{"id":104,"date":"2021-01-27T14:38:25","date_gmt":"2021-01-27T19:38:25","guid":{"rendered":"https:\/\/opentextbc.ca\/basichvac\/chapter\/gas-laws\/"},"modified":"2023-03-02T11:45:47","modified_gmt":"2023-03-02T16:45:47","slug":"gas-laws","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/basichvac\/chapter\/gas-laws\/","title":{"raw":"Gas Laws","rendered":"Gas Laws"},"content":{"raw":"Click play on the following audio player to listen along as you read this section.\r\n\r\nhttps:\/\/media.bccampus.ca\/id\/0_yqexxrs4?width=608&amp;height=80&amp;playerId=23449753\r\n\r\nBefore we can examine the inner workings of <strong>[pb_glossary id=\"146\"]direct expansion[\/pb_glossary]<\/strong> cooling systems, it will help to have a basic understanding of how fluids and gasses behave under different conditions. Specifically we are concerned with how changes in <strong>[pb_glossary id=\"148\"]pressure[\/pb_glossary]<\/strong>, <strong>[pb_glossary id=\"149\"]temperature[\/pb_glossary] <\/strong>or <strong>[pb_glossary id=\"220\"]volume[\/pb_glossary]<\/strong> will affect our cooling systems.\r\n\r\n<strong>Pressure<\/strong> is defined as a force acting upon an area. Expressed mathematically\r\n<p style=\"text-align: center;\">[latex]\\text{Pressure}=\\dfrac{\\text{Force}}{\\text{Area}}[\/latex]<\/p>\r\nPressure is directly proportional to the <strong>[pb_glossary id=\"150\"]force[\/pb_glossary]<\/strong>, in (N) newton\u2019s and inversely proportional to the [pb_glossary id=\"221\"]<strong>area<\/strong>[\/pb_glossary], in (m<sup>2<\/sup>) square meters, upon which it acts. By changing either the force or the area, we can vary the pressure of a system.\r\n\r\nTemperature is the <strong>[pb_glossary id=\"147\"]thermal energy[\/pb_glossary]<\/strong> contained by a material as its atoms collide with each other. It is a representation of kinetic energy. The hotter an object is, the more kinetic energy it atoms have, and the more collisions will occur.\r\n\r\nIt takes energy to heat something, and a hot object will slowly cool by dissipating its kinetic energy to the outside environment.\r\n\r\nTemperature is measured in either degrees Celsius (C\u00b0) or degrees kelvin (K\u00b0) . Kelvin is the base unit of temperature in the SI system.\r\n\r\nVolume represent the given space that something occupies. When describing gasses or liquids we often describe the volume that they take up. measured in cubic centimetres (cm<sup>3<\/sup>) or more commonly, (L) liters.\r\n\r\nWhen compared, we find that the temperature of a system is directly proportional to its pressure and inversely proportional to the volume that it occupies.\r\n\r\nExpressed mathematically:\r\n<p style=\"text-align: center;\">[latex]\\text{Temperature}=\\dfrac{\\text{Pressure}}{\\text{Volume}}[\/latex]<\/p>\r\nThis equation is a simplification of more complex gas laws, but will serve to illustrate the relationships that we wish to focus on.\r\n\r\nIn our DX cooling systems we will control the volume and pressure of a medium, the <strong>[pb_glossary id=\"231\"]refrigerant[\/pb_glossary],<\/strong> to transfer heat from one place to another.","rendered":"<p>Click play on the following audio player to listen along as you read this section.<\/p>\n<p><iframe loading=\"lazy\" id=\"kaltura_player\" title=\"4.32 Gas Laws\" src=\"https:\/\/api.ca.kaltura.com\/p\/148\/sp\/14800\/embedIframeJs\/uiconf_id\/23449753\/partner_id\/148?iframeembed=true&#38;playerId=kaltura_player&#38;entry_id=0_yqexxrs4&#38;flashvars[leadWithHTML5]=true&#38;flashvars[streamerType]=auto&#38;flashvars[localizationCode]=en&#38;flashvars[sideBarContainer.plugin]=true&#38;flashvars[sideBarContainer.position]=left&#38;flashvars[sideBarContainer.clickToClose]=true&#38;flashvars[chapters.plugin]=true&#38;flashvars[chapters.layout]=vertical&#38;flashvars[chapters.thumbnailRotator]=false&#38;flashvars[streamSelector.plugin]=true&#38;flashvars[EmbedPlayer.SpinnerTarget]=videoHolder&#38;flashvars[dualScreen.plugin]=true&#38;flashvars[Kaltura.addCrossoriginToIframe]=true&#38;wid=0_7iqjl75u\" width=\"608\" height=\"80\" allowfullscreen=\"allowfullscreen\" sandbox=\"allow-downloads allow-forms allow-same-origin allow-scripts allow-top-navigation allow-pointer-lock allow-popups allow-modals allow-orientation-lock allow-popups-to-escape-sandbox allow-presentation allow-top-navigation-by-user-activation\" frameborder=\"0\"><\/iframe><\/p>\n<p>Before we can examine the inner workings of <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_146\">direct expansion<\/a><\/strong> cooling systems, it will help to have a basic understanding of how fluids and gasses behave under different conditions. Specifically we are concerned with how changes in <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_148\">pressure<\/a><\/strong>, <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_149\">temperature<\/a> <\/strong>or <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_220\">volume<\/a><\/strong> will affect our cooling systems.