Lesson 2.3 - Keeping Heat In

Houses are insulated in various ways.  The most common insulation for walls in a house is fibreglass.  An improvement can be made for fibreglass insulation.  You may have seen insulation that has one side with a shiny surface.  What is the purpose of this shiny surface? 

Read Other Ways to Keep Heat in Your House and the Find Out Activity on page 114 in your textbook.

You are now going to perform this Activity.  Instead of beakers, you will use ordinary drinking glasses.  You can use an ordinary outdoor thermometer to measure the temperature of the water.  Perform the activity using hot tap water and complete the following table.

Answer questions 1 and 3 of What Did You Find Out? on page 114 in your textbook. 

Answer question 4 of Conclude and Apply on page 114 in your textbook. 

 

Check your answers with those that follow.

 

 

 

 

 

 

 

 

 

 

 

Answers to What Did You Find Out? questions:

Question 1. The glass that did not have the aluminum foil lost the most heat. 

Question 3. The foil reduces heat transfer by radiation. 

 

Answer to Conclude and Apply question:

Question 4.
a) The R-value for 25 mm of air space in a wall cavity is 2.04 
b) The R-value for 25 mm of air space with a reflective surface in a wall cavity is 5.54.
c) Foil reduces heat transfer.  
d) Yes, the results of this activity should agree with the information in the table.  

 


Go to the next page to continue Lesson 2.