Air-Flow

Air Flow Coefficient
The relative efficiency with which air can flow through an aperture, vent or duct.
Air Infiltration
The rate that outside air leaks uncontrolled into a building or through a component.
Air Porosity
A measure of how well air can enter the volume of a material.

Light

Colour
Information on how we perceive the colour of materials and objects.
Light Absorptance
Light absorptance is the ratio of absorbed to incident light on a material.
Light Behaviour
The behaviour of light can sometimes be quite complex in its simplicity.
Light Reflectance
Reflectance measures the ratio of reflected light to total incident light.
Light Refraction
Refraction is the bending of light when it moves between materials.
Light Transmittance
Light transmittance is the ratio of transmitted to incident light through a material.
Reflectivity and Reflectance
Reflectance and reflectivity values are often the same, but the concepts certainly aren't.
Refractive Index
The ratio of the speed of light in a vacuum to the apparent speed of light in a material.
Specularity
Specularity is a surface property affecting the angular distribution of reflected light.