1)Fluorinated gases (F-gases) are artificial gases. There are four types: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6) and nitrogen trifluoride (NF3). The most widely used are HFCs, which account for about 95% of F-gas emissions, while SF6 and PFCs account for roughly 3% and 2% of F-gas emissions respectively. NF3 account for a very small amount of emissions.
2)HFCs are mainly used as refrigerants in refrigeration, air conditioning and heat pump applications. They can also be used as a blowing agent in the production of insulation materials and as propellants in aerosols and medical appliances, such as inhalers. Though the Global Warming Potential (GWP) of some HFCs can be as great as 14,800 times that of carbon dioxide, the most widely used HFCs are substantially less, usually between 1,000 and 4,000, and can remain in the air for up to 270 years. One of the most widely used HFC refrigerants—HFC-134a has a GWP of 1,430 and persists for 20 years. Other key HFC refrigerants include: R-404A (GWP 3,922); HFC 507 (GWP 3985), R-410A (GWP 2,088) and R-407C (GWP 1,774). Examples of HFCs being used as blowing agents include HFC 245fa (GWP 950) or HFC 365mfc (GWP 794).
3)HFCs are used in a variety of sectors for refrigeration purposes, which require different loads. Domestic refrigeration includes refrigerators, freezers and fridge/freezers and typically use. between 0.05 and 0.25 kg of refrigerant, usually HFC 134a. The commercial sector (e.g. supermarkets, petrol stations, small shops, pubs, hotels, restaurants) use a variety of appliances ranging from small hermetically sealed systems (e.g. ice cream freezers and stand-alone retail displays) to large central pack systems, used in supermarkets and large stores to cool numerous display cases. While small units may use between 0.1 Kg and 0.5 kg of HFC 134a or HFC 404A, a larger unit may use in excess of 100 kg of HFC 404A. Industrial uses cover: food and drink; manufacturing; chemicals; petrochemicals; pharmaceuticals; printing; plastic mouldings. Industrial processes are also used in nonindustrial sectors such as cold storage, ice rinks and ski centres. Specific uses include large central systems serving several major loads (e.g. blast freezing and large cold stores), large chiller systems and smaller dedicated plants, each serving a single cooling appliance. Loads can range from several tonnes to less than a 100 kg of refrigerant, typically HFC 404A and HFC 507. The transport sector is also a significant user of refrigerants, usually HFC 134a or HFC 404A, to transport chilled goods.
4)HFCs are also used in air conditioning appliances. Single split systems, which consist of an indoor cooling unit connected to an outdoor condensing unit (compressor and condenser) tend to use. HFC 410A and a refrigerant charge of between 1 kg and 5 kg. Large split systems and packaged units, which includes a range of direct expansion air conditioning systems, also typically use HFC 410A with a refrigerant charge of between 5 and 50 kg. Chiller systems., which are usually used to cool large buildings, using chilled water as a secondary refrigerant, often use HFC 134a and have typical refrigerant charges between 50 kg and 500 kg. Systems which use smaller chillers might use HFC 410A or HFC 407C and have charges of between 5 kg and 50 Kg. Hermetically sealed movable air-conditioning systems.—small integral air-conditioning units that can be moved between different rooms in a building, usually use HFC 134a or HFC 410A and have refrigerant charges of well under 1 kg. The mobile air conditioning sector is also a major user of HFCs, primarily HFC 134a, and covers road vehicles and other modes of transport such as trains, ships and aircraft.
5)HFCs refrigerants are also used in heat pump systems to absorb, transport and release heat. This includes air source, ground source and water source heat pumps for building heating. Domestic systems often use HFC 410A and typically have a refrigerant charge between 3 kg and 5 kg. Larger systems, using various refrigerants, are used in commercial, industrial and public buildings. Other HFCs used in heat pumps include HFC 134a, R-404A and R-407C. HFCs also have uses in specialised fire protection equipment, where, for example, building contents have a high value and other fire protection systems could cause too much damage. They are also used as small automatic fire extinguishers (e.g. bus engines, small boat engines and motor sports) and as hand held extinguishers.
