In building insulation, industrial equipment insulation, and piping systems, insulation thickness directly affects space occupancy, construction difficulty, and overall energy efficiency. Aerogel and rock wool, as two common insulation materials, have significant differences in their required thickness.

I. Thermal Conductivity Determines the Difference in Base Thickness

The required thickness of insulation materials is essentially determined by their thermal conductivity (λ value).

Aerogel

Temperature conductivity typically ranges from 0.018 to 0.023 W/(m·K)

It is one of the insulation materials with relatively low thermal conductivity currently used in engineering applications.

Rock Wool

Temperature conductivity generally ranges from 0.036 to 0.045 W/(m·K)

It is a traditional and mature inorganic fiber insulation material.

Under the same design thermal performance conditions, the required thickness of rock wool is typically 1.5–2 times that of aerogel.

II. Thickness Comparison for Equivalent Insulation Performance

Taking common industrial or building insulation requirements as an example:

If 10 mm aerogel felt is used to meet the design insulation requirements,

20–30 mm rock wool is typically needed to achieve a similar thermal resistance effect.

This gives aerogel a significant advantage in thin-layer, high-efficiency insulation, especially suitable for applications with limited thickness.

III. Thickness Advantages in Space-Constrained Applications

Insulation layer thickness is often strictly limited in the following applications:

Industrial installations with limited equipment spacing

Petrochemical projects with densely packed pipe racks

Energy-saving renovation projects for existing buildings

Irregularly shaped components such as valves and flanges

Aerogel can achieve effective insulation without significantly increasing the outer diameter, while rock wool often presents the following problems in these applications due to increased thickness:

Spatial conflicts

Increased construction difficulty

Thickening of the outer sheath

IV. Relationship between Thickness and Overall System Performance

Although aerogel has an advantage in thickness, rock wool still has advantages in some aspects:

Rock Wool

Easy to achieve large thickness installations

Stable fire resistance

Suitable for roofs, exterior walls, and large equipment where space requirements are not critical

Aerogel

Thin layers are sufficient to meet insulation needs

Reduces the overall thickness and weight of the system

It helps reduce the burden on supporting and fixing structures.

Therefore, in engineering design, thickness is not the only consideration; it needs to be comprehensively evaluated in conjunction with fire resistance rating, cost control, and the usage environment.

V. Engineering Selection Recommendations

Scenarios where aerogel is preferred:

Space constraints

Significant high temperatures or temperature fluctuations

Equipment and piping with strict dimensional requirements

Scenarios where rock wool is preferred:

Not sensitive to thickness

Requires large-area installation

Focus on a balance between fire resistance, thermal insulation, and cost-effectiveness

From the perspective of insulation thickness, aerogel achieves higher insulation efficiency with a thinner material thickness, showing significant advantages in high-end industrial and special working conditions; while rock wool achieves stable and reliable insulation by increasing thickness, and still has wide application value in conventional building and industrial projects. Reasonable selection of material type and design thickness is key to achieving system energy saving, safety, and economy.