This paper explores the effectiveness and energy consumption of three types of HVAC systems for summer cooling: fan cooling, split air conditioning (AC) system, and radiant system. The study focuses on evaluating the comfort level and energy efficiency of these systems using simulations. The simulations consider an office room with an occupant and analyse human body temperature distribution, air flow distribution, and energy consumption. Computational fluid dynamics (CFD) method is used for the simulations, considering various factors such as air conditioning equipment, room dimensions, and occupant characteristics. The findings provide valuable insights into the performance of different HVAC systems for achieving optimal comfort and energy efficiency in buildings.