L4 Heat & Air - Thermal performance of buildings

Question 1

Describle Conduction

Answer 1

Conduction is the direct transfer of heat through material - Conductance is the amount of heat that passes through 1sqm of material 1m thick for 1k temperature difference between inside and outside.

Question 2

Describe Radiation

Answer 2

Radiation is the transfer of heat from one surface across a space - The rate of transfer depends on the nature of surfaces eg. absorption and reflectance.

Question 3

Describe Convection

Answer 3

Convection is the transfer of heat through air movement - The change of density causes convection currents which can transfer heat to or from surfaces