Journal of Korean Institute of Architectural Sustainable Environment and Building Systems ISSN:1976-6483(Print) 2586-0666(Online) 한국건축친환경설비학회논문집

The economizer is one of the energy saving methods through the operation of HVAC system. When the economizer is applied, the energy is saved as compared with the case without it. Currently, it is suggested as a recommendation of the energy saving design standard of the building, which is a domestic regulation. However, In Korea, it is not applied universally compared to other countries and it is applied to some skyscrapers but it is not operated properly because it is not operated or operated passively by manager's experience. The conventional control method of the economizer system presented the supply air temperature constantly, but it is considered that additional energy saving is possible compared with the previous control method as the supply air condition is changed according to the load condition. Therefore, in this study, we evaluated the energy saving effect by changing the supply air temperature according to the outdoor condition in the economizer dry bulb temperature and enthalpy control method of CAV and VAV systems. For this, BIN method was used and the cooling, fan, and heating energy were analyzed. Based on the results, the supply air temperature according to the outside temperature was derived. The derived supply air temperature methods and the existing economizer control methods were analysed by evaluating the energy. As a result, it was confirmed that both the dry-bulb and enthalpy economizer can save energy compared to the existing method in CAV and VAV systems.