Picture the Sun and the Earth with arrows traveling from the Sun to the Earth through space. The arrows represent the energy that travels to the Earth via radiation, which does not require any medium atoms or molecules to do so.
First, identify the type of home heat loss pictured in images A-J as either: conduction, convection or radiation. Then click and drag each image down to the correct category at the bottom of the screen.
Identify the type of heat loss conduction, convection, or radiation for each of the following examples:. Skip to main content. Mechanisms of Heat Loss or Transfer Print Heat escapes or transfers from inside to outside high temperature to low temperature by three mechanisms either individually or in combination from a home: Conduction Convection Radiation Examples of Heat Transfer by Conduction, Convection, and Radiation.
Conduction : heat moving through walls of a home from high temperature inside to low temperature outside. Convection : heat circulating within the rooms of a house. Radiation : Heat from the sun entering a home. Click here to open a text description of the Conduction Candle animation.
Example of Conduction A hand holds a metal rod above a lit candle. Click here to open a text description of Conduction in Regard to Residential Heating example. Example of Conduction in Regard to Residential Heating Picture the cross section of a wall in a house.
Click here to open a text description of the Convection Candle animation. Example of Convection A hand is held above a lit candle. Click here to open a text description of the Convection in a Room animation. Example of Convection in Regard to Residential Heating Picture a room with an open door letting in cool air on the left and a radiator creating heat on the right. Click here to open a text description of the Radiation Example animation.
Click here to open a text description of the Test Yourself activity. Test Yourself: Types of Heat Loss Identify the type of heat loss conduction, convection, or radiation for each of the following examples: Heat escaping through the roof of a house A hot stove burner Boiling water A torch halogen lamp producing light and heat A door hanging wide open, letting in cold air A fire creating heat Heat escaping through a wall A mirror reflecting sunlight Heat escaping through a window Heat escaping through a chimney Answers: A.
As heat energy flows from the hot object to the cold object, the heat energy from your hot water will be transferred to the surrounding cold air inside the fridge once you put the glass jars inside. The most significant mechanism of heat transfer in this case is convection, which means that the air just next to the hot jar is warmed up by the hot water.
Then, the warm air is replaced with cold air, which is also warmed up. At the same time, the cold air cools down the water inside the jar. The heat of the hot water is transported away by the flow of cold air around the cup.
If you left the jars in the fridge long enough, you might have observed that the temperature changes until the hot water reaches the temperature inside the fridge. Without a temperature difference between the water and the fridge, the heat transfer will stop. Heat from the water is also lost through conduction: the transfer of heat through the material, which is dependent on the thermal conductivity of the material itself.
The glass jar can conduct heat relatively well. You notice that when you touch the glass jar with the hot water the glass feels hot as well. What effect did the different wrapping materials have?
You should have noticed that with wrapping materials, the temperature of the water after 10 minutes inside the fridge was higher compared to the unwrapped control. Wrapping the glass jar reduces the heat transfer from the hot water to the cold air inside the fridge. Using wrapping materials that have a very low thermal conductivity reduces the heat loss through conduction. At the same time the insulator can also disrupt or reduce the flow of cold air around the glass jar, which results in less heat loss via convection.
One way of reducing convection is creating air pockets around the jar, for example, by using insulators such as bubble wrap, fabric or wool, which have a lot of air pockets. Air in general is a good thermal insulator, but it can transmit heat through convection. However, if the air pockets inside the insulating material are separated from each other, heat flow from one air pocket to another cannot happen easily. This is the reason why you should have measured the highest temperature in the bubble-wrapped jar and fabric-wrapped jar.
This also explains why most of our clothes are made of fabrics and why you stay warmer when you put on an extra jacket. Paper and foil make it easier for the heat to escape because they don't have many air pockets. This activity brought to you in partnership with Science Buddies.
Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. Discover World-Changing Science. Key concepts Physics Heat transfer Insulation Material science Introduction What do you do when it gets very cold in winter? Materials Five glass jars with lids Scissors and adult to help with cutting Tape Aluminum foil Bubble wrap Wool scarf or other wool clothes Paper Hot tap water Thermometer Fridge Timer Paper for writing Pen or pencil Preparation Cut a piece of the aluminum foil, the bubble wrap and the paper have an adult help if necessary.
Each piece should be large enough to fit three times around the sides of the glass jar. Take the piece of aluminum foil and wrap it around the sides of one of the jars. You should have three layers of foil around the glass jar. Use the tape to attach the foil to the jar. Next, wrap another jar with the bubble wrap so that the glass is also covered in three layers.
Make sure to tape the bubble wrap onto the jar. Use the cut paper to wrap a third jar in three layers of paper. Once again, attach the paper to the glass jar. Take another glass jar and wrap the scarf or other wool fabric around the jar. Only make three layers of wrapping and make sure that the scarf stays attached to the jar. Leave the last jar without any wrapping. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information.
Your use of this information means that you agree to the Terms of Use. Learn how we develop our content. To learn more about Healthwise, visit Healthwise. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. Updated visitor guidelines. Top of the page. Topic Overview The body loses heat through: Evaporation of water from your skin if it is wet sweating.
Radiation similar to heat leaving a woodstove.
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