§3 Insulating part 2

• Natuurkunde
• Middelbare school
• havo
• Leerjaar 3

Today: 

• Recap last session
• Discussing assignments (4,5)
• Calculating heat flow through a wall
• Homework

Recap: what can you tell about...

- Convection

- Conduction

- Radiation

Heat transport

A process by which heat is moved from warm areas to cold ones.

What isn't a conductor?

1. aluminium
2. iron
3. plastic
4. copper

In which type of heat transport is no substance needed?

1. relocation
2. conduction
3. convection
4. radiation

How is heat conducted when an ice cube is in your hand?

1. From the ice cube to your hand
2. From your hand to the ice cube

Opdracht 4

Why does ice not thicken despite severe frost when there is snow on it?

Wall insulation

A building conducts heat relatively well, which means that a lot of the heat from a house can dissappear outside. How much heat flows outside through a wall per second depends on: 

• Temperature difference 
• Surface area of the wall
• Quality of the insulation

Q​w​​=U⋅A⋅ΔT

Q_w = heat loss per second (J/s)

U = the U value of the wall (W/(m² *         )

A= the surface area of the wall (m² )

delta T= temperature difference between outdoors and indoors

(         )

Q​w​​=U⋅A⋅ΔT

°C

°C

Assignments

7+9