# Which one conducts heat better: water, or air?

If we were to assume room temperature of 20C, which of the fluids conducts heat better, and why?

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Water. By a lot. –  Brandon Enright Jan 30 '14 at 7:06
Which of the fluids? Do you assume pressure high enough for air to be fluid in 20C? –  Andrey Regentov Jun 17 at 9:33

Clicking on the first link in a quick google search for thermal conductivity of common materials takes you to the engineering toolbox. There you will find that the thermal conductivity of air is $0.024\frac{W}{m K}$ and that the thermal conductivity of water is $0.58\frac{W}{m K}$. So, water conducts heat more than twenty times as well as air.