*3.3. Challenge Methodology*

Students were provided with a general strategy as a guide or methodology. The strategy involved four steps described in the following subsection, including a brief example of the information that would be expected from the students (text in italic format).

#### 3.3.1. Step 1—Study Case 3

The first stage is the definition of the boundary conditions required to solve the challenge. Moreover, the students are required to define the type and number of study rooms, the location of the study, the scenario in which they will carry out measurements and analysis, as well as the specific identification of the energy system to be studied.

*Example of obtained result: "In this work, we analyze two classrooms classified as nonresidential buildings located at the Tecnologico de Monterrey, Campus Monterrey, Mexico. These classrooms correspond to the buildings A and B, both with northwest orientation, the number of occupants per class is 15 and 25, respectively. The installed HVAC systems have a constant evaporator and enthalpy, are kept continuously in operation to maintain the comfort of the occupants when modulating the equipment injection."*

## 3.3.2. Step 2—Instrumentation

In this step, the students must list how they intend to monitor current conditions to determine the baseline to be compared with ideal situations.

*Example of obtained result: "Particle devices, Xenon, and Boron modules were used. Through a communication protocol I2C and the SCD30 sensor, real-time monitoring of the CO2 concentration (ppm), temperature, and relative humidity of the classrooms will be performed."*

#### 3.3.3. Step 3—Monitoring Campaign

The students are advised to carry out a monitoring campaign, using the proposed instrumentation while considering the moment, duration, location and number of the monitoring instruments and the frequency of data acquisition to construct the baseline. It is worth noting that the students must justify each decision and assumption made based on the literature available.

*Example of obtained result: "Case A was monitored on November 15 and 22, 2019, for 100 min from 08:30 to 10:10 a.m. The monitoring time for Case B was 90 min, on November 12, 22, and 26, from 4:05 to 5:35 p.m. The placement of sensors varies, depending on the number of occupants and the size of the classrooms. An SD card incorporated into the Boron module was used to collect the data in real-time. Data were captured every 10 s."*
