Light Transmittance - Lt
The light transmittance coefficient, is a parameter, which describes the percentage of light (falling on angle close to 90%), which passes the glass. The lower is the ‘Lt’ coefficient, the more light passes through the windows and lights up the room inside.
Windows with high Lt coefficient of the glass allow more light inside the building. This saves the electricity used for lighting.
Retained light 30%
Passed light 70%