Seasonal Indoor Comfort Evaluation for Residential Retrofitting Assessment

Introduction: Residential retrofit decisions are often guided by predicted energy and comfort performance, yet these predictions may not fully reflect occupants lived experience across different seasons. This study extends earlier work on thermal comfort evaluation by developing an empirical basis for future retrofit visualisation and simulation tools.

Method: Environmental monitoring and occupant surveys were conducted across Adelaide CBD and surrounding areas in Australia during both summer and winter. The study involved 11 dwelling occupants and yielded a total of 60 survey responses. Measured parameters included dry-bulb temperature, globe temperature, air speed, relative humidity, illuminance, and sound level. Occupant surveys captured thermal sensation, thermal preference, overall comfort, lighting satisfaction, acoustic satisfaction, clothing insulation, and activity level. The measured data were processed using the ComfortStat Calculator to estimate Predicted Mean Vote and Predicted Percentage Dissatisfied in accordance with ISO 7730 and ASHRAE Standard 55. These outputs were compared with occupant responses to assess prediction accuracy and identify seasonal differences.

Results: The findings indicate that most occupants reported thermal sensations within the central three categories of the ASHRAE thermal comfort scale, suggesting generally acceptable thermal conditions. When evaluating overall comfort and satisfaction with their indoor environment, respondents predominantly selected “neutral,” “comfortable/satisfied,” or “very comfortable/very satisfied.” In contrast, measurements of the physical indoor environment, including temperature, humidity, and illuminance, revealed spatial variability across different areas of the living spaces, influenced by factors such as room orientation and the presence of openings.

Conclusion: This study provides a calibrated seasonal dataset supporting future retrofit assessment tools. By combining longitudinal environmental measurements with occupant surveys, it establishes a robust framework for evaluating thermal comfort in existing homes. The findings highlight the importance of integrating objective and subjective data to better understand occupant experience and inform retrofit strategies, laying the groundwork for future occupant-centred tools, including potential immersive platforms.