Guiding light | Archive Titles | Building

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Table 1: Luminaire control factors
Control function	C_L
a) The luminaire is in daylit space (see paragraph 1.45), and its light output is controlled by A photoelectric switching or dimming control, with or without manual override, or Local manual switching (see paragraph 1.57a)	0·80
b) The luminaire is in a space that is likely to be unoccupied for a significant proportion ofworking hours and where a sensor switches off the luminaire in the absence of occupants but switching on is done manually	0·80
c) Circumstances a) and b) above combined	0·75
d) None of the above	1·00

Table 2: Maximum area of openings unless compensating measures are taken
Building type	Windows and doors as % of the area of exposed wall	Rooflights as % of area of roof
Residential buildings (where people temporarily or permanently reside)	30	20
Places of assembly, offices and shops	40	20
Industrial and storage buildings	15	20
Vehicle access doors and display windows and similar glazing	As required

Table 3: Light sources meeting the criteria for general lighting
Light source	Types and ratings
High pressure sodium	All types and ratings
Metal halide	All types and ratings
Induction lighting	All types and ratings
Tubular fluorescent	26 mm diameter (T8) lamps, and 16 mm diameter (T5) lamps rated above 11 W, provided with high efficiency control gear. 38 mm diameter (T12) linear fluorescent lamps 2400 mm in length.
Compact fluorescent	All ratings above 11 W
Other	Any type and rating with an efficacy greater than 50 lumens per circuit Watt.

Table 4: Maximum power consumption of high efficiency control gear
Nominal lamp rating (W)	Control gear power consumption (W)
Less than or equal to 15	6
Greater than 15, not more than 50	8
Greater than 50, not more than 70	9
Greater than 70, not more than 100	12
Greater than 100	15

Table 5: Light sources meeting the criteria for display lighting
Light source	Types and rating
High pressure sodium	All types and ratings
Metal halide	All types and ratings
Tungsten halogen	All types and ratings
Compact and tubular fluorescent	All types and ratings
Other	All types and rating with an efficacy greater than 15 lumens per circuit watt.