Man has known from the ancient times, how to preserve the produce harvested in the season, for usage year-round. This was primarily done by storing under-ground and ensuring zero exposure of sunlight or air to the harvested products. The art of preserving dairy products flourished in the colder countries, using snow, which came from the sky through the winter months. Man also learnt to keep snow for longer period by letting it freeze to ice, then wrapping ice in bags made of jute, saw-dust, straw and rise husk.
Then came the ice faminein 1890’s when it did not snow all through the winter. It was apparently a prelude to the global warming that we are experiencing today. The demand of ice for South American consumers, enjoying ice from North America & Canada, had to be met. Therefore, search for Mechanical Refrigeration began.
European scientists had already developed scientific method of vapour compression to convert water into ice. Their laboratory experiments were exploited for commercial usage by American entrepreneurs for shipping ice to South America. It is interesting to note that the unit of refrigeration was defined as follows:
“1 ton of refrigeration (1 TR) = amount of cooling required to maintain 1 ton (American ton of 2000 LBS) of ice as ice in its 24 hour journey to South America. The latent heat of fusion of ice is 144 British Thermal Units (BTU) per LB of ice. Thus, 1 TR = (2000 LBS of ice x 144 BTU/LB) ÷ 24 hrs = 12,000 BTU/hr”. The unit is used even today, for rating the cooling capacity of air-conditioning equipment.
Man made ice was thus introduced for the first time in the late 1890’s. This led to domestic refrigerators for the super-rich. You can imagine a party being held in the luxurious home of a Rockefeller or a Kennedy, where the domestic refrigerator was given the pride of place in the centre of the living room, for dispensing ice and ice-creams. The problem was that refrigerants used were highly toxic, namely – Ammonia, Sulphur Dioxide, Nitrous Oxide and others. If the refrigerator was detected to have a leak, the party had to be called off, or moved outdoors, losing its sheen. The first ever refrigerator can still be seen at the Smithsonian Museum along with Wright’s Kitty Hawk, which allowed man to fly.
The major breakthrough for the refrigerants came in 1930s when four young Norwegians, with their fresh PhDs in Chemical Engineering, were assigned, by General Motors and DuPont to develop a non-toxic refrigerant. A long wish list was given to them for the desired properties of the refrigerant.
It is simply incredible that what had eluded man for decades, got zeroed-in by these four young brilliant engineers within a few weeks. They chose four elements out of the entire list of elements; namely – chlorine, fluorine, hydrogen and carbon, for the formulation of the ideal refrigerant. Thus, in the early 30’s dichloro-difluoro-methane came into existence. It fulfilled almost the entire wish-list that was given to the scientists. Thirties were the years of the great depression in America, and the second larger batch being tried on guinea-pigs & rats failed due to spurious chlorine being used. Unfortunately for human history, the spurious chlorine got detected and isolated. Thus, first CFC was proclaimed for use in refrigeration, changing the entire face of refrigeration industry, superseding all natural refrigerants.
Within a few years, the World War II came, and it was discovered that CFC could be effectively used in aerosol bombs. Therefore, the warring countries got busy, through the early 1940’s, shelling cities across Europe, using bombs filled with CFCs. Only when the war ended, the CFCs went back to the refrigeration industry.
The 50s & 60s saw excessive use of CFCs as Panacea for all human wants – like spray can for perfumes, spray cans for toiletries like shaving foam, inflating of leaking automobile tyres, coating of cooking utensils, and for a whole host of consumable durables.
First warning sign of the environmental damage by CFCs came in the early 1970’s when scientists discovered a huge hole in Ozone layer in the outer parts of the earth’s atmosphere. This had resulted into excessive skin cancer amongst the most affluent society in the western part of the USA. Alarm bells were sounded and the culprit was diagnosed to be the chlorine in the CFC. The damage to the Ozone layer was permitting the severely damaging ultraviolet rays of the Sun, to travel unchecked to the occupants on the planet.
The late 80’s & early 90’s saw the plans for phasing out of CFCs in the developed countries. Montreal Protocol was signed, where India was also as a signatory. Sadly, it permitted the developing countries to phase out the CFCs by the middle of this century. The largest population of the planet was thus permitted to use CFCs for a long time. India, China and other developing countries took upon themselves to phase out the CFCs, and align with the countries willing to provide alternate refrigerants, at affordable prices.
It is heartening that countries in Europe and Japan are developing various refrigerants with low or no Ozone Depletion Potential (ODP) and low or no Global Warming Potential (GWP). These refrigerants are eliminating the CFCs, HCFCs and HFCs from European and Japanese markets. Some of these are now being manufactured in India, and we hope the refrigeration industry will soon adopt refrigerants with zero ODP and low GWP, which are becoming commercially viable.
Europe is also moving in a brisk way with the revival of natural refrigerants like Ammonia, with necessary safeties built-in to avoid exposure of humans to the toxic elements of these natural refrigerants.
National Building Code of India has released Addendum I to NBC 2005, titled ‘Approach to Sustainability.’ It contains a Chapter, exclusively dedicated to refrigerants. This will now become part of the Chapter 11 of the new NBC 2015, scheduled to be released early next year. More information can be obtained from the Bureau of Indian Standards (website: www.bis.org.in).
The Indian Society of Heating Refrigerating & Air-conditioning Engineers (ISHRAE) has recently published ‘ISHRAE Position Document on Refrigerants,’ dated December 2015. It is a scholarly compilation, exhorting Indian HVAC&R Industry to keep pace with the rapidly changing scenario in the field of refrigerants. More information can be obtained from ISHRAE Headquarters, by writing to info@ishraehq.in.
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