Indoor environmental quality models: A bibliometric, mapping and clustering review

Indoor environmental quality (IEQ) plays an essential role within buildings, impacting health, well-being and productivity, considering that individuals spend much of their daily lives indoors. Providing these individuals with a comfortable environment is an important issue. Through a literature review in the Scopus database, one thousand seven hundred and ten articles were identified, of which seventy-eight were selected based on the criteria established. Then, studies on IEQ models were investigated using bibliometric, mapping and hierarchical cluster analysis. The main conclusions of this research are: (I) bibliometric analysis revealed the existence of ninety-five indoor environmental quality models; (II) twelve aspects were identified: tangible aspects (usually measured by an equipment), encompassing thermal comfort, indoor air quality, acoustic comfort and visual comfort; and intangible aspects (mainly obtained by subjective responses via questionnaire), including biophilia and exterior views, cleaning and maintenance, personal control, layout and furniture, location and amenities, colors and textures, friendly atmosphere and pleasure at work; (III) mapping analysis revealed that the indoor air quality aspect is predominant in the models selected; (IV) hierarchical clustering formed five clusters, grouping the aspects thermal comfort and indoor air quality aspects in the same cluster; (V) the visualization of models highlighted the multidisciplinary nature of the indoor environmental quality concept, comprising physiological, psychological and social aspects. These results contributed to verifying the current state of the art and identifying future trends, highlighting a gap related to intangible aspects in the models. Also, improving IEQ by considering occupant behavior can help reduce energy consumption inside buildings.