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Science Investigation: Insulation Essay, Research Paper

Science Investigation: InsulationIntroduction My investigation is to

find out the rate of which heat transfer happens. Heat transfer is a process in

which energy in the form of heat energy is exchanged between materials that are

at a different temperature. Heat is generally transferred by conduction,

convection, radiation and evaporation. All of these processes can all happen

simultaneously but it is likely that one will give the greater heat exchange.

Heat is exchanged through the brick wall by conduction. The surfaces of a

high-speed aircraft are heated up by convection. The earth is heated by heat

that is being radiated from the sun.

These experiments involved the temperature of hot water being recorded at

chosen intervals in a copper can.

Here is a description of the following processes that will affect my

experiment:

Conduction

This is where heat energy passes through the walls of the can by making the

particles of the can vibrate and then they will make the particles next to them

vibrate causing the heat to pass through the walls of the can and out to the

surroundings. Materials that are good thermal conductors tend to be good

electrical conductors; metals such as gold, silver and copper have high thermal

conductivity’s and will conduct heat readily. Materials such as glass have much

smaller heat transfer values and are poor heat conductors.

Convection

This is where the cooler water particles sink down to the bottom and the warmer

water particles float up to the top. Convection will only affect my experiment

if I did not have a lid. This is because the warm water will float up to the

top and the heat energy will escape out of the top. If a pan of water was being

heated from below then the water particles at the bottom of the pan will become

warm as therefore become less dense, they will begin to rise to the top of the

pan. As the warmer water particles begin to rise, the cooler water particles at

the top of the pan will sink to the bottom, as they are less dense. Once at the

bottom of the pan the will start to get warmer and become less dense. This

process will continue until the pan of water is at the same temperature.

Radiation

This is when the warm water particles vibrate the water particles next to them.

This will give them more energy and will make the water there warmer. The water

particles at the top of the can will radiate the heat energy into the

surrounding air. For heat to radiate it does not need to be in contact with

matter. Heat can radiate for some thing to another body through a complete

vacuum, this is how the sun heats up the earth. This process can also be called

the Wave Motion.

Evaporation

This could cool down the water, as when the water evaporates it will take the

heat away with it in the same way evaporating sweat cools down our bodies. If I

use a lid this could slow down this process. As the water vapour will not be

able to escape into the air as quickly as it would normally keeping the heat in

for longer.

If I insulate the can with different materials then it will slow down the heat

loss, but I cannot stop it. This will be useful for keeping drinks hot.

The materials that I could insulate the copper can that I will be using for my

experiment are:

Black paper

Corrugated card

Cotton wool

Tin foil

I also conducted my experiment without any insulation so I can compare the

results between insulated and non-insulated to find out if there is a distinct

difference in heat loss.Question to investigate What material/s offer the best protection against the cold, or, which material/s

is/are are the best insulators.Aim The aim of this investigation is to test three materials (wool, bubble

wrap, plain copper), and see which one/s are the best at keeping in the heat of

the hot water in the copper container.Factors There are many factors, which can affect

my experiment. The factors are:

If a lid is used, there will be a great difference in the speed of heat loss if

I use a lid. This is because a large amount of heat will escape form the top of

the container by convection and evaporation. Therefore if I use a lid it will

slow down these processes.

Also what the lid is made of will make a difference. If a lid is made of paper

or card then its insulation properties will be at a minimum, however if the

material used for a lid is polystyrene or bubble wrap then the heat loss

through the top of the container will slow down.Volume of water used When the volume of water is

higher, it will stay warmer for longer than if there was a low volume of water.

This is because when there is a high volume of water then the outside of the

water will cool down, but the inside will stay warm.If the container that the

water is insulated then it will stay warmer then if the container is not

insulated. This is because the insulation will slow down the process of heat

loss. If the container does not have insulation then the process will not slow

down.

If different types of insulation are used then this will affect the heat loss.

Materials of high insulation such as bubble wrap or cotton wool will not allow

much heat to be transferred through it, however materials of low insulation

such as black card will let the heat pass through it

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