Energy

YOU ARE LEARNING:

Reducing Energy Wastage

Despite energy wastage, we can try our best to reduce the amount of energy lost by various means in the real world.

In this lesson, we will be looking at how to avoid wasting energy.

Can you remember what we call it when energy is lost to the surroundings?

Let's first consider an example of why we would like to reduce dissipation.

In winter, we want our houses to be warmer than outside. What kind of energy dissipation do we want to avoid?

Heat can be lost by convection, which is the transfer of energy via gases or liquids. Out of the following options, which do you think might be good ways to reduce convection?

You can select multiple answers

Heat can also be lost by conduction, which is the transfer of energy via solids. Out of the following options, which do you think might be good ways to reduce conduction?

You can select multiple answers

What do you think thermal conductivity means?

Cavity walls are two walls with an air gap between them. Why do you think this might help insulate a house?

We can insulate even better if we fill cavity walls with insulation foam instead of air.

Insulation foam is made of isolated air bubbles. This prevents heat loss by convection as well as conduction!

Which types of windows do you think are better for insulating? "Single" or "double" glazing?

Energy can also be lost when an object experiences resistance, when moving across a solid or through a liquid. Can you remember what we call this?

In order to reduce friction, we can use types of lubrication. For example, we can use grease to fix a squeaky door hinge.

When riding a bicycle, sometimes the friction between the chain and the gear cogs can make it harder to pedal. What do you think we can do to reduce this energy wastage?

We have looked at how thermal insulation can reduce the dissipation of heat energy, and how lubrication can reduce friction.

To prevent heat loss in a house we use materials with low thermal conductivity and seal the house to prevent warm air escaping the house.