Energy and Heat Transfer

Vocabulary flashcards based on lecture notes about energy, heat transfer, and related concepts.

Kilowatt-hour (kWh)

A unit used by energy companies to measure energy; the amount of energy transferred in 1 hour by an appliance with a power of 1 kW.

Payback Time

The time it takes to save the money that an energy-efficient measure costs, calculated by dividing the cost of the change by the saving per year.

Power

The amount of energy transferred per second, measured in watts (W) or kilowatts (kW).

Efficiency

The amount of useful energy transferred compared with the total amount supplied, often expressed as a percentage.

Thermal Conductors

Materials that transfer energy easily through conduction (e.g., metals).

Thermal Insulators

Materials that do not transfer energy easily through conduction; they contain trapped air.

Radiation (Infrared Radiation)

The transfer of energy by waves that don't need a medium to travel through.

Conduction

The transfer of energy through a material via the vibration of particles; most effective in solids.

Convection

The transfer of energy through fluids (liquids and gases) by the movement of heated, less dense fluid.

Internal Energy

The energy stored in the movement of particles within a substance, also known as thermal energy.

Temperature

A measure of how hot or cold an object is, usually measured in degrees Celsius (°C).

Evaporation

A process of transferring energy where the fastest-moving particles in a liquid escape to form a gas, cooling the remaining liquid.