#Daylight + lighting
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
02. daylight + <strong>lighting</strong><br />
10(23)<br />
Daylight: (factor)<br />
(For determining use in buildings), is<br />
considered to have 3 components:<br />
Sky Component (SC): The ratio of that part<br />
of the daylight illuminance at a point on<br />
a given plane which is received directly<br />
from the sky.<br />
Externally Reflected Component (ERC):<br />
The ratio of that part of the daylight<br />
illuminance at a point on a given plane<br />
which is received directly from external<br />
reflecting surfaces, illuminated directly<br />
or indirectly by the sky.<br />
Internally Reflected Component (IRC):<br />
The ratio of that part of the daylight<br />
illuminance at a point on a given plane<br />
which is received from internal<br />
reflecting surfaces.<br />
The daylight factor is the sum of the 3 components.<br />
DF = SC + ERC + IRC<br />
The daylight factor can be expressed in two different ways.<br />
Service Daylight Factor (SDF): The value of the daylight factor under<br />
service (normal) conditions. ie, unclean windows, dust on reflective<br />
louvres etc.<br />
Design Daylight Factor (DDF): The value of the daylight factor under<br />
optimal (perfect) conditions.
Change language