Unit 1 - Insulation Flashcards
What does the U-value of a material tell you?
How good an insulator is it. The lower the value the better insulator it is. A perfect insulator will have a zero U value.
How do solar panels containing water work?
They absorb the radiation from the sun, heating the water which can be used to heat buildings or provide hot water for washing.
What is specific heat capacity?
The amount of energy needed to raise the temperature of 1kg of a material by 1 degree centigrade. If something has a high specific heat capacity, a lot of energy is needed to do this!
Give the unit for specific heat capacity.
J/Kg0C
Why is double glazing a better insulator than single glazing?
The double glazing traps air between the layers of glass. Air is. A bad conductor. Trapped air reduces heat transfer by convection.
How does loft insulation or cavity wall insulation reduce heat transfer?
The air is trapped between the fibres of the insulation. Air is a bad conductor. Trapped air can not circulate so this reduces the heat transfer by convection.
