Lots of needs are being paid for how to design HVAC system in large-scale buildings. Increasing awareness of energy use is main point of this research. HVAC systems' energy characteristics are not clearly identified and understood, so the optimal design of HVAC system is very important. The energy parameters of HVAC design that are system input energy, water/air moving equipments (pumps/fans) energy and outdoor air conditioning energy for IAQ are important. The purpose of this study is to provide the basic data for energy conservational HVAC design strategies.