1. Keeping a house warm heat moves from regions of high temperature to
regions of lower temperature

2. the thermogram of a house shows where the heat is lost
and this costs and and

4. it is essential to reduce these losses because we can
save money
save energy resources
reduce pollution
reduce global warming
In a normal house reductions can be made if we make it more difficult for heat to move around …….
we can do this by …….

6. Hot objects always lose heat
heat transfer CANNOT be stopped
heat transfer can only be REDUCED by
loft insulation cavity wall insulation carpets
draught excluder double glazing
so what about radiators …………………???

7. a ‘radiator’ heats a space by convection
a lot of air moves about – gaining heat then losing heat then gaining heat again and so on
a ‘radiator’ heats a space by convection

8. the wall is an object so it will receive radiant heat as well
and by radiation as well

9. this INCREASES the radiant heat available in the room
putting shiny foil behind the radiator REFLECTS radiant heat back into in the room
this INCREASES the radiant heat available in the room

10. Hot objects always lose heat
to sum all this up
heat transfer CANNOT be stopped
heat transfer can only be REDUCED
there are 3 ways that heat is transferred
conduction
(solids only)
convection
(liquids and gases)
radiation
loft insulation cavity wall insulation carpets
draught excluder double glazing
REDUCE heat loss

11. just remember

12. So keep your house warm!! That’s all folks!
- 40°C outside
+ 2°C inside
not enough heat from the small lamp and the people to melt much ice and the floor is often covered in animal skins