Commercial park energy management systems (CPEMS) can reasonably plan appliances’ schedule of commercial tenants (CT) and lower their electricity purchasing cost. However, in the existing models, thermodynamic equipment like air conditioners and water heaters are not precise enough, failing to reflect the actual operating characteristics of the equipment. This paper presents an energy management system model including thermodynamic equipment. By coordinating the electricity consumption schedule of multiple CTs, CPEMS can reduce CTs’ electricity purchase costs. In the demonstration example, electricity purchase costs of CTs are reduced and operators of CPEMS gain profit, proving the feasibility of the model.