energy transfer by heating

infrared radiation

heating and insulating buildings

specific heat capacity

transfer by conduction

best conductor is metal

best insulators

fibre glass

wool

higher thermal conductivity of material-high rate of energy transfer

thicker layer of insulator-lower rate of energy transfer

hotter the object-more infrared radiation being emitted

black body radiation

all objects emit and absorb infrared radiation

temp increase if object absorbs more radiation than emits

radiation emitted by a body

that absorbs all radiation incident on it

amount of energy need to change temperature of 1 kg of substance by 1 degree Celsius

energy transferred=mass x specific heat capacity x temperature change

greater mass of object, slower its temp increases

solar panels

how can rate of energy transfer from houses be reduced

cavity wall insulation

double-glazed window

loft insulation

aluminium foil behind radiators

absorb infrared radiation from sun

cheap way of heating home

fitted on roof usually facingsouth

generate electricity directly