This paper evaluates the energy and cost benefits for deployment of hybrid indirect evaporative and vapor compression systems for the existing Saudi residential building stock. Both experimental and simulation analyses are carried out to perform large scale energy, environmental, and economic assessments. The energy efficiency of the hybrid system is tested and measured under various operating conditions. The experimental data are then incorporated in a residential building stock model established for Saudi Arabia to quantify the energy, environmental, and economic performance of the hybrid systems relative to the current air conditioning systems. It is found through the testing analysis that the hybrid systems can double of the coefficient of performance of the vapor compression only air conditioning units especially when outdoor air temperatures are high. Moreover, it is estimated that the deployment of hybrid systems for Saudi residential building stocks achieves annual reductions of 51 TWh in electricity consumption and 38 million tons in carbon emissions with an average payback period of less than one year. ; The study presented in this paper is funded by KAUST Cooling Initiative, REP/3988/01-01.