Research On The Indoor Thermal Environment Formation Mechanism In Huizhou Traditional Dwellings

To create a comfortable indoor environment is the main development direction of the current architecture based on energy conservation,which has aroused a great interest in developing passive design strategies for traditional vernacular dwellings.Based on the methods of extensive field study,theoretical analysis and energy simulation,typical regions of Huizhou traditional dwellings were selected to investigate the characteristics and formation mechanism of indoor thermal environment.The results from this study can provide some design ideas and theory evidence for the development of Construction of Beautiful Village and green building,which is great helpful for a better inheritance of the Huizhou traditional dwellings.Firstly,the typical regions of Huizhou traditional dwellings were defined,mainly including bedroom,living room and patio.Then,the architectural forms and passive design strategies elements were identified for the three typical regions.Furthermore,the corresponding architectural model was summarized: the single opening model of the bedroom,the double opening model of the living room,the large opening model or multi-opening model of the patio.On the basis of that,the indoor thermal environment formation mechanism was studied for the three typical regions.The bedroom of Huizhou traditional dwellings has the characteristics of cool summer and cold winter through field measurement.The high relative humidity was found to be one of key parameters that affect indoor thermal comfort;and indoor fresh air can meet the need of people health though the bedroom was a single opening model.What’s more,heat loss from the bedroom was found to occur at most time of day in winter according to theoretical analysis.Further study shows that the structural insulation performance and nature ventilation were two major factors affecting the thermal environment.The indoor temperature and speed distribution under different outdoor wind speeds and different levels of internal heat source were investigated using CFD software,and it turned out that indoor ventilation was affected slightly by outdoor wind speed;the indoor internal heat sources can influence indoor thermal environment which can show that with the increase of the indoor auxiliary heat sources,the indoor air temperature in bedroom was also increased.The living room was found to have good thermal insulation during summer but shows a poor indoor environment in winter,while it has a good thermal comfort in spring and autumn.The opening or closing of the front/back door has a significant impact on indoor wind speed.In addition,heat gain is obtained for living room during the daytime while heat loss occur at nighttime in summer,which is mainly caused by nature ventilation.Characteristics of the air distribution is evaluated using the CFD simulation method,the larger the pressure difference between the front and rear door,the more uniform,large volume and performance of the air flow was obtained.Furthermore,the pressure difference between the front and rear door can influence the backflow and vortex in living room,while the magnitude of wind speed affects indoor air age.Since the value of air age in vortex and reflux is larger,it affects the indoor air quality.Patio is considered as a "transition space" of Huizhou traditional dwellings and it plays an important role in regulating indoor thermal environment.According to theoretical analysis,the solar radiation,nature ventilation,building envelope,sky radiation and water evaporation were identified to be the five key items for thermal environment,in which that the nature ventilation is the most prominent.The coupling process between thermal environment and natural ventilation in patio was investigated using Energy Plus/Airflow Network simulation method,and the air change rate,air temperature of patio and the top opening area of patio were found to have a complicated relationship.With the increase of the top opening area of the patio,the air change was also increased,while the air temperature was firstly decreased and then increased.Therefore,the design of patio should be taken into consideration to create a good indoor thermal environment.