The General Council of Technical Architecture of Spain (CGATE) in collaboration with the Polytechnic University of Madrid has published a study on indoor air quality (IAQ) in Spanish homes. To carry out this study, a total of 31 sample homes have been chosen from various regions of the country, in which continuous samples have been taken over a period of 9 days to obtain the concentration of CO2 (main parameter to measure IAQ) in those rooms in which we either spend a greater number of hours or a greater number of people are concentrated, such as living rooms and bedrooms.
In order to establish evaluation criteria for the results obtained, health levels have been considered according to the concentration of CO2 obtained, based on the reference regulations (CTE-DB-HS3, UNE 17133-2:2014 and NTP 549), setting "healthy" CO2 limit values at 900 ppm (parts per million), "unfavourable" above 900 ppm, "worrying" above 1,600 ppm, "serious" above 2,500, and "very serious" if exceeds 5000ppm.
From the data obtained, the study concludes that most of the sampled rooms exceed the "healthy" limit, especially in the bedroom areas, being during the night, when the most unfavourable levels occur, especially if the door is kept closed. the room.
Factors such as the number of people indoor, year of building construction, location, surface, as well as the condition and hermeticity of the windows, have been key when selecting the samples to interpret and assess the results. Likewise, the most affected dwellings, those with a smaller area and higher occupancy density and those with better window closings.
Faced with the data exposed by the study and the evidence on the harmful effects on health of air pollution, the need to promote the construction and rehabilitation of buildings with healthy criteria that improve the well-being and health of users.