INDIAN fridge manufacturers may find an alternative to chlorofluorocarbons (CFC) in a technology that is being revived in some European countries. Besides being eco-friendly, the adoption of this technology will rid Indian manufacturers of dependence on Western companies for a CFC substitute.
Most substitutes on offer today for ozone-depleting CFCs, which are used as coolants in fridges, have either an ozone-depleting potential or a global warming potential or both. Hydrochlorofluorocarbons (HCFCs) are now known to also be ozone depleting and a hydrofluorocarbon -- HFC-134a -- contributes to a different environment problem: global warming.
The Indian industry is keeping its options open on CFC substitutes. Most of them have initiated in-house research and development projects and some are shopping around globally to see what alternatives are available.
Though some manufacturers plan to switch to HFC-134a, others are looking at adapting ozone-friendly technologies to suit Indian conditions. A possible option is the Ecofrig, which uses as a coolant a hydrocarbon mixture that does not endanger the ozone layer and does not contribute to global warming. Some manufacturers are collaborating with the manufacturer of Ecofrig to assess its suitability for Indian conditions.
Indian manufacturers are cautiously watching developments abroad. Says Voltas' divisional manager of research and development R S Iyer, "Today, the Indian industry is interested in all the available options. Our overriding concern is to ensure that we are not forced to change over more than once, as each replacement costs money. So, we are watching technological and policy developments abroad before we commit ourselves to any one coolant."
K V N Rao, vice president of research and development at Kelvinator India, concurs. "The change-over from CFCs to non-CFCs is akin to a revolution for this industry and we cannot rush in to use a particular coolant. All the technological, economic and commercial conditions will change and we have to judge what will be the best for us. Moreover, we are particularly cautious about using a controversial refrigerant and will only make a commitment once the chemical is proven."
The Europeans are not convinced that the alternatives to CFCs currently being touted are the most appropriate. A technology similar to hydrocarbons, which was used before CFCs edged it out about 40 years ago, is being revived and promoted by Greenpeace, the international environmental activist pressure group. A small German company -- FORON -- in cooperation with Greenpeace has developed an energy efficient fridge called Greenfreeze, which uses an extremely purified form of liquified petroleum gas (LPG) as a coolant .
Greenfreeze uses a mixture of propane and isobutane as a refrigerant. This hydrocarbon mixture is being welcomed by several manufacturers who see this as a cheap, readily available alternative that requires only minor modifications in their machinery. Hydrocarbon mixtures cost about half what CFC-12 does and about a tenth of HFC-134a.
But there are some problems with using a hydrocarbon mixture as a refrigerant. Each fluid in the hydrocarbon mixture boils and condenses at different temperatures and this can affect the cooling efficiency of the fridge, say experts. This becomes especially problematic when a freezer compartment is required as a part of the fridge.
The freezer has to be maintained at minus 18oC but the fridge chamber has a temperature of 3-5oC which becomes difficult using these fluids. FORON, too, has not been able to overcome this problem, and its prototype has only a single chamber -- the refrigeration chamber.
The option of hydrocarbons may well be ideal for a country like India. They are both eco-friendly and cheap. And, its limitations can be overcome with research.
Most Indian manufacturers agree the refrigerant's limitations have to be sorted out before they can accept a hydrocarbon mixture as a coolant. As they see it, the main attraction of a fridge to the buyer is the freezer compartment. The average buyer thinks less of the food preservation attributes of a fridge than its ability to produce ice, they say.
Manufacturers also point out that Indian fridges work in conditions that are very different from those in Europe. Indian fridges are expected to produce sufficient quantities of ice when ambient temperatures are as high as 45oC. Moreover, the difference between temperatures inside and outside the refrigerator is often twice what it is in Europe. Also, they contend that because more people use each fridge in India, the number of times its door is opened is also greater, affecting the efficiency of the fridge.
But R S Agarwal, professor of mechanical engineering at the Indian Institute of Technology, Delhi, who also coordinates the Ecofrig project in India, says the hydrocarbon technology is easy to handle, cheap and can be adapted to work in Indian conditions. "Ecofrig's refrigerant is cheap and environmentally friendly. It appears to be a very good option for India," he says.
Another problem is the purity of hydrocarbons used. Though these gases should be available easily in the country, manufacturers are concerned about their purity. Says Rao, "This will be crucial because impurities can block the very fine capillary tubes that carry the gas from the compressor to the condenser and then to the evaporator and back to the compressor, seriously affecting refrigerator performance."
The inflammable nature of the hydrocarbon mixture is also a source of worry for manufacturers, who feel this could make Indian housewives reluctant to use such refrigerators. However, Agarwal and S Devotta, head of engineering services at the National Chemical Laboratory in Pune, feel the manufacturers' fears may well turn out to be unfounded. The quantity of hydrocarbons used is very small, they say. Some 100 to 140 gm of CFC-12 is normally used in a 165-litre refrigerator, but a hydrocarbon fridge requires only 25 to 27 g of the fluid -- equivalent to the capacity of two cigarette lighters. They say it certainly isn't much to get excited about, especially because most housewives store as much as 14.5 kg of highly flammable LPG in their kitchens.
