Prefabricated Panel for House Thermal Insulation

The direct use of prefabricated panels for house thermal insulation yields poor results, necessitating secondary treatment or combination with other materials to improve performance. Here is a detailed analysis:

1. Thermal insulation defects of prefabricated panels themselves
Existing prefabricated panel houses generally suffer from poor sound and thermal insulation, particularly prominent in self-built rural houses. The thickness of prefabricated panel floors is typically around 12 centimeters. Although they adopt a hollow structure, the proportion of the hollow part is limited, failing to form an effective thermal insulation layer. Their material (mostly concrete) has a high thermal conductivity coefficient, making them prone to absorbing and conducting outdoor heat in summer, leading to a significant increase in indoor temperature; in winter, due to insufficient thermal insulation, indoor heat dissipates rapidly, creating a 'cold in winter and hot in summer' living environment.

2. Limitations of early application scenarios
In early 20th-century architecture, prefabricated panels were once used as roof thermal insulation layers, but this application needs to be understood in the context of specific historical backgrounds. At that time, buildings had relatively low thermal insulation requirements, and prefabricated panels might have been used in combination with other materials (such as tiles and felt) to form a multi-layer thermal insulation structure. However, modern buildings have significantly higher standards for thermal insulation performance, and relying solely on prefabricated panels can no longer meet the demands, especially under extreme climatic conditions, where their defects become more apparent.

3. Feasible solutions to improve thermal insulation performance
If prefabricated panels need to be used, secondary treatment is required to compensate for their deficiencies:

• Adding a covering layer: Lay high-efficiency thermal insulation materials such as extruded polystyrene boards (XPS) and rock wool boards on the prefabricated panel floors to form a composite thermal insulation layer. These materials have a low thermal conductivity coefficient and can significantly block heat transfer.
• Setting up an air interlayer: Reserve an air layer between the prefabricated panels and the roofing materials, utilizing the low thermal conductivity of air to enhance thermal insulation effects. For example, adopt a double-layer roof structure with air or lightweight thermal insulation materials filled in between.
• Surface reflection treatment: Apply reflective thermal insulation coatings on the outer side of the prefabricated panels to reduce heat absorption by reflecting solar radiation, suitable for areas with high summer temperatures.

4. Alternative solution recommendations
If conditions permit, it is advisable to prioritize the selection of dedicated thermal insulation materials to replace prefabricated panels:

• Cast-in-place foamed concrete: Introduce a large number of closed pores into the concrete through a foaming process to reduce the thermal conductivity coefficient while maintaining structural integrity.
• Composite thermal insulation panels: Use metal-faced sandwich panels (such as those with polyurethane cores), which combine thermal insulation and waterproofing functions, suitable for industrial buildings or temporary housing.

Conclusion: Due to material and structural limitations, prefabricated panels have limited effectiveness when directly used as thermal insulation layers. Their performance needs to be improved through methods such as covering with high-efficiency thermal insulation materials, setting up air interlayers, or applying reflective layers. In modern architecture, it is recommended to select dedicated thermal insulation materials based on specific needs to achieve better energy-saving effects.