In this paper, improving the overall heat transfer coefficient by adding aluminum species to silica gel has been studied theoretically. An adsorption desalination system is proposed, and a lumped theoretical model conducted to investigate employing the metal additives within the adsorbent bed with and without a heat recovery between condenser and evaporator. A 30% of the total mass of the adsorbent bed contents was considered to be replaced by aluminum species. According to this, the overall heat transfer coefficient has been increased by 260%, which shows a good impact on the performance of the adsorption system. Daily water productivity was increased by 70% at the worst-case, reaching up to 17 m3/day/ton of silica gel without heat recovery. By employing heat recovery with the metal filing, the daily water productivity reached 42 m3/day/ton of silica gel which is four times the productivity of the classic silica gel-based adsorption desalination system.