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P1 – AQA 2011 P1.1. The Transfer of Energy Mr. J. McHugh J.McHugh.

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Presentation on theme: "P1 – AQA 2011 P1.1. The Transfer of Energy Mr. J. McHugh J.McHugh."— Presentation transcript:

1 P1 – AQA 2011 P1.1. The Transfer of Energy Mr. J. McHugh J.McHugh

2 Learning Objectives  To state what U-values are  Evaluate the effectiveness of different types of material used for insulation, including U-values and economic factors including payback time J.McHugh

3 What IS a U-value?  Used in Europe to help architects choose building materials  Tells us how well heat passes through a material  The lower the U-value, the less heat passes through J.McHugh

4 What does it mean?  The energy that passes through is measured in WATTS ( 1W = 1J/s )  A U-value tells us how much energy passes through 1m 2 of a material with a particular thickness  The standard U-value looks at the energy transferred (W) where there is a 1°C temperature difference between the two sides of material  Thus, the unit for a U-value is W/m 2 /°C J.McHugh

5 Using U-values  Different materials have different U-values  Energy lost can be calculated as E = U-value x area x temperature difference ( W/m 2 /°C ) (m 2 )(°C) J.McHugh

6 Old Single Glazing  Old single glazed windows with a metal frame  Typical U-value = 5.6  Area = 1m 2  Inside Temp. = 20°C  Outside Temp. = 10°C Calculate energy lost J.McHugh

7 Class Task  Longman Worksheet P1a.2f – Calculating Energy Losses [H] J.McHugh

8 Homework 1. Complete Keeping Warm worksheet 2. Finish Calculating Energy Losses worksheet DUE: Wednesday December 8 th J.McHugh


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