Linear, non-linear and alternative algorithms in the correlation of IEQ factors with Global Comfort - A Case study

Indoor environmental quality (IEQ) factors usually considered in engineering studies, i.e., thermal, acoustical, visual comfort and indoor air quality are individually associated with the occupant satisfaction level on the basis of well-established relationships. On the other hand, the full understanding of how single IEQ factors contribute and interact to determine the overall occupant satisfaction (global comfort) is currently an open field of research. The lack of a shared approach in treating the subject depends on many aspects: absence of established protocols for the collection of subjective and objective measurements, the amount of variables to consider and in general the complexity of the technical issues involved. This case study is aimed to perform a comparison between some of the models available, studying the results of a survey conducted with objective and subjective method on a classroom within University of Roma TRE premises. Different models are fitted on the same measured values, allowing comparison between different weighting schemes between IEQ categories obtained with different methods. The critical issues, like differences in the weighting scheme obtained with different IEQ models and the variability of the weighting scheme with respect to the time of exposure of the users in the building, identified during this small scale comfort assessment study, provide the basis for a survey activity on a larger scale, basis for the development of an improved IEQ assessment method.