Adaptive Thermal Comfort in Residential Buildings, A Case Study of Wuhan

As an innovative approach to achieve energy conservation and sustainable building development, studies of adaptive thermal comfort have been widely recognized in the recent years. Contextual variations in the living environments shape the diversity of occupants' adaptive thermal comfort and therefore more in-depth localized investigations are required, and this is true of current China. During the rapid urbanization process, many uncertainties still exist around residents' adaptive thermal comfort in terms of its adaptation process and underlying adaptively comfortable thermal boundaries which will contribute to housing energy conservation. This study addresses the above problems through investigation in residential buildings using the case of Wuhan, a typical city in the Hot-Summer and Cold-Winter climatic zone of China.;Field surveys and associated statistical analysis were employed as the main research methods for this study. The survey investigated 428 urban households to characterize their daily thermal behaviours and thermal requirements through questionnaires. Meanwhile, 513 sets of thermal comfort data draw from 71 households (in naturally ventilated buildings) reported residents' real thermal perception corresponding Hot-Summer and Cold-Winter climate. Longitudinal investigation on several families also was conducted to further explain some relevant non-climatic impacts.;This study reveals that local residents autonomously adapt themselves well to the local climate though all kinds of convenient and simple adjustments, such as dressing-habits, control of windows and doors, food and drink intake, intermittent and local heating/cooling pattern, and lower thermal expectation. In the naturally ventilated residential buildings, the measured indoor thermal environments were very hot-humid in summer and cold-damp in winter, and were highly associated with outdoor climate. Occupants reported general acceptance and comfort in those conditions but would have preferred to be cooler in summer and warmer in winter. Meanwhile, based on the whole-year data, local residents' thermal perception including thermal sensation, thermal comfort, thermal preference and thermal acceptability, changes remarkably with the physical thermal variations; while this change rate is much lower in the respective seasons, so demonstrating the identified thermal adaptation. Longitudinal case studies indicate non-thermal factors including housing characteristics, consumer-values and living habits influence residents' adaptive thermal comfort significantly in addition to the climatic impacts.;Based on the comparisons between this study's results and others' previous work, for the residential buildings under local climatic conditions, the author suggests that adaptive model is represented as " Tn=0.6*Tout+9.8 " and the associated acceptable operative temperature range is from 14°C to 27°C with the approximate relative humidity range of "10%∼87%". The limitations and potential improvements of the conventional thermal indices "PMV-PPD" and "SET" when they are employed to predict adaptive thermal comfort are also discussed. Finally, the study suggests that "adaptive thermal comfort" should be encouraged as the thermal environment design goal rather than "static thermal comfort" in the China urban housing context.;The significance of this study is to provide an implementable adaptation model and acceptable temperature and humidity range for the residential buildings under local climate conditions, and to provide a broader database for general adaptive thermal comfort studies in terms of its adaptation process, extension of existing thermal indices for adaptive thermal comfort and adaptive opportunities creation in buildings.