The energy consumption is a major concern to building facility managers. Regarding to hotels management, this is even more critical due to the close relation between hotel operation cost and profit. In Brazil, the use of air conditioning in hotels is almost mandatory due to climate demands even though, for certain hotels categories, the use of air conditioning system is optional. There are several tools that can be used for evaluating the energy demand of a building with air conditioning system. Among them, one can use EnergyPlus that has a detailed physical model for the building and a set of several models for different types of air conditioning and air handling systems. This paper proposes to evaluate EnergyPlus as a tool to predict the energy performance of an economic class hotel in Brazil with air conditioning system for different climate conditions. The results show that the level of uncertainty is quite customer dependent due to the variety of customer thermal comfort requirements.