Thermal indices for the built environment
g-value (sometimes referred to as window solar factor, solar factor or total energy transmittance (TET)). The fraction of incident solar radiation transmitted by a window, expressed as a number between 1 and 0, where 1 indicates the maximum possible solar heat gain, and zero, no solar heat gain. NB The difference between g-values and solar heat gain coefficients is that they use a different value for air mass.
Psychometric charts. Graphs that can be used to assess the physical and thermodynamic properties of gas-vapour mixtures at a constant pressure.
R-value. A measure of the thermal resistance of a material of a specific thickness.
Shading coefficient. The amount of solar heat that passes through a transparent or translucent material compared to the amount of solar heat that passes through a sheet of clear float glass with a total solar heat gain coefficient of 0.87 (ie a sheet of clear float glass 3mm thick which has a shading coefficient of 1).
Solar heat gain coefficient. The fraction of incident solar radiation transmitted by a window, expressed as a number between 1 and 0, where 1 indicates the maximum possible solar heat gain, and zero, no solar heat gain. NB The difference between g-values and solar heat gain coefficients is that they use a different value for air mass.
Thermal comfort. ‘…that condition of mind which expresses satisfaction with the thermal environment’.
Thermal optical properties. Characteristic radiant behaviour within the thermal spectrum.
 Related articles on Designing Buildings Wiki
Featured articles and news
Why buildings crack, how cracks are categorised and what can be done.
Inaugurated last week, the new Elbphilharmonie concert venue; a soaring new addition to Hamburg's skyline.
Summary of a new ICE Transport journal which says improving transport infrastructure is essential to eradicating global poverty.
BRE look at a new government report into the accuracy of heat meters.
Herzog & de Meuron get planning permission for revamp of Chelsea FC football stadium.
UK-GBC green paper proposes more powers for cities on new-build housing.
The Pompidou Centre – not a monument but an event.
The Chartered Institute of Building restructures and launches 29 new local hubs.
Designing Buildings Wiki talks to the founder of the world's first indoor biophilic gym, now open in London.
£1.3bn Swansea Bay project to be backed as a 'pathfinder' for other tidal lagoon projects.
Designs released for a proposed Las Vegas stadium to entice the Oakland Raiders.
Have a look at these award-winning concept designs for a thermal bath in Latvia.