The Effect of Different Types of Insulation on Heat Retention
I am going to investigate the effect of different types of material on
heat retention. "Which of the four materials, cotton, foam, aluminium
foil and bubble wrap, is the best insulator?"
The four materials tested in this experiment are cotton, foam,
aluminium foil, and bubble wrap. Materials that are good insulators
will absorb heat
slowly and therefore the water inside the cup will
stay warm for a longer period of time. Materials vary in their heat
conductivity and in their insulation
capacity. Foam is 95 percent air
so the air molecules slow down the heat transfer from the liquid, so
it stays warmer longer than cotton insulation. This leads me to
predict that foam would be the best insulator, as it would trap the
heat more, which will cause deficient heat lost.
Identification of Variables
There are three variables I will take in consideration whilst carrying
out my investigation. The independent variable will be the types of
materials used for insulation, which will be cotton, newspaper,
aluminium foil, and black insulator. My control variables would be the
temperature of the water, 80° Celsius. The dependent variable in my
investigation will be the amount of heat loss.
The different types of energy transfers that will be taking place
during this experiment will be conduction, convection, insulation, and
radiation. Heat is transferred from one material to another through
conduction. That happens when the water comes into contact with the
cup itself. Materials that are good at conducting heat absorb the heat
of the liquid quickly, and therefore, the liquid cools down. This
happens when the heat energy is transferred from the water to the cup
and then from the cup to the material around it. If the material is a
good conductor, the heat absorbed would be faster so the heat loss
from the water itself would increase as well. Insulation reduces heat
loss and the rate of cooling. Absorption of heat is slower in
materials that are good insulators so the water inside the cup stays
warm for a longer period of time. Insulation is the restriction of
heat. Insulation is also the material used to cause these
restrictions. Insulation is used in houses to keep the heat inside
during the winter and outside during hot times. Insulation is also
used in blankets, jackets, and drink bottles. Insulation does not
create heat; it prevents heat from flowing. Therefore, if you placed a
blanket over something cold, it will be cold underneath the blanket.
Materials differ in heat conductivity and so also vary in their
insulation capacity. When the water will be heated, it will move
upwards as a result of the heat. Warm air will rise and cool air will
fall. So convection would be taking place. Then this thermal energy
will transfer to the material around the hot water bottle as thermal
energy flows from warmer
objects to cooler objects. This will cause the material around the
water bottle to either absorb energy or to reflect it. Throughout all
of these processes radiation would be taking place as the heat would
be transferred as energy by particles which will then depending upon
the material will either be absorbed or reflected.
1 piece of cotton
1 piece of foam
1 sheet of aluminium foil
1 bubble wrap
4 Cups with lids
10 rubber bands
1 piece of play-do
Health and Safety Limitations
· Tie back hair while carrying out the experiment
· Throughout the experiment, wear goggles
· Handle the hot water very cautiously
· Do not put the cups filled with hot water at the edge of the table.
· Prepare water baths at 80°C.
· Take four cups with lids on each one of them and take one more cup
without a lid as this is going to be the control for comparison.
· Cover one of the cups with one layer of cotton.
· Fix the fabric on the bottle with the help of rubber bands.
· Pierce the lid, with a thermometer, and fix it to the cap with
· Repeat # 3, 4, and 5 with foam, aluminium foil, and bubble wrap and
prepare a "control" without a fabric.
· Measure 200 ml of water in 5 different beakers and pour them into
the cups simultaneously with the help of a funnel.
· Immediately put the cap back on with the thermometer. (Don't use the
same thermometer for all experiments)
· All five specimens must be carried out concurrently for it to be a
· Record the temperature from the thermometer every five minutes till
40 minutes have passed (make sure you use a stopwatch for the time).
· Record your results in a table and present them on a graph.
Type of material
In conclusion, out of the materials, aluminium foil, foam, cotton, and
bubble wrap, aluminium foil is the best insulator as it restricts the
transfer of heat so it slows it down and it reflects the heat energy.
The statistics above indicate that the best insulator is aluminium
foil. By examining the results, I can competently say that the rate of
heat loss for aluminium foil was very slow. Consequently, it kept
water hot for the longest period of time, as the heat absorption
occurring was gradual as well. Aluminium is a metal; metals are good
conductors of heat and electricity, which means that they transfer
energy from one particle to another. This is known as the collision
theory. However, because aluminium is a shiny metal, it reflects more
heat than it absorbs heat which may have caused the reduction of heat
. The results also indicate that my prognostication at the
start was miscalculated or was effected by some incorrect procedures
during the experiment. Compared to the control, aluminium foil is a
better insulator, which shows that it would absorb heat slower than a
normal cup with water, would do.
Bubble wrap is the second best insulator as it contains air pockets,
which either traps or slows down the heat energy, as it is radiated
from the water into the air molecules. As the heat energy is slowed
down, so is the rate of heat retention because the energy through the
particles is moving very slowly. When compared to the control, bubble
wrap is a better insulator because of the trapping of heat energy
inside the air pockets, so the water stays warmer with the bubble wrap
on then no material around the cup at all.
The material, foam, which I prophesied, is the third best insulator as
it is 95 percent air so air molecules from the liquid slow the heat
transfer down, so it remains warmer, longer than cotton insulation.
Since the heat transfer is slowed down by the air molecules, the
process of heat absorption is also slowed down so by the time heat
energy gets to the foam, it is so slow that very less of it can be
absorbed. Foam is a good insulator but when it is compared to the
control, it is not as good at insulating as the cup without any
Furthermore, my results show that the cotton is the worst insulator
out of all the materials. This maybe because it cannot cause the
restriction of heat. It may, however, be a good conductor as it is
absorbing heat very quickly as the particles are transferring heat
energy at a very fast rate. Even though it is the worst insulator out
of the materials I used in this experiment, compared to the control,
which had no material around it, the temperature loss is very close to
each other. The temperature in both the cotton and no material is
decreasing by either 3 or 4 degrees. So in reality, cotton may act as
an insulator but it will not keep either things or people warm for a
very long period of time. Even though, the cup without any material is
a better insulator than the cotton-insulated cup.
I think that during my experiment, some things went wrong which made
my results less reliable. The temperatures recorded for all specimens
were too close because they were measured by a thermometer. In future
when I repeat this experiment again, I would use temperature censors
to obtain more reliable and accurate results. Also I would repeat the
experiment three more times for it to be a fair test. Then I would
take an average of the results. Another factor that might have changed
the results slightly was that I did not cover the cup completely from
top to bottom so some parts of it were still exposed to cold air of
the air conditioning. Also the cups had some tiny holes which I did
not cover with play do until half way between the experiment. So for
next time, I will need to cover the whole cup rather than just around
the cup. One of the other reasons that also caused problem in the
results was that all the cups were made out of cardboard which might
have contributed to slowing down the heat loss. Undertaking this for
next time, I would carry out my experiment in tin cans as they conduct
heat rather than insulating heat so it would not affect my results.
The biggest factor for the inaccurate results was that the lids of all
the cups (except the control as it did not have one). All cups were
made out of plastic and plastic is a good insulator so along with the
cardboard, plastic played a major role in reducing the heat loss from
all the cups. So for my future reference in doing this same
experiment, I will not perform the same mistakes again in order to
obtain better, more reliable and accurate results.