markets from their own plant in Goa, India. 

Yunca operated its own heavy engineering division until 2008, and manufactured transport trailers for a number of New Zealand’s major transport companies including; Mainfreight, HWR Group, WD King and Toll, as well as manufacturing roll cages for the heavy machinery companies Cat, Volvo, Hitachi, Komatsu and Sumitomo.

From 2002, Yunca manufactured components for the Fisher & Paykel Appliance Company from its Dunedin factory, including the manufacture of dish drawers at a production rate of 30,000 per month, until Fisher & Paykel relocated their manufacturing overseas in 2007.  

In 2002, Yunca also established and operated a gas distribution company with Shell Petroleum. The business was sold to Todd Energy in 2010.

Yunca’s Dunedin based Procote Industries enamel finishing factory has been operating since 1982. As well as finishing Yunca’s domestic home heaters; Procote Industries produces finished products for a number of other manufacturers, and for a decade finished all of Fisher & Paykel’s Gas Hobs. 

Research and Development

The desire to keep innovating has led Yunca to invest their design, engineering and  manufacturing capabilities into helping bring new technologies that have an engineering component to market.

Notable projects include Yunca working alongside two of New Zealand’s pre-eminent research institutes, to help interpret the research science and develop engineering solutions for the commercialisation of two quite different developing technologies; the EnPot heat exchanger technology for use in aluminium smelters, and the Hydrogen Califont heating system. 

Hydrogen Califont Heating System

The science behind the Hydrogen Califont heating system has been developed by Callaghan Innovation and involves using photovoltaic electricity generated from solar panels, to separate and capture hydrogen from cold water. The stored hydrogen is then used for water heating.

Yunca were approached by Callaghan Innovation to develop the water heating system for this project. Hydrogen is a notoriously difficult product to use in water heating systems. Yunca decided to take a commercially practical approach and build a prototype conversion kit to convert existing Bosch water heaters from natural gas to Hydrogen, rather than develop a bespoke unit. 

Yunca has been awarded the manufacturing, distribution and marketing rights for the Hydrogen Califont water heating system, and hope to form a joint venture partnership with Esime and Co. Esime have been awarded the marketing rights to the hydrogen electroliser, for their part in developing the system of separating the hydrogen from water. 

Trials are currently underway with an anticipated commercial launch in 2018. 

EnPot Heat Exchanger Technology

In 2009 Yunca were approached by the Light Metals Research Centre (LMRC) of The University of Auckland to help with development of the LMRC Heat Exchanger technology for application inside aluminium smelters.

In particular, Yunca were asked to design the clamping/mounting system to quickly and easily mount the exchangers onto the pot shells, design a balanced duct and extraction fan system, and design the exchanger mechanism that could be produced by pressing in a single step.

In close association with the LMRC the two parties successfully developed the EnPot Heat Exchanger technology to the point it was successfully installed on 12 pots in a smelter in Germany in 2014. The EnPot heat exchanger technology is now ready for commercialisation.


Callaghan Innovation have been working with Yunca for a few years now on the Hydrogen Califont heating system, and have been impressed with how they have interpreted the science and come up with solutions for the water heating system.

While we are a little way off a commercial product, to date things are looking good. We have a great deal of confidence in Yunca’s forward thinking and background expertise when it comes to energy conversion and thermal systems.

— A I Gardiner, Research Engineer, Callaghan Innovation