## 3 Results  
The electric equipment installed in the experiment room consisted of eight 23 W bulbs and six exhaust fans of 80 W each with daily operation of 14 hours from 7:00 a.m. to 21:00 p.m. Sensors are installed next to the lamp, as shown in Figure 2(a). Measurement for the illuminance (lux) of the installed lighting uses lux meter placed under each lamp at a height of 1 m above the floor which shows the readings of the measurement in illuminance as shown in Figure 2(b). Highest illuminance readings recorded are for under the lamps near the outside window, with lowest reading at the cubicle furthest away from both window and outside door. The accuracy of the lux meter is within \(\pm\)6%. For each measurement, stable numerical values are obtained. At the time of measurement, the door of the restroom and room lighting is set to be as close as possible to the normal working condition.  
Total power consumption is 664 Watt-hours, which translates into 0.664 kWh in one hour or 9.3 kWh/day, or on average 231 kWh/month and 2772 kWh annually. Baseline Measurement is taken and recorded with 7-hour interval up to 84 h equal to a 6-day week of operation. During this period, total electric power consumption is amounted to 55.576 kWh without the use of motion sensors [1]. Measurement for low usage period during the semester break, where usage is minimum, yields 20.229 kWh and with a carbon emission factor of 0.00785, calculation on the annual carbon reduction resulted from the use of motion sensors is 36 tons/year. Measurement for high usage period is taken during the first days of the new academic year, the busiest days where the maximum number of students are present to attend their first week of courses. Measurement taken in September with the same interval yields 38.854 kWh.  
During measurement with sensors on Monday, 1 August 2016 at 8:00 a.m., with all lamps except ones near the toilet door being off and only the exhausts operating, the power meter reading shows 304.2 W and total consumption is 504.49 Wh. This reading is within reduction range after 1 h of operation (0.504 Wh vs 0.664 Wh). Measurement taken on Wednesday, 3 August 2016 at 14:30, after 35 h of operation, shows a 10.6 kWh of consumption versus 27.9 kWh for normal operation. The measurement data is shown in Table 1 and plotted in Figure 4. From Table 1, it can be seen that reduction to half of the normal consumption is achieved after 28 h. By the end of the week, the reduction reached 63.73%. As for high usage condition measurement starting from 5 September 2016, the saving for the first day (14-hour) operation yields only 18% reduction and by the end of the measurement period, the average saving is only slightly above 25%.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Duration (hours)**} & \multicolumn{2}{c}{**Electrical Power (kWh)**} & \multirow{2}{*}{**Energy Reduction (\%)**} \\ \cline{2-3} \cline{5-3}  & **With Sensor** & & **Without Sensor** \\ \hline  & 0.504 & 0.664 & 24.10 \\
7 & 2.711 & 4.648 & 41.67 \\
14 & 5.058 & 9.296 & 45.59 \\
21 & 7.158 & 13.944 & 48.66 \\
28 & 8.890 & 18.592 & 52.18 \\
35 & 10.622 & 23.24 & 54.29 \\
42 & 12.264 & 27.888 & 56.02 \\
49 & 13.816 & 32.536 & 57.54 \\
56 & 15.278 & 37.184 & 58.91 \\
63 & 16.651 & 41.832 & 60.20 \\
70 & 17.933 & 46.48 & 61.42 \\
77 & 19.126 & 51.128 & 62.59 \\
84 & 20.229 & 55.776 & 63.73 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Power consumption data comparison without sensor installation and after the sensors installation [1].  
Figure 3: (**a**) Motion sensor installation next to each lamp; (**b**) Illumination measurement for points under each individual lamp; the ones with higher illuminance are near the window, showing a significant difference, with the darkest point being the one furthest away from the window and outside door.