<Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2016) (Learn how and when to remove this template message) </Td> </Tr> <P> In the refrigeration cycle, heat is transported from a colder location to a hotter area . As heat would naturally flow in the opposite direction, work is required to achieve this . A refrigerator is an example of such a system, as it transports the heat out of the interior and into its environment . The refrigerant is used as the medium which absorbs and removes heat from the space to be cooled and subsequently ejects that heat elsewhere . </P> <P> Circulating refrigerant vapor enters the compressor, where its pressure and temperature are increased . The hot, compressed refrigerant vapor is now at a temperature and pressure at which it can be condensed and is routed through a condenser . Here it is cooled by air flowing across the condenser coils and condensed into a liquid . Thus, the circulating refrigerant removes heat from the system and the heat is carried away by the air . The removal of this heat can be greatly augmented by pouring water over the condenser coils, making it much cooler when it hits the expansion valve . </P>

Which gas is used in refrigerator and ac