6)PFCs are a group of man-made chemicals containing the two elements carbon and fluorine. Under normal environmental conditions they are generally colourless, odourless, non-flammable, unreactive gases. The main releases of PFCs to the environment occur during the manufacture of semi-conductors, specialist refrigeration equipment and the production of aluminium. They have a GWP of between 7,390 and 12,200. PFCs are used as etching/cleaning gases in various microelectronic and semi-conductor manufacturing processes. PFCs are also used to make fluoropolymer coatings that resist heat, oil, stains, grease, and water for a range of products such as clothing, furniture, adhesives, food packaging, heat-resistant non-stick cooking surfaces, and the insulation of electrical wire. . They also have several medical and pharmaceutical uses, including blood substitution, ventilation and for delivery of gas-based therapeutics.
7)SF6 is an inorganic, colourless, odourless, non-corrosive and non-flammable gas. It is also an excellent electrical insulator. It has a GWP of 22,800. SF6 is used in the design of high and medium voltage switchgears because of its size and weight reduction and its quiet and reliable handling and maintenance. It is also used for magnesium casting, as it helps forms a protective atmosphere to prevent the formation of undesirable by-products. Other foundry applications include aluminium casting and as a refining and degassing agent. SF6 is applied in the semi-conductor industry, as an etching gas for plasma etching or as a cleaning gas to clean the chambers after the etching process. Several other minor industrial applications include leak detection as a tracer gas and the manufacture of loud speakers and lasers. Medical applications include its use as a contrast agent for ultrasound imaging and as an injection in vitreoretinal surgery to restore the vitreous chamber.
8)NF3 is a colourless, odourless, non-flammable gas. It has a GWP of 17,200. It is used as a cleaning agent in the plasma etching of silicon wafers and is predominantly applied to the manufacture of high-volume liquid-crystal displays and silicon-based thin-film solar cells. It is also used in hydrogen fluoride and deuterium fluoride lasers, which are types of chemical lasers.
163 Gluckman Consulting, , (2014). See also EFCTC, , (accessed 26 February 2018).
164 Gluckman Consulting, , (2014). See also EFCTC, , (accessed 26 February 2018).
165 Gluckman Consulting, , (Updated January 2015). See also EFCTC, , (accessed 26 February 2018).
166 Gluckman Consulting, (2014). See also EFCTC, , (accessed 26 February 2018).
167 Gluckman Consulting, , (2014).
168 Gluckman Consulting, , (2014).
169 See EFCTC, , (accessed 21 February 2018).
170 Gluckman Consulting, , (2014).
171 Scottish Environment Protection Agency, , (accessed 26 February 2018).
172 United States Environmental Protection Agency, , (accessed 26 February 2018).
173 Wen-TienTsa et al, , Journal of Loss Prevention in the Process Industries, Vol 15 Issue 2, (March 2002).
174 See: Centers for Disease Control, , (accessed 20 February 2018).
175 See UNPCC, , (accessed 21 February 2018); MP Hlastala, and JE Souders, JE, “Perfluorocarbon Enhanced Gas Exchange: The easy way”. American Journal of Respiratory and Critical Care Medicine. Vol 164 No 1 (July 2001), p 1–2.
176 United States Environmental Protection Agency, , (accessed 26 February 2018).
177 Gluckman Consulting, , (2014) and EFCTC, , (accessed 21 February 2018).
178 Gluckman Consulting, , (2014).
179 See: EFCTC, , (accessed 20 February 2018).
180 As above.
181 See: PubChem, , (accessed 20 February 2018).
182 United States Environmental Protection Agency, , (accessed 26 February 2018).
183 See: Air Products, , (accessed 26 February 2018) and Gas World, , (July 2008); Prachi Patel-Predd, , Scientific American, (2008).
184 UNPCC, , (accessed 21 February 2018)
Published: 25 April 2018