Understanding the thermal performance of insulation is imperative when choosing insulation.

**ISOVER`S** impressive array of thermal insulation, in either roll of batts is suited to almost every conceivable application.

Our thermal insulation is second to none offering a wide range of R / lambda values.

**Thermal performance of insulation**

**THERMAL RESISTANCE, (R - VALUE)**

- The ability of a product to resist the transfer of heat
- To calculate the R value you need to know the Thermal Conductivity (K Value) and the thickness of the material being used.

(R value =

__Thickness in meters)__

K Value

Calculation of R-Values for typical Roof/Ceiling Construction Products

- Total R-value of a construction element (Wall or roof) can be obtained by adding the R-values of the different components
- The higher the R value the better the products thermal resistance

**For more information on thermals visit http://www.isover.com**

**THERMAL CONDUCTIVITY, (K / λ - VALUE)**

- All materials conduct heat, some better than others depending on their thermal conductivity. Good insulation materials must have a LOW conductivity.
- Eg. A material with a low conductivity allows heat from one side of a wall to travel very slowly towards the other side of the wall.

- Thermal conductivity is calculated in W/mK (Watts per meter Kelvin degrees). If you test two products with similar densities at the same temperature and one has a K value of 0.040 W/mk and the other has a K value of 0.045 W/mK, the material with the lower K value insulates better which means that the heat will travel slower from a higher temperature to a lower temperature until and equilibrium temperature is reached.
- The ability of a product to conduct heat
- Steel is a good conductor of heat (heat flows faster through steel)
- Wood is a poor conductor (heat flows slower through wood thus making wood a better insulator)

- Calculated in W/m.K (Watts per meter Kelvin degrees)
- K values of typical building materials

- The lower the K value the lower the heat flow through the product