In building energy conservation, industrial insulation, and equipment piping systems, the thickness design of insulation materials directly affects the system's energy-saving effect, construction space occupation, and overall operating costs. Rubber-plastic insulation materials and aerogels, as two widely used insulation materials, differ significantly in thermal conductivity and structural characteristics, which determines their different thickness requirements in practical engineering. This article will systematically analyze the differences in thickness requirements between rubber-plastic and aerogels from the perspectives of material properties, thermal conductivity, and application scenarios to help engineers make more reasonable judgments during the selection phase.

I. Differences in Material Properties between Rubber-Plastic and Aerogels

1. Basic Characteristics of Rubber-Plastic Insulation Materials

Rubber-plastic insulation materials typically use synthetic rubber as the main raw material, forming a closed-cell structure through a foaming process. This structure effectively prevents water vapor penetration, possesses good anti-condensation performance, and has a certain degree of flexibility, making it widely used in HVAC ducts, chilled water systems, and other fields.

The advantages of rubber-plastic materials lie in their ease of construction and strong adaptability, but their thermal conductivity is relatively high. Therefore, to achieve the same insulation effect, a higher material thickness is required. 2. Basic Characteristics of Aerogel Insulation Materials

Aerogel is a novel high-performance insulation material with a nanoscale porous structure filled with air, significantly suppressing heat conduction. Aerogel is renowned for its ultra-low thermal conductivity and is one of the best-performing solid insulation materials currently commercially available.

Due to its unique microstructure, aerogel requires a significantly smaller thickness than traditional insulation materials to achieve the same insulation effect.

II. The Influence of Thermal Conductivity on Thickness Requirements

1. Relationship between Thermal Conductivity and Thickness of Rubber-Plastic Materials

The thermal conductivity of rubber-plastic insulation materials is typically between 0.032 and 0.038 W/(m·K). In low-temperature or high-condensity conditions, a thicker rubber-plastic layer is often required to meet design standards and reduce heat loss.

In some chilled water or refrigerant piping systems, the thickness of the rubber-plastic insulation layer is typically 20–40 mm or even higher to meet long-term energy-saving and anti-condensation requirements. 2. Advantages of Aerogel Materials in Thermal Conductivity

The thermal conductivity of aerogels is typically as low as 0.018–0.023 W/(m·K), far lower than that of rubber and plastic materials. This means that, while achieving the same insulation performance, the required material thickness for aerogel can be significantly reduced.

Under the same operating conditions, the thickness of an aerogel insulation layer is often only 1/3–1/2, or even less, that of rubber and plastic materials.

III. Comparative Analysis of Thickness Requirements in Actual Engineering Projects

1. Thickness Differences in Pipe Insulation Systems

In pipe insulation applications, space is often limited by the layout of supports, valves, and equipment.

When using rubber and plastic materials, a larger installation space is required to meet the necessary insulation thickness;

When using aerogel materials, the same or even higher insulation effect can be achieved within a limited space.

Therefore, in space-constrained pipe systems, aerogels have a greater advantage in thickness control.

2. Differences in Insulation for Equipment and Irregularly Shaped Structures

For insulation of equipment surfaces or irregularly shaped structures, the cutability and thickness control of materials are particularly critical.

Wrapping complex structures with thick rubber and plastic materials presents certain difficulties.

Aerogel materials, due to their thinner thickness, are easier to adhere to complex surfaces, reducing thermal bridging.

IV. Comprehensive Impacts of Thickness Differences

1. Impact on Construction and Space

The greater thickness of rubber and plastic materials occupies more space, potentially increasing construction difficulty in areas with dense equipment or limited ceiling height. Aerogel, on the other hand, effectively reduces the overall volume of the insulation system, facilitating system integration.

2. Impact on Energy Efficiency

Provided the design thickness meets requirements, both can achieve the insulation target. However, under thickness constraints, aerogel can still maintain good thermal insulation performance, while insufficient thickness of rubber and plastic materials may lead to increased energy consumption.

3. Impact on Costs

From an initial investment perspective, rubber and plastic materials have lower costs, but due to the greater thickness requirements, material usage and space costs increase. While aerogel has a higher unit price, its thinness and high efficiency make it a more economical option in some projects.

V. Thickness Selection Recommendations for Different Application Scenarios

| Application Scenarios | Rubber and Plastic Materials | Aerogel |

| ------- | --------- | --------- |

| Conventional HVAC Piping | ✔ Applicable | △ Optional |

| Space-Constrained Piping | △ Constrained | ✔ Preferred |

| Projects with High Energy Efficiency Requirements | △ General | ✔ Preferred |

| Insulation of Irregularly Shaped Equipment | △ General | ✔ Preferred |

| Cost-Sensitive Projects | ✔ Preferred | △ Higher |

In summary, the difference in thickness requirements between rubber and plastic materials and aerogel mainly stems from the fundamental differences in their thermal conductivity and material structure. Rubber and plastic materials require increased thickness to achieve insulation effects, while aerogels, relying on their ultra-low thermal conductivity, can meet high insulation standards even with a thinner layer.

In practical engineering selection, space conditions, energy-saving goals, and project budget should be comprehensively considered to rationally choose either rubber/plastic or aerogel insulation materials, achieving the best balance between performance and cost.