This paper is a study of the air temperature distribution of an air-conditioned office room equipped with a double-glazed window in a desert climate. The study includes both experimental and theoretical works using a computational fluid dynamics (CFD) simulation program. The experimental results were compared with the CFD program results. The commercial computational fluid dynamics ANSYS CFD V.13.0, solver FLUENT software, and three-dimensional flow finite difference of k-e for analysis and validation experimental work were used. The main objective of the study is to evaluate the temperature difference between the outdoor and indoor environments, as well as the distribution of air temperature in the room. The computational results for internal air temperatures of the office ranged from 23°C to 26°C, while the airflow velocity was low at less than 0.3 m/s. The temperature differences between the indoor and outdoor spaces varied between 9 °C and 15 °C. Good agreement was achieved between the computed and measured temperature results. The error percentage varied from 0.3% to 0.8%. The experimental and numerical results showed that well-designed double glazing can reduce the emission of sunshine and heat inside desert buildings, even using the northeastern facade, in sunny climates.