## 4 EnergyPlus Simulation Results
### Analysis of Energy Saving Rate in Different Climate Zones
In addition, air-conditioning and plant systems that utilize outdoor air or ventilation, such as the combined VAV-economizer in Case 7 (42.9%), the active chilled beam with DOAS in Case 10 (56.8%), the high efficiency heating system in Case 11 (37.8%), CAV + GSHP in Case 14 (39.3%), and the active chilled beam with DOAS + GSHP in Case 15 (64.6%), are more efficient. In climates that have four distinct seasons, including a hot summer and a cold winter, thick insulation and solar heat should be utilized during the winter, whereas solar shading should be considered in summer. Furthermore, the plant and air-conditioning systems also need to be able to create a comfortable indoor environment in both the hot summer and cold winter. Therefore, a design strategy that fits the given climate is important. Comparison of Specific Energy Performance Simulation Results and Summary of Energy Saving Technologies in Different Climate Zones  
In Section 4.1, technologies that are effective in each climate were identified according to the simulation results. In Section 4.2, the technologies that were applied to a hot climate (New Delhi) and cold weather (Minneapolis) are compared with those in Incheon. In this section, the primary energy consumption values are divided into heating, cooling, and fan energy for the analysis of each component. Table 6 shows the specific energy consumption and saving rates in New Delhi (Hot humid zone_2A) and Incheon (Mixed zone_4A). When the high efficiency SHGC window was applied in New Delhi, the energy saving rate was 6.1% (16.0 - 9.9%) higher than that in Incheon. Among heating, cooling, and fan energy, cooling energy showed the highest saving of 23.4%. The solar heat gain coefficient (SHGC) of glazing systems is most influenced by the solar radiation. The influence is greater in hot regions, where the solar radiation is stronger than that in cold regions. Because the solar radiation is strong in hot and humid climate zones, SHGC is important for energy saving in the New Delhi climate. The energy saving rate of the external Venetian blind is 10.6% (26.0 - 15.4%) higher in New Delhi than that in Incheon. Among the three major components in New Delhi, the cooling energy saving is highest (38.4%). Shading systems, such as external blinds, are effective in reducing cooling energy consumption in hot and humid climate zones. Appropriate solar shading systems in hot regions can greatly contribute to save cooling energy consumption. Figure 11: Comparative results of the energy saving rates in the four regions when using high-performance technologies. The VAV system result showed 6.6% (\(36.5-29.9\%\)) more energy can be saved in New Delhi than in Incheon. In particular, the cooling energy and fan energy showed significant saving rates of 31.6 and 72.2%, respectively. When VAV systems were applied to office buildings in warm and hot climate zones (ASHRAE Climate Zone 1-3C), they showed relatively higher saving rates ([PERSON] et al. 2009). In addition, in a hot and humid climate (ASHRAE Climate Zone 1-2A), the VAV system was more effective than the CAV or FCU system ([PERSON] et al. 2018). When the VAV + ERV system was applied, 12.0% (51.3 - 39.3%) more energy was saved in New Delhi than in Incheon. The difference was caused by the fact that the VAV + ERV system removes a large amount of moisture when it is applied in New Delhi. The VAV + ERV system showed a cooling energy saving of 58.7%, and a fan energy saving of 66.4%. The ERV is more efficient in humid climates having large disparity between outdoor and indoor relative humidity than in dry regions. In particular, the ERV can effectively reduce latent heat load ([PERSON] et al., 2018). When the applicability of the ERV and HRV in various climates is considered, the ERV is more effective than the HRV in hot and humid climates. In intermediate seasons, when the difference between indoor and outdoor temperature is small, a by-pass control can be used ([PERSON] et al., 2018).