Abstract: In order to systematically analyze the effect of setting exhaust heat recovery device on the overall energy consumption of the central air conditioning system, the central air conditioning system with air-cooled chiller as cold source is selected as study object. On the condition of meeting the requirement of the thermal comfort and indoor air quality, the energy flow mathematical models for this central air conditioning system with and without setting device of exhaust heat recovery are established through analyzing the energy flows of the four consecutive loops which extract energy from the conditioned spaces and reject it to the environment. Based on the HVAC design parameters of a commercial building in Guangzhou, the energy flow diagrams of this air conditioning system with and without exhaust heat recovery are drawn respectively, which can visualize the main differences of energy flow and energy consumption between different systems and provide useful messages for selection and energy saving potential of the system.

Key words: heat recovery, central air conditioning system, air-cooled chiller, mathematical models, energy flow