3.3.4. Step 4—Evaluation

Finally, from the data collected, the students need to consider the aspects necessary for its evaluation, such as calculations and regulations, and to investigate the necessary basic theory and numerical methods to obtain a baseline while comparing it with the specifications of the regulations.

*Example of obtained result: "In the last stage, the analysis of the CO2 concentration data was made, the results of both cases were verified with the international standards, ASHRAE 62 and 62.1, ASTM D6245-12* [56,57,61]. *Besides, some actions were designed that could be implemented to improve IAQ. CO2 concentration values, occupancy of 25 people, and the dimensions of the classroom were used to calculate the ventilation requirements per person. This number was compared with the ASHRAE 62 standard."*

From the development of these four steps, it is expected that the students will develop and apply the concepts, knowledge, and skills that correspond to their academic program. For example:


However, some assumptions and simplifications may be necessary to conduct the challenge. Specifically, the degrees of freedom must be clear, the type of sensors that are available (provide them with the sensors and guide them in obtaining the measurements), provide information regarding the study system, for example, current HVAC models and features in classrooms. Finally, the student must be provided with information on the available hours and the policies for the use of the rooms and the scope of the project.

No physical risks are expected from this challenge. Nevertheless, there is a risk that students will not adequately define the situation or the scope of the project. For example, to be aware of external factors that may affect their results or their proposals, such as the physical conditions of the city where they are conducting the study, meteorological conditions (temperature, humidity profiles), classroom characteristics (number of windows, dimensions, materials), description of the air conditioning system, georeferencing, etc. Thus, the professor must play an essential role in guiding the students with questions that may motivate them to make more in-depth insights into the solutions that they are proposing, in order to help them to develop the desired competencies.

#### *3.4. Challenge Implementation Results*

The challenge was implemented during August 2019–June 2020. A team consisting of three 9th-semester Mechanical Engineering students was assigned to solve the Smart Energy challenge. Some results of the challenge and the student experience from the teacher's perspective are discussed below.

Figure 6 shows that the students were able to obtain data through low-cost sensors. However, they did not demonstrate the same ability in the use of Matlab® to interpolate the conditions at points where there was no sampling, nor the use of scales to demonstrate a real behavior of CO2 concentration. During the challenge, it was noted that the students struggled to use the mathematical equation to calculate the number of room air changes necessary to maintain the CO2 concentration at acceptable levels, according to regulations. However, they demonstrated competency in database consulting.

**Figure 6.** CO2 concentration profile in two classrooms at Tecnologico de Monterrey.

An excerpt of the students' conclusions is presented below:

*"Inexpensive sensors were used to perform classroom measurements that measure CO2 concentration, temperature, and percentage of humidity within the classroom. According to the data obtained, color maps were constructed in Matlab® to visualize the CO2 concentration during a class session. The concentration of CO2 remains over 2000 ppm, reaching a peak value of up to 2883 ppm in the afternoon, which is well above the limit recomended by the regulations that tell us the standard of 1000 ppm."*

*"Likewise, calculations of the liters of air per second that each person should have in the room were made. Taking into account an average concentration from outside such as 400 ppm, the highest amount of CO2 concentration, and the variable found with the average weight and height of a Mexican, we obtain 2.17 L per second for each person, being well below what gives us the regulation of 5 L per second per person."*

*"The air quality inside the classrooms of the Tecnologico de Monterrey is not adequate to ensure the well-being of its occupants. For this reason, it is proposed that installed air conditioners achieve adequate ventilation so that students and teachers have the security that they will stay healthy and that academic performance increases. Likewise, a filter system in the air conditioners capable of eliminating viruses is necessary to avoid contingencies such as COVID. In this way, students and teachers will feel protected by the Institution since the necessary hygiene measures will be taken to eliminate any virus."*

The COVID-19 Pandemic affected the normal development of the Smart Energy Challenge since by the middle of spring 2020 students could not ge<sup>t</sup> access to the campus and therefore, they could not obtain new data. This fact affected their motivation, and their achievements were much lower compared to the students that had participated in the previous semester (fall 2019).

#### *3.5. Discussion on the Challenge Implementation and Results*

The students made fair use of the instrumentation that was available to them. They also designed and manufactured an interconnected system of low-cost sensors to obtain CO2 concentration, temperature, and humidity data in the cloud. In addition, they compared this data with the recommended values defined by international organizations.

It was observed that students focused on CO2 concentrations, while their analysis does not take into account temperatures or humidity concentrations, and gave more value to the health aspect than to the energy aspect. This situation was expected, since the challenge had double goals, which in this case was not only to propose alternatives to improve indoor air quality but also to validate the energy efficiency of these solutions. One possible explanation for the student' performance could be that the time available for the challenge was not enough, nor was the emphasis given to specific topics such as sensors and not energy aspects. This is an area of opportunity for the present challenge.

In terms of motivation, the students appeared to be encouraged and willing to show their results to share the importance of making improvements in the ventilation of the classrooms. Proof of that was submitting their work to the *Conexión Tec* contest. It is carried out every semester organized by Tecnologico de Monterrey to connect students and industry through their classroom projects. In the next version of this challenge, designers will include tools to evaluate the effect of the challenge on the students´ engagemen<sup>t</sup> on the proposed topics. Finally, from the technology side, students demonstrated that the classrooms that they monitored had problems in their HVAC system and that those problems affect students' performance and will limit the use of these classrooms in the post-COVID era. Future challenges will focus on providing alternative solutions for Tecnologico de Monterrey administrators.

The following section presents the overall findings and learnings of the implementation of the Campus City and Challenge Living Lab framework. This includes the stakeholders perspective and involvement, as well as the perspectives from the professors and students that carried out the challenges.

#### **4. Findings and Learning**
