Energy lesson 7

REDUCING HEAT LOSSES

TargetTo know the main ways in which heat is lost

from the home

Monday, May 1, 2023

Heat loss from homes Look at the diagram

and complete the table

Part of house Heat lost per secceilingwindowsfloordraughtswall

2000 Joules1500 Joules1000 Joules

1500 Joules

4000 Joules

Heat loss from homes Look at the diagram

and complete the table

Part of house How heat is lostceilingwindowsfloordraughtswall

Conduction

Conduction

Conduction

Convection

Conduction

Heat loss saving in homes Draughts Use draught excluders

– cuts down half heat loss

Heat loss saving in homes Double glazing Air trapped stops half

heat loss

Heat loss saving in homes Loft insulation Air trapped in glass

fibre cuts down half heat loss through the ceiling

Heat loss saving in homes Cavity wall insulation Air trapped in fibre

cuts down heat loss through the wall

Pay back time Cavity walls Costs £450 Saves £ 75 per year Payback time = 450 / 75 = 6 years

Pay back time Draught excluders Costs £25 Saves £ 50 per year Payback time = 25/ 50 = 0.5 years = 6 months

Pay back time Double glazing Costs £2400 Saves £ 60 per year Payback time = 2500 / 60 = 40 years

Pay back time Loft insulation Costs £300 Saves £ 150 per year Payback time = 300 / 150 = 2 years

QUESTIONS

Foundation Science 1 - Pages 174 and 175Draw the diagram.

Copy and complete the summary box

The vacuum flask

Vacuum prevent conduction and convection

Silvered surfaces inside prevent radiation

Top prevents convection