Industry We Service
Minus40 serves the entire refrigeration industry, from small commercial through to large industrial facilities, and has significant experience in each individual sector. However, each sector has a different set of needs and constraints, which we have made it our job to understand and address.
Meat and Poultry Production and Processing
All meat production and processing depends heavily on refrigeration for carcass chilling, refrigeration of processing areas, plate and blast freezing of meat and by-products and associate cold storage. Increasingly, heat recovery systems that can have a major benefit on the cost of heating water by using waste heat from refrigeration systems are being used. Most large meat processors use ammonia based refrigeration plants, but some smaller processers still use synthetic refrigerants based systems, in spite of higher operating costs. The intense utilisation of refrigeration plants for meat applications, and the very high proportion of site electric energy used for refrigeration (60-80%) generally makes energy efficiency a viable aspect of plant design in this sector.
Food production can involve a very wide variety of processes and equipment, with requirements for heating, cooling and refrigeration. Products are cooked, chilled, blanched and frozen using a wide variety of processing equipment and stored under chilled or freezer conditions. Refrigeration can be direct (via plate freezers or heat exchangers), indirect (via chilled-water or chilled glycol circulated through jackets or heat exchangers) or via air (chiller or freezer rooms, blast freezers) and scope and scale vary tremendously across the industry and vary widely according to the rate of production, the type of process and ambient temperature. Refrigeration plants therefore vary widely across the industry, with central ammonia or synthetic refrigerant plants, fluid chillers, heat pumps and more. Many applications involve process cooling and heating (with cooling water, chilled water, hot water and steam) in addition to classic refrigeration, and as such the challenges presented within the food manufacturing industry are boundless. As in the case of the meat/poultry processing industry, the intense utilisation of refrigerant plants for food manufacturing applications, and the relatively high proportion of site electric energy used for refrigeration (30-70%) generally makes energy efficiency a viable aspect of plant design in this sector.
Wine and Beverage Industry
Wine production requires careful control of temperature during fermentation and during cold treatment, requiring vast and generally seasonal provision of refrigeration. Most applications use indirect glycol-based cooling systems, with ammonia plant or synthetic refrigerant based chillers commonly used. One of the unique aspects of wine refrigeration is the very low utilisation rates for such refrigeration plants, making it difficult to justify the expense of high-quality or high efficiency refrigeration systems.
The beer and cider industries face similar challenges, but without the distinct seasonal element. The higher utilisation of refrigeration in these industries improves the business case for various energy efficiency and heat recovery projects. The carbonated drinks industry does not have to deal with fermentation, but requires refrigeration to cool warm, sugared solutions prior to carbonation, either by way of direct refrigerant/fluid heat exchangers, or with chilled glycol systems.
Dairy Manufacturing and Processing
The handling and processing of milk and subsequent dairy products requires refrigeration at many steps along the process. From initial vat cooling at the dairy farm, through to further cooling of milk on receival at the dairy, recooling during pasteurisation processes, jacket cooling on holding tanks and room cooling in processing and storage areas, refrigeration is required in many forms. Subsequent processing, especially the manufacture of ice-cream, requires substantial low temperature refrigeration for the various ice-cream churns, paddle-pop freezers and frozen storage. Most larger modern dairies therefore have large central plants, generally ammonia based to provide the required duty. Although slightly seasonal the refrigerant plants for dairy applications is generally well utilised, and the high proportion of site electric energy used for refrigeration (40-60%) generally makes energy efficiency a viable aspect of plant design in this sector.
A unique aspect of Australian dairies is their longevity, and many dairies still have operating refrigeration compressors more than 40 years old. Whilst this proves the value of investing in quality and energy efficiency, care must be taken to ensure that dairy refrigeration systems are modernised to make best use of technological advances and gains in energy efficiency and reliability.
Cold Storage and Distribution
The storage and distribution of chilled and frozen product requires extensive and varied application of refrigeration to ensure that the cold chain requirements are met every step of the way. Transporting product, either by way of refrigerated vehicles or reefer containers, is required to ensure that product arriving at the other end, either the retailer or the cold storage facility, is within the required range of temperatures to ensure quality and shelf life.