<\/p>\n<p><strong>Pressure<\/strong> is defined as a force acting upon an area. Expressed mathematically<\/p>\n<p style=\"text-align: center;\">[latex]\\text{Pressure}=\\dfrac{\\text{Force}}{\\text{Area}}[\/latex]<\/p>\n<p>Pressure is directly proportional to the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_150\">force<\/a><\/strong>, in (N) newton\u2019s and inversely proportional to the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_221\"><strong>area<\/strong><\/a>, in (m<sup>2<\/sup>) square meters, upon which it acts. By changing either the force or the area, we can vary the pressure of a system.<\/p>\n<p>Temperature is the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_147\">thermal energy<\/a><\/strong> contained by a material as its atoms collide with each other. It is a representation of kinetic energy. The hotter an object is, the more kinetic energy it atoms have, and the more collisions will occur.<\/p>\n<p>It takes energy to heat something, and a hot object will slowly cool by dissipating its kinetic energy to the outside environment.<\/p>\n<p>Temperature is measured in either degrees Celsius (C\u00b0) or degrees kelvin (K\u00b0) . Kelvin is the base unit of temperature in the SI system.<\/p>\n<p>Volume represent the given space that something occupies. When describing gasses or liquids we often describe the volume that they take up. measured in cubic centimetres (cm<sup>3<\/sup>) or more commonly, (L) liters.<\/p>\n<p>When compared, we find that the temperature of a system is directly proportional to its pressure and inversely proportional to the volume that it occupies.<\/p>\n<p>Expressed mathematically:<\/p>\n<p style=\"text-align: center;\">[latex]\\text{Temperature}=\\dfrac{\\text{Pressure}}{\\text{Volume}}[\/latex]<\/p>\n<p>This equation is a simplification of more complex gas laws, but will serve to illustrate the relationships that we wish to focus on.<\/p>\n<p>In our DX cooling systems we will control the volume and pressure of a medium, the <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_104_231\">refrigerant<\/a>,<\/strong> to transfer heat from one place to another.<\/p>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_104_146\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_146\"><div tabindex=\"-1\"><p>A mechanical cooling system that uses the evaporation and condensation of a refrigerant to remove heat from an area.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_104_148\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_148\"><div tabindex=\"-1\"><p>The force acted upon an object or medium by the surrounding environment. Often measured in PSI or Pascal\u2019s.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_104_149\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_149\"><div tabindex=\"-1\"><p>A measure of the average molecular kinetic energy of a system on a definite scale. Measured in degrees Fahrenheit, Celsius or Kelvin.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_104_220\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_220\"><div tabindex=\"-1\"><p>The amount of space that an object or medium takes up. Measured in cubic units (cm3) or liters.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_104_150\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_150\"><div tabindex=\"-1\"><p>A pushing or pulling on an object, that when unopposed will result in a change in that objects velocity.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_104_221\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_221\"><div tabindex=\"-1\"><p>The surface of an object or medium. Measured in square units (m2).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_104_147\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_147\"><div tabindex=\"-1\"><p>The kinetic energy possessed by an object or mediums atoms and perceived as heat.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_104_231\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_104_231\"><div tabindex=\"-1\"><p>A material used in DX cooling systems that boils below room temperature, and is used to transfer thermal energy from one point to another.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":90,"menu_order":4,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-104","chapter","type-chapter","status-publish","hentry"],"part":96,"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/chapters\/104","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/users\/90"}],"version-history":[{"count":3,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/chapters\/104\/revisions"}],"predecessor-version":[{"id":358,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/chapters\/104\/revisions\/358"}],"part":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/parts\/96"}],"metadata":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/chapters\/104\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/media?parent=104"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/pressbooks\/v2\/chapter-type?post=104"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/contributor?post=104"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/basichvac\/wp-json\/wp\/v2\/license?post=104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}