Analysis of occupant satisfaction with IEQ in residential buildings

Multiple studies have shown that occupants’ satisfaction with the indoor environmental quality (IEQ) is not always as high as expected from standards. Furthermore, consensus on methods for quantification of occupant satisfaction is still missing. Therefore, satisfaction assessment and further investigations into the relationships between occupant satisfaction and measured IEQ are needed.

This paper investigated the relationships between satisfaction ratings and IEQ parameters in mechanically ventilated residential buildings. This study used data from Belgian dwellings with a demand-controlled extraction system that was accompanied by a mobile phone application, enabling the users to adapt the ventilation system settings.

In this study, we evaluated the residents’ satisfaction with the IEQ in their main living room. The satisfaction assessment approach consisted of (1) a retrospective survey and (2) the implementation of satisfaction rating scales into the mobile application of the ventilation system, allowing the residents to evaluate their satisfaction with the thermal environment or IAQ. The satisfaction rating option was active for two weeks during winter conditions. Simultaneously, IEQ-related parameters (i.e., air temperature, relative humidity and CO₂ concentration), and residents’ interactions with their ventilation system (e.g., changing airflow rates or CO₂-thresholds) were monitored. We investigated the relationships between the satisfaction ratings and the IEQ- and interaction-related parameters through mixed-effect model analysis.

130 residents filled in the retrospective survey, and over 800 satisfaction ratings were submitted by approximately 60 different dwellings. Results of the retrospective survey and satisfaction ratings show that the participating residents were in general satisfied with the IEQ in their living room. The mixed-model analysis shows that the indoor temperature was the main parameter affecting residents’ satisfaction with both IAQ and thermal environment. Furthermore, the results illustrate that the satisfaction ratings are mostly related to the specific resident, making it challenging to determine an aggregated model without personal and contextual information.