Is Prefabricated House Warm in Winter and Cool in Summer?
Prefabricated houses generally do not possess the characteristic of being warm in winter and cool in summer. This is elaborated from two aspects: historical examples and regulatory requirements.
From historical examples, the prefabricated panel houses widely used in the 1970s and 1980s had significant defects in thermal insulation performance. The walls and floors of these houses were mostly assembled from prefabricated concrete components. The materials themselves had high thermal conductivity, and there were gaps at the joints, leading to frequent heat exchange between the indoors and outdoors. In winter, indoor heat rapidly dissipated to the outdoors through the walls and floors. Even with heating equipment turned on, it was difficult to maintain a comfortable temperature, often resulting in a small temperature difference between indoors and outdoors. Some residents even described the indoor environment in winter as 'cold as an ice cellar'. In summer, the opposite occurred. High outdoor temperatures were conducted indoors through the walls, and with insufficient ventilation design and poor air circulation, the indoor environment became unbearably hot, creating a 'sauna effect'. This issue of being 'cold in winter and hot in summer' was closely related to the low production technology of prefabricated components and building energy efficiency standards at that time.
From the perspective of regulatory requirements, the 'Basic Safety Technical Guidelines for Rural Dangerous House Renovation' issued by the Ministry of Housing and Urban-Rural Development explicitly emphasizes that house renovation should focus on 'building energy efficiency' and 'livability'. Among them, 'building energy efficiency' requires measures such as optimizing wall materials, adding insulation layers, and improving door and window sealing to reduce heat transfer efficiency. 'Livability' requires that indoor environmental indicators such as temperature, humidity, and ventilation meet human comfort needs. However, due to structural limitations, traditional prefabricated panel houses are difficult to meet these requirements through simple repairs. For example, if an insulation layer is added to the original walls, considerations such as component load-bearing capacity, construction feasibility, and cost need to be taken into account. If ventilation is to be improved, the positions of doors and windows need to be redesigned or additional vents need to be added, which may damage the overall structure of the house. Therefore, the defects of being 'cold in winter and hot in summer' are difficult to completely solve through local renovations.
In conclusion, the performance of prefabricated houses in terms of being warm in winter and cool in summer is limited by materials, structure, and design standards. Traditional prefabricated panel houses, in particular, have significant shortcomings. To improve their thermal comfort, comprehensive improvements need to be made in multiple aspects such as material upgrading, structural optimization, and energy-efficient design.
