The cooling is usually reached through a refrigeration cycle, but in some cases evaporation or absolutely free cooling is made use of. Air conditioning devices can even be created determined by desiccants (chemicals which eliminate moisture from the air). Some AC programs reject or retail outlet warmth in subterranean pipes.[2] https://docs.google.com/spreadsheets/d/1sFkX-195bzbspltn6kI7pJAwHC_IWJIWy0giWMghe84