Thermal Insulation, Efficiency, and Energy Resources

This set of vocabulary flashcards covers thermal energy transfer mechanisms, insulation methods, efficiency calculations, and the characteristics of renewable and non-renewable energy resources based on the lecture transcript.

Conduction

The process where vibrating particles transfer energy to neighbouring particles, occurring mainly in solids.

Convection

The process where energetic particles move away from hotter to cooler regions, occurring in liquids and gases.

Thermal conductivity

A measure of how quickly energy is transferred through a material.

Loft insulation

A method to reduce convection by trapping air in little pockets between fibres to reduce air flow.

Cavity walls

Walls made up of an inner and outer wall with an air gap in the middle to reduce energy transfer by conduction.

Cavity wall insulation

A foam used to fill the air gap in cavity walls to reduce energy transfer by convection.

Double-glazed windows

Windows with an air gap between two sheets of glass to reduce energy transfer by conduction.

Draught excluders

Devices placed around doors and windows to reduce energy transfers by convection.

Lubricants

Usually liquids like oil that flow easily between objects to coat them and reduce friction between surfaces.

Efficiency

The proportion of total input energy or power that is transferred usefully.

Efficiency (Energy Equation)

$$\text{Efficiency} = \frac{\text{Useful output energy transfer}}{\text{Total input energy transfer}}$$

Efficiency (Power Equation)

$$\text{Efficiency} = \frac{\text{Useful power output}}{\text{Total power input}}$$

Non-renewable energy resources

Fossil fuels and nuclear fuel (uranium and plutonium) that will one day run out.

Fossil fuels

Natural resources formed underground over millions of years, including coal, oil, and (natural) gas.

Renewable energy resources

Resources that will never run out, including the Sun, wind, water waves, hydro-electricity, bio-fuel, tides, and geothermal.

Geothermal heat pump

A system that uses geothermal energy resources to heat buildings.

Solar water heaters

Devices that use the Sun to heat water which is then pumped into radiators in a building.

Wind turbines

Devices containing a generator that uses rotating blades to produce electricity in exposed places.

Solar cells

Devices used to generate electricity directly from sunlight, often used in remote places or to power small electronics like calculators.

Geothermal power

Energy sourced from underground thermal energy stores, originating from the slow decay of radioactive elements like uranium inside the Earth.