According to characteristic of heating, ventilation and airconditioning (HVAC), a way of building the structure of RBFFNN is proposed. The RBFFNN can accurately identify the model of HVAC, which has HVAC consume less energy under the precondition that the HVAC can adjust comfortable room temperature. An experiment shows that the RBFFNN can accurately identify the model of HVAC, when a system of HVAC has strong disturbs and changes of parmeters of model.