Thermal conductivity

Measure of heat flow rate (W/m²) through a material subjected to unit temperature difference (K) across unit thickness (m).

Unit: W/(m.K)

Symbol: \( \lambda \)

Example values

Case Value Source
Air at 300 K and 1 bar 0.0263 W/(m.K) Thermopedia.com :
water at 295 K 0.606 W/(m.K) Thermopedia.com :
Reinforced concrete with 1 to 2% steel 2.3 W/(m.K) Règlementation thermique 2012. Règles Th-U fascicule 2: matériaux :
plywood with density 600 to 700 kg/m³ 0.17 W/(m.K) Règlementation thermique 2012. Règles Th-U fascicule 2: matériaux :