Association of indoor temperature and air quality in classrooms based on field and intervention measurements

Experimental Study of Indoor Air Quality in Educational Buildings: A Spanish Case Study

“…Likewise, there is an upward trend in CO2 levels in the period September-December, and then decreases in the period January-May. This trend has a clear explanation in the closing of windows in winter during class time and ventilation between sessions, which contributed to increasing the indoor temperature and thus CO2 levels, since as Zhang et al have established, the human CO2 emission rate increases by approximately 3.5% when the temperature increases by 1 °C [37]. On the other hand, particularly alarming are the maximum values above 1000 ppm reached in the months of November and December, which far exceed the recommended maximum value of 750 ppm indoor concentration.…”

“…For the specific case of this study, it is considered appropriate to use the upper limit of 450 ppm, since the school is located in the central area of the Community of Madrid, being an urban centre with a high population density and vehicle traffic. Likewise, at indoor CO2 concentrations 300 ppm higher than outdoor atmospheric CO2, it is understood that indoor air quality may be compromised and affect student performance [37]. First, Figure 5 shows how the average CO2 value inside the classrooms was higher than 450 ppm in all months.…”

CFD simulation study and experimental analysis of indoor air stratification in an unventilated classroom: A case study in Spain

“…This is attributed to natural buoyancy, which propels warmer, less dense air towards the ceiling. Typically, the relatively elevated temperature beneath the ceiling results in a substantial dissipation of heating energy [ [22] , [23] , [24] , [25] , [26] , [27] ]. This stratification has been described as one of the main causes of energy loss in buildings, so it is very important to take it into account when designing an installation [ [28] , [29] , [30] , [31] , [32] , [33] , [34] ].…”