Energy efficiency Flashcards
What are 5 types of insulation that can be used in the home to save money and energy?
Hot water tank jacket Double glazing Draft proofing Cavity wall insulation Lost insulation
What are the most effective methods of insulation?
What is the equation for payback time?
The ones that give you the largest annual saving
Payback time= initial cost / annual saving
The most cost effective methods tend to be the ….
as they have a short …… time
cheapest
pay back
What is draught-proofing?
What energy transfer does it prevent?
Strips of foam and plastic around doors and windows to stop draughts of cold air blowing in
Reduces heat lost to convection
What is loft insulation?
What energy transfer does it prevent? (2)
A thick layer of fiberglass wool laid out across the whole loft floor
Radiation and conduction from the ceiling into the roof space
What is cavity wall insulation?
What energy transfer does it prevent?
Foam squirted into the gap between the bricks
Reduces convection, conduction and radiation across the gap
What are thick curtains used for?
What energy transfer does it prevent?
As big bits of cloth over the window
Reduce heat loss by conduction and radiation
What is hot water tank jacket?
What energy transfer does it prevent?
Padding such as fiberglass wool
Reduces conduction and radiation
What do U-values show?
How fast heat can transfer through a material
The better the insulator the …… the U-value
lower
Heat transfers through materials with high U-values …… than materials with low U-Values
fatser
What is specific heat capacity?
The amount of energy needed to raise the temperature of 1kg of a substance by 1 degree centigrade
Materials that need a lot of energy to warm up do what when they cool down?
Release a lot of energy because they store a lot of energy
What is water’s specific heat capacity?
4200 J/kg°C
What is the formula for specific heat capacity?
E= m x c x Ø Energy transferred (J) = mass (kg) x spec heat c x 0 (temp change)
