Energy knowledge and university policies
Knowledge of energy terms
As shown in Fig. 3, we found that, on average, the surveyed students have competence knowledge (have certain knowledge or more) on global warming (t (266) = 8.9, p ≤ 0.0005), and have less knowledge (know little or none) on energy flexibility (t (266) = − 5.1, p ≤ 0.0005) and smart energy systems (t (266) = − 1.5, p < 0.05). meanwhile, they have certain knowledge on energy efficiency (t (266) = 1.5, p = 0.134) and the Danish energy goals (t (266) = − 0.89, p = 0.373).
Opinions on University energy policies and activities
82.8% of students believe the university has made an effort toward implementing energy savings (shown in Fig. 4). Although more than 20% of surveyed students do not have ideas about how active the university is in the energy efficiency of electricity and heating compared to other industries or commerce in the same city. The rest surveyed students, on average, believe the university is more active than others on the energy efficiency of electricity (t (211) = 9.96, p ≤ 0.0005) and heating t (206) = 11.96, p ≤ 0.0005).
92.1% of surveyed students do not know university policy regarding energy savings or energy efficiency, and 98.1% do not know any university energy savings incentive for the staff and the students. However, 80.9% of the surveyed students think students should take responsibility for energy savings at the campus, and 83.1% of surveyed students think the university should inform their employees and students regarding their energy policies.
Occupants’ preferences on students’ motivation for the acceptance of energy flexibility in campus buildings
According to Fig. 5, more than half of surveyed students believe ‘University plans to become a green intelligent university’, ‘University tries to reduce the energy consumption’, ‘University tries to reduce the energy bill, and will put the saved bill into campus facility improvement’ can motivate students to accept frequent indoor quality changes. Meanwhile, the image of ‘green intelligent university’ is the most popular motivation for students to accept frequent indoor quality changes. Comparatively, financial benefits to the university or students (reducing energy consumption, or saving energy bills to invest more in on-campus facility improvement) are less attractive for surveyed students.
Indoor comfort
Opinions on indoor comfort in classrooms
61.5% (comfortable or very comfortable) surveyed students are satisfied with the comfort level in the classrooms (shown in Fig. 6). Meanwhile, the surveyed students are satisfied with the current energy control on campus, and they think that the building system (e.g., shade adjustments) on campus does not disrupt their work. Although some surveyed students think that automatic light adjustment affects their concentration and work, many students still believe the automatic light adjustment is acceptable for their studies. However, female students have statistically significant less satisfied compared to male students regarding light distribution (U = 55,055, p = 0.034). Surveyed students slightly disagree that the rooms and campus, in general, are well ventilated.
Occupants’ preferences on frequent changes in indoor comfort
On average, surveyed students do not agree (the section is ‘maybe not’ in the questionnaire) either to change the classroom temperature or ventilation frequently. Meanwhile, surveyed students slightly disagree with adjusting lighting frequently in classrooms, but on average, they remain neutral. However, female students significantly disagree with the frequent lighting changes (U = 4618.5, p = 0.004). The surveyed students believe the frequent changes in indoor comfort in classrooms can influence teaching and learning performance (test value = 4 (maybe), (t(266) = 3.5, p = 0.001)).
Occupants’ preferences on locations of indoor comfort can be frequently changed
Hallways and canteens are the top two places the surveyed students choose and believe can be adjusted frequently and not influence students’ activities (shown in Fig. 7). Other areas, such as classrooms, auditoriums, labs, group rooms, and offices, are not positive for students to accept the frequent changes in temperature, light or ventilation. The surveyed students think lighting can be frequently changed compared to temperature and ventilation in hallway and canteen. However, it is the opposite when the situation refers to other locations, e.g., classrooms.
Building control system
Awareness of control systems installed in classrooms
The surveyed result (in Fig. 8) shows that, on average, the surveyed students are fully aware of the control systems installed in classrooms and their control options. For instance, the heating settings in classrooms are centrally controlled by the energy department in the university, and 63.74% of surveyed students are aware. Meanwhile, 80.5% of students are aware that there is no cooling thermostat installed in the class.
Opinions on energy control in classrooms
95.5% of surveyed occupants believe that they have full or partial control over lighting, but 61.8% and 63.7% of surveyed occupants believe that they have no control over cooling or heating (Fig. 9). On average, compared to male students, female students believe that they have less control over lighting (U = 4471, p ≤ 0.0005), cooling (U = 5147, p < 0.05), and heating (U = 5147, p < 0.005). Nevertheless, the surveyed students don’t think the building control systems significantly disrupt their work (t(266) = -3.50., p = 0.001).
Regarding lighting, surveyed occupants think the quality of the lighting is sufficient (t(266) = 9.44, p ≤ 0.0005), and the light is well distributed to all corners of the room (t(266) = 8.80, p ≤ 0.0005), although female students less agree (U = 55,055, p ≤ 0.05). Meanwhile, the automatic light adjustment seems like has no significant affect on students’ concentration and work (t(266) = − 1.38, p = 0.169). Compared to lighting, surveyed occupants are more sensitive to indoor temperature, that they believe too high or too low temperatures significantly affect their concentration and work (t(266) = 12.05, p ≤ 0.0005), and the temperature changes should depend on locations on campus (t(266) = 9.99, p ≤ 0.0005). One reason is might because the surveyed students don’t think the classrooms on campus are well ventilated (t(266) = − 1.96, p = 0.051) since some buildings are old and don’t comply with the new building codes.
Distributed energy resources
Occupants’ awareness of distributed energy resources on campus
The surveyed result shows (Fig. 10) that only a few students (35%) know there are solar panels installed on campuses, and due to the invisibility of the installed solar panels (on the roof) without notice by the university, students do not know the installation of solar panels on campuses. Meanwhile, few surveyed students believe there are other distributed energy resources installed on campuses, although they don’t see them. In fact, there are only solar panels installed on campuses so far.
Occupants’ preferences on the investment of distributed energy resources on campus
The surveyed students believe that the university should invest in solar panels (t(266) = 8.78, p ≤ 0.0005) and energy storage (t(266) = 2.586, p ≤ 0.01), and they have the neutral option or slightly disagree to invest on electric vehicle charging station/facility (t(266) = 0.738, p = 0.461) or wind turbines (t(266) = − 1.24, p = 0.217). Meanwhile, they are negative on the investment of combined heat and power (t(266) = − 2.59, p ≤ 0.01). 40.8% of survey students believe noises from wind turbines affect their concentration, and 36% believe not. There is no statistically significant relationship between the results and the gender, with two degrees of freedom = 2.10, p = 0.35. On average, surveyed students do not think the availability of electric vehicle charging on campus affects their choice of driving electrical cars (t(266) = − 2.21, p = 0.028).