Cold storage facility design varies significantly by application and scale. Long term storage leads to large and high storage rooms with deep racking, whilst short-term storage especially for picking services requires easier access to product. Most large scale facilities today are served by large central ammonia plants, either single or two-stage, whilst smaller facilities, especially inner-city food-service or distribution sites, traditionally are served by a variety of synthetic-refrigeration based systems. The increasing viability of using ammonia even for small scale storage is leading to substantial gains in energy efficiency across the industry.
The controlled atmosphere fruit storage industry represents a unique subset of the cold storage industry, in that these storage facilities operate very seasonally. The store fruit from the time of picking around February – April through to final distribution in November -January. During the initial product loading periods, the refrigeration plants operate at high loads to remove the field heat, but use substantially less power for the remainder of the year, reducing further as rooms are progressively emptied.
Generally, refrigeration represents by far the highest contributor to the energy costs for cold storage, generally in the range of 80-90% of site energy use, and as such it pays for cold storage operators to pay attention to energy consumption and the use of high efficiency refrigeration plants.
Many non-food related manufacturing processes require cooling and refrigeration as an integral part of the process. For example, the entire plastics extrusion industry is reliant on process cooling, generally by way of chilled water, to keep the injection dies at a sufficiently low temperature to ensure that the injected materials harden quickly. Similarly, plastic film and metal printing industries require intense cooling by way of chilled or cooling water to function at design production rates, especially at the high Australian ambient conditions. However, great variances in the design of the chilled water systems used, as well as significant differences in the design, performance and energy efficiency of commercially available package chillers means that some production sites are consuming vastly more electrical energy for their process cooling than is required.
Ice making, Storage and Distribution
Ice making, be it tube, flake or cube ice, is one of the oldest applications of mechanical refrigeration, dating back to the time when domestic refrigeration was achieved by purchasing large blocks of ice that were then fitted to ice-boxes or coolrooms. In fact, the very first ever compression refrigeration system served an ice-plant in Geelong, Victoria! Today the scale of ice-making varies considerably, and many small and packaged flake and cube-ice machines with integrated refrigeration systems are now available as plug-and-play units for the hospitality industry. Tube and also flake ice is generated on industrial scale plants, with larger units generally using ammonia refrigeration plants. Flake ice is generally used in the fish industry, as it is easily handled and shovelled and does not damaged even small fish, whereas tube ice is used mostly for recreational purposes and sold at servos and bottle-stores. As such the latter industry in particular is very seasonal, with peak ice production at Christmas and Easter, with substantial quiet periods during the cooler months. Tube ice making is an interesting process as it is a batch process, with distinct make and harvest cycles. All ice making facilities also require ice handling, storage and bagging facilities, another special field.
Supermarket and Retail Sector
Retail refrigeration, comprising supermarkets, servos, corner stores, deli’s and other food retail outlets represents one of the single largest refrigeration markets in Australia, and one of the largest sectors with commercial refrigeration, and also one that has seen nearly constant change of technology for the past 20-30 years. This sector is dominated by short-lived systems using synthetic refrigerants, and these have seen significant regulation-driven changes in recent years. The phase out of ozone depleting CFC and HCFC refrigerants, the short-lived carbon tax on HFCs, and the upcoming phase-down of the HFCs by 2030 have all caused constant flux and innovation in this sector. Today most new large system use Carbon Dioxide (CO2, R744) as the main refrigerant, augmented by HFC134A or ammonia. HFC404A is still widely used for smaller systems, but small scale CO2 and Hydrocarbon systems are making inroads into this area. The rapid change in this sector is partly caused by the very short useful life of most retail refrigeration systems, generally 10 years or less, resulting in far more frequent replacement of plants than is common in industrial refrigeration, where 25-35 year plant life is common. In addition to the changing refrigerant landscape, service and energy costs are significant drivers for change in this sector.
The hospitality sector, representing pubs, clubs, hotels and restaurants is the other major user of commercial refrigeration technology, alongside retail, and has similarly been beset by the changing refrigerants and other issues. More markedly, the hospitality sector is served by many small operators, and is a highly capital cost driven sector, to the detriment of quality end energy efficiency. This sector is beset with reliability and energy efficiency problems, and the fragmented nature of the industry and small scale of the systems presents particular challenges to achieving quality outcomes in many cases. The increasing availability of tailored finance solutions for small scale energy efficiency projects may open the door to improving the level of engineering and energy efficiency in this sector over time.