Why Copper Wins Every Race, Heat Transfer, Energy and Expansion, 9289 Phase 2 Unit 303

Right, let me start with the headline back because your tutor's probably already asked you this in the room before you hit play.

Heat moves in exactly three ways.

Conduction, convection and radiation.

That's it.

Every single instance of heat moving anywhere on any job you'll ever do is one of the three or some combination of them.

And here's the one rule that sits underneath all three that's worth locking in before we go any further.

Hot goals cold, not the reverse.

He always moves from a warmer area of an object towards a cool, never the other way round on his own.

Every mechanism we're about to cover is really just a different room.

That same one way journey.

Conduction is heat moving through a solid object from the hot end towards the cold end.

Convection is heat moving through a liquid or a gas.

carried physically by the fluid itself as it circulates, and radiation is heat moving as infrared energy jumping from one object to another without needing anything solid, liquid or gas in between to carry it.

Three different mechanisms, three different situations you'll meet on site.

Let's take them one at a time, starting with the one that decided today's pipe race.

Conduction happens with every single object, as heat energy that's concentrated in one area spreads out towards the cooler areas around it.

At a microscopic level, what actually happens is that the heat energizes the tiny particles that make up the material.

And those particles start to collide with each other.

Each collision passes a bit more of that energy onto the next particle.

and the next, and the next.

And that chain of collisions is what you're seeing as heat traveling up a pipe.

You've lived this one already.

Heat traveling up a copper pipe while you're soldering a joint two feet away.

That's conduction.

That's exactly why you use a wet rag or a heatproof mat near anything you don't want to be cut.

Right, let me start with the headline back because your tutor's probably already asked you this in the room before you hit play.

Heat moves in exactly three ways.

Conduction, convection and radiation.

That's it.

Every single instance of heat moving anywhere on any job you'll ever do is one of the three or some combination of them.

And here's the one rule that sits underneath all three that's worth locking in before we go any further.

Hot goals cold, not the reverse.

He always moves from a warmer area of an object towards a cool, never the other way round on his own.

Every mechanism we're about to cover is really just a different room.

That same one way journey.

Conduction is heat moving through a solid object from the hot end towards the cold end.

Convection is heat moving through a liquid or a gas.

carried physically by the fluid itself as it circulates, and radiation is heat moving as infrared energy jumping from one object to another without needing anything solid, liquid or gas in between to carry it.

Three different mechanisms, three different situations you'll meet on site.

Let's take them one at a time, starting with the one that decided today's pipe race.

Conduction happens with every single object, as heat energy that's concentrated in one area spreads out towards the cooler areas around it.

At a microscopic level, what actually happens is that the heat energizes the tiny particles that make up the material.

And those particles start to collide with each other.

Each collision passes a bit more of that energy onto the next particle.

and the next, and the next.

And that chain of collisions is what you're seeing as heat traveling up a pipe.

You've lived this one already.

Heat traveling up a copper pipe while you're soldering a joint two feet away.

That's conduction.

That's exactly why you use a wet rag or a heatproof mat near anything you don't want to be cut.