5.4 Evaluation of Proposed Solution
Evaluation involves the installation of the PIR motion sensor in classrooms only. For that, the team has come up with a few projected challenges that SIT@Dover and its students would face.
5.4.1 Cost of Rewiring the Main Electric Circuit
Although PIR sensors are very cheap, the cost of hiring professional electricians to perform the rewiring works is expensive, considering a large number of classrooms. However, the costs can be earned back from the savings incurred over the years of saving electricity by cutting unnecessary wastages.
5.4.2 Disruption of Classes
Electrical works may disrupt certain classes from having their lessons in the particular classrooms where the works may be done. In order to mitigate this, the electrical works may be done either on weekends or after office hours, where there are very few, if not zero, classes going on. Another possible solution is to liaise with the administrative division on the schedule of classes.
5.4.3 Unexpected and Unwanted Switch Off
As supported by the team’s survey, students have opined that the lighting units may switch off in the midst of classes, where there is minimal movement. This may be true only when there are very few students in a classroom. When a classroom is packed with more students, there is a larger tendency for movement to occur within a span of 15 minutes, triggering the motion sensor to keep the lights turned on.
5.4.4 Classrooms Used as Sleeping Areas During Camps
During student orientation camps, classrooms are used as sleeping areas for campers and also act as important rooms (i.e. operations room, logistics room) for the camp committee members. For this reason, lights should remain turned off even if there is movement in the room to prevent campers from waking up due to sudden light exposure. In order for this to happen, a master switch can be fitted into the main electrical circuit as well for each individual classrooms, as shown in Figure 4. This will help deactivate the motion sensor and control the lighting units in accordance to what the user wants. This feature should only be used in such special circumstances, but not on ordinary days.
Figure 4. Circuit diagram of a master switch with PIR sensor.
This report follows wholly on the information and research gathered using the following methods:
6.1 Obtaining Photographic Evidence in SIT@Dover
Our team, on random days, stayed in school up to 9pm to investigate the different areas of the school, mainly the University Services Centre and Academic Plaza. We then took pictures of the classrooms where lighting units were left turned on. These classrooms would be the places where the PIR motion sensors are installed.
6.2 Identification of Students’ Opinions
A survey was conducted by our team on students’ habits (if they turn off the lights), and their feedback on having motion sensors in classrooms to control the lights was taken into account. The results were then analyzed and used to support the notion that motion sensors in classrooms would help the institute to cut utility costs.
6.2 Research through Online Research
In order to recommend solutions for the institute, the team did online research to find, compare and select the most suitable product. Each of the product was carefully evaluated through a number of considerations and conditions identified by the team.
The proposed solution to energy conservation in SIT@Dover involves installing an automated motion sensor system where PIR sensors can control the utilities of classrooms. This would significantly reduce the institute’s electricity consumption. Although there are limitations to such a system, they are either temporary or easily overcome. Also, the advantages outweigh the limitations in the long term. In retrospect to the institute’s shift to the new Punggol campus, the stipulated date shifting remains unfixed. Thus, it is critical for the institute to minimise energy consumption as much as they can. Therefore, the proposed solution would definitely aid SIT@Dover in advancing toward a more technological and greener environment, where cost-saving and energy conservation serves a win-win situation for both the environment and the institute.
Agarwal, T. (n.d.). What are motion sensors and how do they work. Elprocus. Retrieved from https://www.elprocus.com/working-of-different-types-of-motion-sensors/
Aggarwal, N. (2017). Exposing students to clean energy technologies and practices. Business Times. Retrieved October 18, 2017, from http://www.businesstimes.com.sg/hub/energy-efficiency-national-partnership/exposing-students-to-clean-energy-technologies-and
Aggarwal, N. (2017). Ministry of Finance leading the way in energy-efficiency practices. Business Times. Retrieved October 18, 2017, from http://www.businesstimes.com.sg/hub/energy-efficiency-national-partnership/ministry-of-finance-leading-the-way-in-energy-efficiency
HowStuffWorks. (n.d.). How do motion sensing lights and burglar alarms work? HowStuffWorks.com. Retrieved from: https://home.howstuffworks.com/home-improvement/household-safety/security/question238.htm
Johnson, S. (April 24, 2017). Advantages and disadvantages of infrared detectors. Sciencing. Retrieved from https://sciencing.com/advantages-disadvantages-infrared-detectors-6151444.html
PIR Sensor. (March 11, 2016). Tech.faq. Retrieved from http://www.tech-faq.com/pir-sensor.html
Safewise.com. (n.d.). The Beginner’s Guide to Motion Sensor. Safewise.com. Retrieved from: https://www.safewise.com/resources/motion-sensor-guide
Figure 5. Survey question 1
Figure 6. Survey question 2
Figure 7. Survey question 3
Figure 8. Survey question 4
Figure 9. Survey question 5
|Selection of idea|
|Survey & Interview|