## 4 Results and Analysis
### Hourly Electricity Consumption  
Because of the large size of profile data, the hourly analysis for the cooling load is divided into several steps to filter out the outstanding data to better analyze and compare the saving characteristics of the passive cooling techniques. The day where non-conditioning hours (7:00 AM to 13:00 PM every day between 1 November and 31 March) are excluded. First, the saving percentage of each passive cooling technique for each floor is plotted on three box-and-whisker charts based on the type of floor. The box-and-whisker charts show the median and the range of distribution of data over the hours and leave out points with large errors. The boxes show where 75% of points in a dataset act as an indicator for the variation pattern of the % difference. Next, the outstanding datasets are located, and their raw data are extracted for further analysis. The median value of the data (excluding the raw data) is calculated to exam the characteristics of these passive cooling techniques in hourly basics. The box-and-whisker graphs are attached in Appendix A, Appendix B, and Appendix C. The natural ventilation case is left out as the annual consumption result shows that it does not save energy. The detailed box-chart for the annual percentage difference distribution of cooling load vs. hours of days on ground floor for each test case can be found in Append A for Ground floor, Appendix B for Typical Floor, Appendix C for Top Floor. The analysis for the hourly characteristics of passive cooling techniques was mainly based on these charts for a general energy-saving potential in each hour of day. PCM shows a heating effect for the residential building during the nighttime on all three floors as in Figure 4. PCM can save around 3% of the cooling load in the afternoon from the melting of PCM. However, during the night, especially after 02:00, PCM increases the cooling load by 1-4%, which offsets the saving benefits in the afternoon. Shown in the box-and-whisker chart, the reduction in infiltration also shows a night-heating effect in certain periods. Unlike PCM, the night-heating effect for the reduction in infiltration only happens during the spring and autumn when a large daily temperature difference occurs. In this time, the infiltrated cool air in the nighttime provides natural ventilation to cool down the conditioned zones. The reduction in infiltration blocks this source of free cooling, subsequently increasing the cooling load in the nighttime on these particular dates. However, the median of _%diff_ in Figure 5 shows that the impact on the effectiveness of this method is marginal for annual energy reduction. If natural ventilation can be coupled with the reduction in infiltration to be the new source of free cooling, this particular increase in cooling load can be offset, further increasing the building's energy efficiency. As for insulation, the range of data shows an increase in cooling load from 13:00 to 15:00 for some days. The increase in cooling load also happens in spring and autumn. Similar to the infiltration, the reason for the increase in cooling load is the blockage of the source of cooling. In spring and autumn, the outdoor air is still not hot, and is cooler than the indoor air. The insulation layer reduces the U-value of the external wall, subsequently reducing the heat loss through the external wall on  
Figure 4: Hourly median for energy performance on different floors presented in percentage difference from benchmark after applying PCM. Note: _PCM_G—the difference for ground floor; _PCM_TYP—the difference for typical floor; _PCM_TOP—the difference for top floor. Figure 5: Hourly Median of percentage difference in total electricity after applying infiltration parameters. “Infil 0.3 G”—the data of the ground floor for the simulation run with 0.3 ach infiltration rate; and so on. these cool days.