Safe in homes
Officials of the Union ministry of environment and forests(MEF) which has drawn up a schedule for phasing out ozone-depleting substances, feel the hydrocarbons would be safe in homes. Says MEF joint director Indrani Chandrashekharan, "The quantity used will be well below the lowest explosive level and the fluids can be stenched to make them detectable by smell."
What worries the MEF is that these fluids will have to be released and refilled by servicing personnel. Most servicing of refrigerators is now done by mechanics in the unorganised sector and MEF officials fear that accidents due to the flammable nature of these fluids could occur at this time. However, Devotta points out that FORON has developed special refill cylinders that could also be produced in India to overcome this problem.
The West's choice
Western governments project HFC-134a as the best option, but its high global warming potential would mean it would have to be replaced in a decade or so, when global warming becomes a bigger problem than ozone depletion. Besides, technology to manufacture HFC-134a is available with only a handful of multinationals such as DuPont and ICI, which had come out with the CFCs in the first place and now want to earn billions by supplying a technology that may soon become unacceptable.
Manufacturers abroad, especially in the US and Japan, have turned en masse to HFC-134a, and it is a leading contender for replacing CFC-12 in India, too. But unlike CFC-12, which is produced in India in adequate quantities, HFC-134a has to imported. Recently, however, scientists at Hyderabad's Indian Institute of Chemical Technology announced they can produce the chemical in the laboratory .
HFC-134a is an effective coolant that has gained considerable acceptability in the West, says Devotta. In fact, BPL Sanyo plans to produce India's first HFC-134a fridge using technology obtained from its parent company -- Sanyo of Japan -- by 1995.
But Devotta points out that in the Indian context, the coolant has a number of problems that still have to be sorted out. For one, explains Rao, "HFCs are not compatible with the mineral lubricating oils that are used in CFC-12 refrigerators." So the introduction of this gas would require changing the lubricating oil. Though an oil compatible with HFC-134a has been found, manufacturers point out that it is expensive and not available easily.
Moreover, the oils compatible with HFC-134a are hygroscopic -- they tend to absorb water and form an acid that can corrode the insulation of the motor winding wires. This is especially a problem in the tropics, says Agarwal, where the humidity is high. Switching over to HFC-134a will, therefore, also mean redesigning compressor motors and this could prove to be rather expensive, manufacturers say. In addition, personnel servicing HFC-134a refrigerators would have to ensure cleanliness to prevent contamination of the fluid.
There is also a fear that HFC-134a may be put onto the banned list of the Montreal Protocol on Substances that Deplete the Ozone Layer in the future because of its global warming potential, making it only a temporary CFC-12 substitute. And, given the expense of each changeover, caution is necessary, says Iyer.
However, an important point in favour of HFC-134a, say manufacturers, is that it is used in the US and Japan and several other countries are likely to follow suit. This becomes important especially if we plan to export refrigerators, they contend.
Under the Montreal Protocol, to which India became a signatory in 1992, CFCs have to phased out in India and the developing world by 2010 and there are indications this deadline will be advanced by 4 years.
Of all the substances banned by the Montreal Protocol, India currently produces and uses only seven. Of these, CFC-11 is used in insulation and other foams and in central air-conditioning plants, and CFC-12 is used in domestic refrigerators, ice-candy machines, refrigerated cabinets, air-conditioners and water coolers.
Some water coolers, central AC plants and cold stores use hydrochlorofluorocarbons such as HCFC-22. But HCFCs also have a definite ozone depleting potential and face an uncertain future. Nonetheless, some manufacturers say HCFCs could be used as a temporary substitute and are planning to switch to HCFC-22, which is manufactured locally and available easily.
Several industries like Kelvinator and Blue Star plan to tap into the Montreal Protocol's funds to finance changeover technology evaluations. However, the North does not encourage indigenous production of CFC substitutes. India's request for a research programme was deferred at a meeting of the Ozone Fund -- an international fund to replace ozone-depleting substances (ODS) -- in Bangkok last month. The North seems to be advocating that the fund be used by developing countries only to buy the technology to manufacture HFC-134a.
The Chinese government is promoting the use of another chemical -- HFC-152a -- which is also being viewed favourably by some Indian manufacturers, especially since it does not demand special lubricating oils. However, this fluid is both toxic and flammable and has been skipped in favour of HFC-134a in the US. As yet, it is an option listed in the MEF phase-out programme and studies are likely to be undertaken by several industries to judge its suitability.
The ubiquitous CFCs have not only been used as coolants, they have also been indispensable in insulating refrigerators from external temperatures. In traditional fridges, upto 80 per cent of the CFCs used were in the insulation foams. And, because the CFC-11 used to blow insulating foams is on its way out now, manufacturers are scrambling for substitutes for the much-vaunted PUF -- polyurethane foam -- used in most fridges.
Says Voltas' Iyer, "The situation with foams is in a greater state of flux." In the rigid foam sector -- which primarily services the refrigerator industry -- various alternative routes are under consideration. Manufacturers are looking at HCFC-22 based systems, blends of HCFC-22 and 142b, HFC-134a and cyclopentane, to mention a few. But they are yet to make the choice.
So, while governments wrangle over additional resources to fund the switchover to ozone-friendly CFC substitutes, refrigerator manufacturers wait and watch before committing themselves to any one option.