Heating and insulating buidligns, specific heat capacity

Question 1

Equation for payback time?

Answer 1

Payback time = inital cost / annual saving

Question 2

Ways you can insulate home? Explain them?

Answer 2

• Loft insulation

A thick layer of fibreglass wool laid out acrooss the whole loft flood reduces conduction and radiation into the roof space from the ceiling

• Hot water tank jacket

Lagging sich a fibreg;ass wool reduces conduction and radiation

• Double glazing
• Draught proofing

Strips of foam and plastic around doors and windows stop draughts of cold air blowing in - reducing heat loss due to convection

• Cavity wall insulation

Foam squirted into the gap between the bricks stops convection currents being set up in the gap and radiation across the gap. The insualting foam and the air pockets trapped in it also helps reduce heat loss by conduction

• Thick curtains

Reduce heat loss by conduction and radiation

Question 3

What are the most effective methods of insulation?

Answer 3

The ones that give you the biggest annual saving

Question 4

What is payback time?

Answer 4

The time taken for the money youve saved on heating bills equals the initial cost of putting in the insulation

Question 5

What are the most cost-effective ways on insulating? Why?

Answer 5

The ones which are the cheapest

→They have a short payback time

Question 6

What do U-Values show?

Answer 6

How fast heat can transfer though a material

Question 7

How does an objects U-Value tell you how fast it transfers heat?

Answer 7

Heat transfers faster through materials with higher U-Values than ones with low U-Values

Question 8

U-Value; the better the insulator..

Answer 8

The lower the U-Value