Convection - A Second Mode of Heat Transfer

Hello team at Easy Plumbing Knowledge! In previous post we have learned a lot about heat transfer and in the very last post we focused on conduction as one of the types of heat transferred. We learned that conduction has to do with heat transfer between solid objects. 

In today's post we will learn about a second mode of heat transfer: convection. In convection, heat transfer occurs when a gas or a liquid moves along a surface. Of course, for the heat transfer to occur, the liquid or gas is at a different temperature than that of the surface. 

One important fact to notice about convection is that the speed that the fluid (gas or liquid) moves at while touching the surface influences the rate of the heat transfer. This is why when you feel a burst of air, you feel refreshed in a hot day. The speed of the gas as it touches your skin increases the rate at which heat transfer from your skin to the air.

In heating system, there is two types of convection used. One of them is natural convection, which does not use a blower to force air. This type of convection is usually seen with finned-tubed baseboard heat emitters in which heat is transferred to the surrounding air naturally. In contrast, there is heat emitters that use fans or blowers to force air that goes through a coil which transfers the heat to the air that comes in at speed.