against the transmission of heat
Thermal Conductivity (k-Value)
Thermal conductivity is the time rate of steady-state heat flow through a unit area of a homogeneous material induced by a unit temperature gradient in a direction perpendicular to that unit area, W/m⋅K.
Thermal Resistance (R-Value)
Thermal resistance is the temperature difference, at steady state, between two defined surfaces of a material or construction that induces a unit heat flow rate through a unit area, K⋅m2/W.
Thermal conductance is the time rate of steady state heat flow through a unit area of a material or construction induced by a unit temperature difference between the body surfaces, in W/m2⋅K.
Consequently, the value of the thermal conductance can be calculated by dividing the thermal conductivity with the thickness of the specimen.
R-Value and TOG
Similar to R-value, TOG is a measure of thermal resistance of a unit area, also known as thermal insulance. It is commonly used in the textile industry and often seen quoted on, fibre-filled bedding such as quilts and duvets, and carpet underlay. While engineers use R-values for their heating and cooling energy calculations, TOG is often used when referring to carpet and carpet underlay.
TOG is the R-value x 10. For example: TOG 1.5 = R 0.15 x 10
Thermal insulation for a home is usually a top priority for many families. A standard premium underlay has an average TOG rating of 3.13 and can help reduce an energy bill by up to 15%. The Luxe Collection range of performance underlay increases the average value by a further 13.63%.