And Thats it!

This project was submitted by:
Niall Canavan, Daragh O'Leary, Leona Douglas

MEASUREMENT OF THE SPECIFIC LATENT HEAT OF FUSION OF ICE

MEASUREMENT OF THE SPECIFIC HEAT CAPACITY OF WATER

Heat Transfer

Three methods of Heat Transfer:         1. Conduction              2. Convection              3. Radiation

1. Conduction is the movement of heat energy through a substance by the passing on of molecular vibration from molecule to molecule, without any overall movement of the substance.

You are expected to be able to demonstrate how to compare rates of conduction through different solids (Junior Cert)

U-Value

U-Values are used in domestic situations to give an indication of how well a substance (roof, walls, tiles, etc) allows heat to flow (conduct) through it.

U-Values are a measure of the conductivity of a substance, i.e. a structure that is a good insulator has a low U-Value.

The U-Value of a structure is the amount of heat energy conducted per second through 1 square metre of that structure when a temperature difference of 1⁰ C is maintained between its ends.

2. Convection is the transfer of heat through a fluid by means of circulating currents of fluid caused by the heat.

Because hot water expands, it is less dense than cooler water and so rises.

This principle is used in domestic hot water and heating systems.

3. Radiation is the transfer of heat energy from one place to another in the form of electromagnetic waves.

The Heat Pump

The Heat Pump is a device that extracts available heat from one area and transfers it to another to either heat or cool an interior space.


Examples: 1. Refrigerator* 2. Perspiration*.

Latent Heat

Storage Heaters

·         In an electric storage heater, bricks with a high specific heat capacity are heated overnight by passing an electric current through a heating coil in the bricks. The bricks are surrounded by insulation.

·         The bricks are heated by night when electricity is cheaper.

·         The system is closed in but has a cover which can be opened to release the heat when needed.

·         During the day the bricks slowly give out their heat, thus heating the room.

·         Because the bricks have a high specific heat capacity they can absorb a lot of heat without increasing very much in temperature, therefore not losing much back to the environment.

                                                          

                                                    eg. Radiator