Environmentally friendly down under

Wide roads, artificially watered front gardens and a small cricket ground – Prestons is a typical suburb of Sydney and is situated around 37 kilometres to the south-west of Australia’s largest city. In this quiet town, the thermometer climbs up to 45 degrees Celsius in summer. Offering food products which are always fresh and well refrigerated is no easy task in these extreme conditions. Despite this, Woolworths dared to break new ground doing exactly that. On 6 December 2018 in Prestons, the largest supermarket chain on the continent opened its first store with refrigeration, air conditioning and heating, which operates solely with the environmentally friendly refrigerant CO₂ (R744). The complete refrigeration system was designed, manufactured and supplied by BITZER Australia.

VARIPACK and ECOLINE – a perfect partnership

Refrigeration, air conditioning and heating– and all that with one single efficient compound system which uses carbon dioxide as a natural refrigerant. Woolworths worked closely with BITZER for this innovation. They have already been driving innovation in the development and production of compressors for CO₂ applications for almost 25 years. ‘We are pleased that we were able to help Woolworths in reducing greenhouse gas emissions and protecting the environment in the long term. Not only did we provide compressors, but also frequency inverters and control elements,’ says Simon Wood, Managing Director BITZER Australia.

The compound system in Prestons consists of two equal systems with seven BITZER ECOLINE compressors for transcritical CO₂ applications and two BITZER ME subcritical CO₂ compressors. Also included with each system were three external VARIPACK frequency inverters and a fully equipped electrical and control system. The combination of semi-hermetic reciprocating compressors and the latest generation of frequency inverters from BITZER guarantees precise and flexible capacity control. Simon Wood explains: ‘Our VARIPACK frequency inverters work reliably and are quick to commission. With their help, users can make their systems more efficient and thus save both energy and costs.’

Natural refrigerants and supermarkets – BITZER makes it possible!

It’s a solution which suits Woolworths perfectly, as a green and climate-friendly future is a key component in Woolworths’ corporate strategy. In order to achieve this objective, the Australian company has got a lot planned. Apart from recyclable packaging, a zero food waste policy and numerous solar cells on the roofs of their stores, Woolworths is particularly pressing ahead with the changeover from synthetic to natural refrigerants in its supermarkets.

‘We want to extend the use of natural refrigerants across the whole company,’ emphasises Dario Ferlin, Refrigeration & Sustainable Innovations Engineer at Woolworths. ‘In order to reduce our greenhouse gas emissions, we will have installed transcritical CO₂ refrigeration systems in at least ten stores by the end of 2020. We are therefore relying on the innovative solutions by BITZER in Prestons.’

Good in the past, better in future

To date, Woolworths has had R134a/CO₂ cascade systems installed in around 300 of its supermarkets across Australia and New Zealand. However in future the company wants to go even further and completely do away with synthetic refrigerants such as R134a. When it comes to this ambitious goal, Dario Ferlin has found the right man for the job in Simon Wood, Managing Director of BITZER Australia: ‘From planning right up to consultation and the subsequent installation of the system, BITZER Australia was reliably at our side as our local partner. This has the advantage that expertise is locally available – even after the supermarket is opened.’

A future without synthetic refrigerants

BITZER Australia also took care of the design and production of the compressor mounts in Prestons. The refrigeration and air conditioning system is perfectly tailored to requirements at the Prestons store in order to guarantee a reliable cooling chain, even with summer temperatures of over 45 degrees Celsius. The system offers 34 kW refrigerating capacity for low temperature applications, 205 kW for medium temperature applications as well as 325 kW for space cooling and 154 kW for space heating. ‘In this supermarket we have completely done away with synthetic refrigerants. An important step for the future of our company and for environmentally friendly refrigeration technology in Australian supermarkets,’ explains Dario Ferlin.

A successful pilot project

The collaboration between Woolworths and BITZER Australia began in 2017. This was the year in which the Refrigeration and air conditioning specialist supplied several ECOLINE reciprocating compressors for transcritical CO₂ applications. The site was a 3,200-square-metre Woolworths supermarket in Greenway Village in Sydney’s North West. Even after only one year of operation, it was clear to the engineers that using R744 was a complete success – both from a technical and a cost-effectiveness point of view. This is because systems with transcritical CO₂ compressors work up to 15 per cent more efficiently than standard refrigeration systems.

‘The system in Colebee was a pilot project for us. We wanted a reliable, robust and cost-efficient system which proved that efficient and environmentally friendly refrigeration and air conditioning systems in supermarkets are also possible under Australia’s extreme conditions. This knowledge was a great benefit to us in the new store in Prestons. Here we use the CO₂ compressors not only for food refrigeration, but also for the entire air conditioning of the supermarket. This is a solution which we will apply to further applications in future,’ says Simon Wood from BITZER Australia.