The tombs of the kings in Valley of the Kings, Luxor, are considered to be one of the tourism industry's bases in Egypt due to their uniqueness all over the world. Hence, they should be preserved from the different factors that might cause harm for their wall paintings. One of these factors is the excessive relative humidity as it increases the bacteria and fungus activity inside the tomb in addition to its effect on the mechanical and physical properties of materials. The current research aims to study the mechanical ventilation systems effect on airflow pattern as well as temperature and relative humidity distribution inside three tombs. The study is carried out using computational fluid dynamics (CFD) simulation using a commercial CFD code, namely FLUENT(R) version 6.2.16. It was found that the optimum airside system design should allow the air to pass all the enclosure areas before being extracted. Also a restriction should be made for the simultaneous number of visitors for each tomb should be made in order to limit the relative humidity inside any given tomb.