![\"\"](\"https:\/\/i0.wp.com\/tomdenton.org\/blog\/wp-content\/uploads\/2011\/08\/080711_1540_Refrigerant111.jpg?w=980\")
<\/p>\nThe ideal refrigerant has good thermodynamic properties, is unreactive chemically, and safe. The desired thermodynamic properties are a boiling point somewhat below the target temperature, a high heat of vaporization, a moderate density in liquid form, a relatively high density in gaseous form, and a high critical temperature. Since boiling point and gas density are affected by pressure, refrigerants may be made more suitable for a particular application by choice of operating pressure. These properties are ideally met by the chlorofluorocarbons. Corrosion properties are a matter of materials compatibility with the mechanical components: compressor, piping, evaporator, and condenser. Safety considerations include toxicity and flammability.<\/p>\n
Until concerns about depletion of the ozone layer arose in the 1980s, the most widely used refrigerants were the halomethanes R-12 and R-22, with R-12 being more common in automotive air conditioning. R-134a and certain blends have tended to replace the earlier compounds.<\/p>\n
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Most cars have a label stating the type of refrigerant used Following the ban on chlorofluorocarbons (CFCs) and hydro-chlorofluorocarbons (HCFCs), substances used as substitute refrigerants such as fluorocarbons (FCs) and hydrofluorocarbons (HFCs) have also come under criticism. They are currently subject to prohibition discussions on account of their harmful effect on the climate.<\/p>\n Natural refrigerants such as ammonia, carbon dioxide and non-halogenated hydrocarbons preserve the ozone layer and have no (ammonia) or only a low (carbon dioxide, hydrocarbons) global warming potential (GWP).<\/p>\n Emissions from automotive air-conditioning are a growing concern because of their impact on climate change. From 2011 on, the European Union will phase out refrigerants with a GWP of more than 150 in automotive air conditioning. This will ban potent greenhouse gases such as the refrigerant HFC (R-134a), which has a GWP of 1410. One of the most promising alternatives is the natural refrigerant CO2<\/sub> (R-744). Carbon dioxide is non-flammable, non-ozone depleting, has a global warming potential of 1, but is toxic and potentially lethal in concentrations above 5% by volume. GM has announced that it will start using Hydrofluoro-olefin (HFO-1234yf) in all of its brands by 2013. This new refrigerant has a GWP rating of 4.<\/p>\n GWP = 100 year warming potential of one kilogram of a gas relative to one kilogram of CO2<\/sub><\/strong><\/p>\n An interesting possibility for use as a refrigerant is air. With suitable compression and expansion technology, air can be a practical refrigerant, free of the possibility of environmental contamination or damage, and almost completely harmless to plants and animals. It is however not as efficient as other substances.<\/p>\n R134-a Refrigerant The ideal refrigerant has good thermodynamic properties, is unreactive chemically, and safe. The desired thermodynamic properties are a boiling point somewhat below the target temperature, a high heat of vaporization, a moderate density in liquid form, a relatively high density in gaseous form, and a high critical temperature. Since boiling point and gas density are […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[15],"tags":[],"class_list":["post-1189","post","type-post","status-publish","format-standard","hentry","category-automotive"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p79TdE-jb","jetpack-related-posts":[{"id":2515,"url":"http:\/\/tomdenton.org\/blog\/?p=2515","url_meta":{"origin":1189,"position":0},"title":"New Tech Promises to Boost Electric Vehicle Efficiency, Range","author":"Tom Denton","date":"September 24, 2016","format":false,"excerpt":"Researchers at North Carolina State University have developed a new type of inverter device with greater efficiency in a smaller, lighter package \u2013 which should improve the fuel-efficiency and range of hybrid and electric vehicles. Electric and hybrid vehicles rely on inverters to ensure that enough electricity is conveyed from\u2026","rel":"","context":"In "Automotive"","block_context":{"text":"Automotive","link":"http:\/\/tomdenton.org\/blog\/?cat=15"},"img":{"alt_text":"husain-inverter-2016-header-992x558","src":"https:\/\/i0.wp.com\/tomdenton.org\/blog\/wp-content\/uploads\/2016\/09\/Husain-inverter-2016-HEADER-992x558-300x169.