Question

Why do the steam pipes that carry steam at 100 °C warm buildings more effectively than water pipes that carry water at 100 °C?

Answer 1

1. When heat is supplied to water, its temperature rises.
2. After attaining the temperature of 100 °C, on further supplying heat, its temperature does not rise further.
3. Instead, the kinetic energy of the water molecules increases and it gradually converts into steam.
4. The specific latent heat of vaporization is the amount of heat energy required to change the unit mass of water at 100 °C into steam at 100 °C. Its value is 226 x 10⁴ J kg^-1.
5. Hence, steam at 100 °C has more heat energy when compared to water at 100 °C, since the heat is being stored as latent heat in steam.
6. So, the steam pipes that carry steam at 100 °C warm buildings more effectively than water pipes that carry water at 100 °C.