One　major　reason　for　the　limited　application　of　adsorption　refrigeration　systems　is　their　lower　refrigeration　efficiency　and　performance　compared　to　other　alternatives.　Additionally,　there　is　limited　research　focused　on　optimizing　the　system　performance　over　time.　This　paper　presents　a　numerically　validated　thermodynamic　model　to　analyse　the　effect　of　adsorption　time　on　the　performance　efficiency　enhancement　of　a　solar　adsorption　refrigeration　system.　The　adsorption　rate　model　proposed　by　Sokoda　and　Suzuki　has　been　used　to　evaluate　the　adsorption　and　desorption　characteristics　of　water　vapor　on　silica　gel　and　the　solar　collector　system　has　been　fitted　to　a　heat　flow　density　equation　based　on　measured　concentrated　solar　heating.　The　water　vapor　adsorption　capacity　on　silica　gel　as　a　function　of　temperature　and　pressure　in　the　adsorption　bed　has　been　numerically　evaluated　during　the　four　stages　of　the　cooling　cycle,　namely　adsorption,　preheating,　desorption,　and　cooling.　The　coefficient　of　performance　and　specific　cooling　power　have　been　utilized　as　the　major　performance　in-dicators,　in　the　context　of　the　influence　of　adsorption　time　on　the　refrigeration　performance　of　the　system.　The　simulation　results　revealed　that,　although　increasing　the　adsorption　time　increased　the　system＇s　cooling　capacity,　it　also　prolonged　the　cycle　time　and　adversely　affected　the　dynamics　of　preheating　and　desorption　processes　(due　to　increased　solar　input).　As　a　result　of　the　numerical　simulation,　an　optimum　value　of　adsorption　time　has　been　predicted　to　be　71　min　corresponding　to　a　coefficient　of　performance　equal　to　0.476　anda　specific　cooling　power　equal　to　28.6　W/kg.