DescriptionData center is a facility that has high energy demands to keep the temperature under control. IT equipment consumes 50% of energy while the cooling system consumes approximately 37% of energy. Hence, it is very important to ensure the cooling of the data center is efficient. In this research, the effect of operating parameters such as inlet velocity, inlet temperature and porosity of the racks on the temperature distribution is studied; furthermore, the effect of different load distribution in the racks and the transient effects during load change are studied. A raised floor data center is modeled and thermal simulation is done using ANSYS FLUENT. The research consists of two parts, the first part aims at developing a working steady state model of a data center by modeling the racks as porous media and studying the temperature distribution of the racks and the room with varying load and different operating parameters for steady state condition. The optimal load distribution on the racks for different utilization is identified. In the second part, a transient state analysis is done in order to understand the change in the system when the load changes. In a data center, the racks do not always operate at 100% and hence most of the temperature issues come when the load increases suddenly. Therefore, it is important to study the transient effects when the load is increased.