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":709,"url":"http:\/\/tomdenton.org\/blog\/?p=709","url_meta":{"origin":1189,"position":1},"title":"Bosch Motorsport GDi","author":"Tom Denton","date":"November 16, 2010","format":false,"excerpt":"\u00b7 High-pressure injection valves with individual jet configuration \u00b7 Precise control of injection quantities \u00b7 For racing vehicles, Bosch Motorsport optimizes production-vehicle technology Bosch Motorsport is offering a new gasoline direct injection system for use in racing vehicles. With its engine control unit from the MS 5 product family and\u2026","rel":"","context":"In "Automotive"","block_context":{"text":"Automotive","link":"http:\/\/tomdenton.org\/blog\/?cat=15"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2330,"url":"http:\/\/tomdenton.org\/blog\/?p=2330","url_meta":{"origin":1189,"position":2},"title":"Facts about battery technology for hybrid and electric powertrains","author":"Tom Denton","date":"March 2, 2015","format":false,"excerpt":"How range is increasing, why a battery has more than one lifetime, and how automated driving could change battery technology Long service life, top quality, the highest degree of safety \u2013 we expect an enormous amount from high-voltage batteries in vehicles. That's why today's lithium-ion batteries, for example, have to\u2026","rel":"","context":"In "EV and Hybrid"","block_context":{"text":"EV and Hybrid","link":"http:\/\/tomdenton.org\/blog\/?cat=26"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1357,"url":"http:\/\/tomdenton.org\/blog\/?p=1357","url_meta":{"origin":1189,"position":3},"title":"Laser ignition","author":"Tom Denton","date":"March 28, 2012","format":false,"excerpt":"A company called Carinthian Tech Research (CTR) has developed a laser that can be used for engine ignition systems. Light is compressed to create a laser pulse, which because of the high energy density it generates plasma, which ignites the fuel. See the lightning spot in the video at: http:\/\/www.ctr.at\/en\/r-d-technologies\/laser.html\u2026","rel":"","context":"In "Automotive"","block_context":{"text":"Automotive","link":"http:\/\/tomdenton.org\/blog\/?cat=15"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1267,"url":"http:\/\/tomdenton.org\/blog\/?p=1267","url_meta":{"origin":1189,"position":4},"title":"Engine management barometric pressure sensors","author":"Tom Denton","date":"December 1, 2011","format":false,"excerpt":"Figure 1 Bosch SMP480 barometric pressure sensor (Source: Bosch Media) The new Bosch SMP480 barometric pressure sensor is extraordinarily small. It takes up just one-quarter of the space of its predecessor. This makes it easier than ever to include it in the electronic control units used in automotive technology. This\u2026","rel":"","context":"In "Automotive"","block_context":{"text":"Automotive","link":"http:\/\/tomdenton.org\/blog\/?cat=15"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1429,"url":"http:\/\/tomdenton.org\/blog\/?p=1429","url_meta":{"origin":1189,"position":5},"title":"Engine mapping \u2013 quick overview re Red Bull F1","author":"Tom Denton","date":"July 22, 2012","format":false,"excerpt":"The following is from one of my textbooks and refers to ignition timing \u2013 fig 10-17 shows a timing and dwell map (a similar method is used to determine engine fuelling. The F1 issue seems to be that the FIA regulations say that the 'looked up' (vertical axis) should be\u2026","rel":"","context":"In "Motorsport"","block_context":{"text":"Motorsport","link":"http:\/\/tomdenton.org\/blog\/?cat=23"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1189","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1189"}],"version-history":[{"count":3,"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1189\/revisions"}],"predecessor-version":[{"id":2139,"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1189\/revisions\/2139"}],"wp:attachment":[{"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1189"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1189"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/tomdenton.org\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1189"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n<\/strong><\/span><\/p>\n![\"\"](\"https:\/\/i0.wp.com\/tomdenton.org\/blog\/wp-content\/uploads\/2011\/08\/080711_1540_Refrigerant211.jpg?w=980\")
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\n<\/strong><\/span><\/p>\n
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