Thermal performance of insulation
The purpose of insulation is to reduce the rate of energy transfer and the effectiveness
of any insulation is determined by its thermal resistance or R-value.
The formula for calculating the Thermal Resistance (R-VALUE) of a product is:
x
R=---
k
R = Thermal Resistance Value (Rval) in m² ºC/W
x = Thickness in meters
k = thermal conductivity in W/mºC
The higher the R-value, the better the insulations performance will be.
What is thermal conductivity?
Thermal conductivity (k-value) is the rate at which heat flows through a unit area
of material, one meter thick if the temperature difference between the two faces
is 1 degree centigrade. Thermal conductivity is dependant on the physical properties
of a material.
Note:
For typical building applications in the South African environment the k-value must
be quoted at a mean temperature of 23 ºC.
Thus:
The lower the k-value and the thicker the material, the higher your thermal resistance
value (R-value) will be and the better the insulation performance.
The energy efficiency of a building involves many factors, but the thermal performance
of the building envelope, including walls, roofs and floors is critical in achieving
thermal comfort.
Insulation assists in protecting your building against cold or heat and provides
an energy efficient environment that is comfortable, healthy and safe.
For more information on thermals visit
www.isover.com