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Conserving energy in a house
There are several aspects to teaching about conserving energy in a house. Students should know about different ways to insulate a house and that some types of insulation are more effective than others. Students should also be aware of the cost of wasting energy, and how energy use is linked to global warming. The main objectives are outlined below:
1. All students should know that there are different ways to insulate a house.
2. All students should know that some types of insulation are more effective than others.
3. All students should know that wasting energy costs money.
4. Most students should be aware that wasting energy is a factor in global warming.
5. Most students should be able to tell which are the most effective types of insulation in houses.
6. Some students should be able to explain why some types of insulation are better.
The Energy house simulation
The Energy house was created as a qualitative model of how insulating a house affects heating bills. The figures involved are not exact, but act as a rough comparison of the effectiveness of different types of insulation. Higher-level students should be thinking about the transfer of energy, and how each type of insulation stops that transfer.
As well as the knowledge objectives outlined above, there are several ways you can use this program for processing skills. Overall, it is a versatile piece of software that students like using. Because there are so many options, it is wise to keep the students as directed as possible. This program is ideal for open-ended tasks for higher-level students. You could ask questions such as:
'What is the best way to insulate a house if you have a budget of ?25,000?'
'Which is more important: wall insulation or double glazing? Why?'
Students could then explore the simulation to find out the answers.
It is equally good for basic-level students if you set them tasks to complete, such as:
'Which is the best type of wall insulation?'
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Suggestions for tasks
Here are some suggestions for tasks you could set, matched to the objective they address and the approximate level of difficulty. Not all of them are as simple as you might think. The answer to 3H, for example, is 'double glazing'. Why? Ask students to look at the total cost after 20 years. These are just suggestions and are by no means a comprehensive list. The versatility of the Energy house means you can set a whole variety of tasks.
1 H Which part of the house would you insulate first of all? Why?
I What is the cheapest type of insulation?
B How many types of insulation are there?
2 H Which type of insulation reduces energy loss most?
Which would you rather do, double glaze your windows or insulate I your loft?
B What type of insulation would you put in your loft?
Which costs less, putting in double glazing or fitting a carpet with 3 H underlay?
How much money does it cost per year to turn up the heating by I 1?C?
How much energy do draught excluders save? How much money B can they save you?
4 H/I Where does the energy go when it has left the house?
H/I Write a list of the most effective types of insulation.
H How would you insulate a house if you had a budget of ?27,000?
Which type of energy transfer does CFG stop? How do you think it 6 H works?
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How to use the Energy house program
Section 1: The Costs sheet
This is where you should start. There is only one option you can change here and that is the currency. The currency you choose also determines the ambient (outside) temperature for the whole program, and uses the average temperature for the capital city of that currency's country. e.g. if you choose US dollars as your currency, then your house will be in Washington DC. The Costs sheet is also where you see the bill for your house. This is derived from the amount of energy lost through the house. It is meant as a qualitative tool and not as a predictor of how much your heating bill will be. The bill is worked out for the whole year when it is displayed on the costs page.
Section 2: The Options sheet
Here is where you make all the changes to the house. There is a drop-down menu for each area of the house that you can insulate.
Each area has two or three options to choose from. There is also a 'thermostat' to set the temperature inside the house.
Most options are self-explanatory. However the type of brick and roof tile used makes little difference to the effectiveness of the insulation.
Peterborough bricks are usually regarded as the most attractive and sought-after building material, and London bricks the least. Manchester bricks are a compromise between the two. Peterborough bricks are slightly darker than Manchester bricks, which are slightly darker than London bricks.
For loft and wall insulation, Cavity Fibre Glass (CFG) is a material with a great many small pockets of air, and lagging is simply thick cloth.
The thermostat works on a sliding scale between 20?C and 35?C. The same temperature is applied to the house throughout the whole year.
Section 3: The Energy house sheet
This picture gives a clear indication of where the energy goes when you heat a house. There are no variables to change on this sheet.