Refrigeration compressors were very important in the development of Australia's food industry as they enabled the storage and export of perishable goods. Made in Sydney by C A MacDonald in Ultimo between 1894 and 1909, this compressor was used to train generations of mechanical engineering students at Sydney Technical College to manufacture and maintain ammonia compressors. These still sit at the heart of many refrigeration systems due to the high efficiency of ammonia as a refrigerant and its zero climate and ozone impacts. It does not react with iron, and any small leaks are easily detected by smell. However, ammonia's toxicity and flammability led researchers to develop chemically inert chlorofluorocarbon refrigerants, which were withdrawn decades later after they were shown to damage the Earth's ozone layer.
In 1802 British chemist, John Dalton, founder of modern atomic theory, stated that all gases should turn into liquids when compressed. To test this hypothesis, in 1823 Michael Faraday experimented with a range of gases and noted that ice formed on the outside of the test tube that contained liquid ammonia. In 1856 James Harrison of Geelong, Victoria, patented a cyclic refrigeration system that made use of this effect by alternately compressing diethyl ether gas and allowing it to expand through pipes set in water, forming useful quantities of ice as the ether absorbed heat from its surroundings. Faraday and other scientists took an interest in experiments that Harrison carried out in London, where he had two machines made.
Harrison's Melbourne ice works went into production in 1859, and the Sydney works in 1860. While Australia had imported natural ice from the USA sporadically since 1839, the local works provided a cheaper, more reliable supply, and ice imports ceased in 1876. Although Harrison failed in a bold venture to export frozen meat, he is remembered as the first person to make ice on an industrial scale and as patentee of a system that recycled the refrigerant. One of his patents covered the use of ammonia instead of ether.
The first mechanical refrigeration compressor that enjoyed prolonged success was the Haslam cold air machine (in the Museum's collection object H10484), which was introduced in 1880 based on its inventor's experience with one of Harrison's machines. Installed on ships, the Haslam machines helped establish international trade in unsalted meat, butter, fruit and other perishable produce. Air is such an inefficient but safe refrigerant that it is only used today to air-condition aircraft cabins.
Several manufacturers developed more efficient vapour compression machines in the 1880s and 1890s, using ether, sulphur dioxide, carbon dioxide or ammonia as the refrigerant. The Hercules compressor, and two made in Sydney by James Budge (in the Museum's collection objects 94/76/1 and 94/76/2), are rare survivors from that early phase of the refrigeration industry. Further reflecting the importance of refrigeration in Australian life, the Museum's collection includes a range of domestic evaporative coolers, ice chests, and compression and absorption cycle fridges.
Charles MacDonald as consultant to Hudson Bros 1894: http://nla.gov.au/nla.news-article97527783
Fire at MacDonald's foundry, 1904: http://nla.gov.au/nla.news-article14619239
Formation of Hydraulic Engineering and Hercules Ltd, 1911: http://nla.gov.au/nla.news-article221525183
Debbie Rudder, 2018