Get R Value calculations and comparison sheet to find and select most suitable insulation materials for your use. Heat Insulation made of Fire Resistant Insulation Inorganic Mineral Fibers at Wedge India for walls, roofs, tank, foundations, floors cold and hot insulation.
The R-value of insulation materials measures their resistance to heat flow. A higher R-value means better insulating properties. The R-value is calculated based on the material’s thermal conductivity and thickness.
Simplified R-Value Estimation (without k-value):
If you don’t have the thermal conductivity but know the type of insulation and its thickness, you can use typical R-values per inch for that material. For example:
• Fiberglass: ~R-3.2 per inch
• Cellulose: ~R-3.5 per inch
• XPS (Extruded Polystyrene): ~R-5 per inchMultiply the thickness by the typical R-value per inch:
\text{R-value} = \text{R-value per inch} \times \text{thickness (in inches)}
| Insulation Material | R-Value per inch |
| Fiberglass | R-2.9 to R-3.8 |
| Mineral Wool | R-3.3 to R-4.2 |
| Expanded Polystyrene (EPS) | R-3.6 to R-4.2 |
| Extruded Polystyrene (XPS) | R-4.5 to R-5.0 |
| Polyisocyanurate (PIR) | R-6.0 to R-6.5 |
| Closed-Cell Spray Polyurethane Foam (SPF) | R-6.0 to R-7.0 |
| Open-Cell Spray Polyurethane Foam (SPF) | R-3.5 to R-4.0 |
| Cellulose | R-3.2 to R-3.7 |
| Cotton (Denim) | R-3.5 to R-3.7 |
| Aerogel | R-10 to R-30 |
| Vermiculite and Perlite | R-2.0 to R-3.0 |
| Reflective Insulation & Radiant Barriers | Varies (radiant barrier) |
| Sheep’s Wool | R-3.5 |
| Cork | R-3.6 |
| Vacuum Insulated Panels (VIPs) | R-25 to R-30 |
| Calcium Silicate | R-2.7 to R-5.0 |
| Wood Fiber | R-3.5 to R-4.0 |
| Straw Bale | R-1.45 per inch (R-30 to R-35 for full wall) |
Important Notes:
The k-value (thermal conductivity) of materials can vary slightly based on temperature, density, and moisture content.
R-values are often given per inch of thickness, so to increase insulation, you need to increase the thickness of the insulation.
By calculating or estimating the R-value, you can better select insulation materials based on their ability to retain heat (or keep heat out) in various applications.
