- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 09 Feb 2017
According to BRE’s The essential guide to retail lighting:
Luminaire efficacy is the ‘Light output of an entire luminaire divided by the total power consumed by the lamps and ballasts. Equal to the lamp efficacy multiplied by the light output ratio of the luminaire.’
Ballast or control gear, is ‘Part of the control equipment of fluorescent or discharge lamps, used to stabilise the current. The older, traditional main-frequency ballast can consume up to 20-25% of the total lamp current. A modern electronic ballast working at high frequency consumes about 30% less current, and can be used to regulate or dim the lamp output.’
 Find out more
 Related articles on Designing Buildings Wiki
- Ballast or control gear.
- BRE articles.
- Colour appearance.
- Daylight benefits in healthcare buildings.
- Daylight factor.
- Daylight lighting systems.
- Dichroic reflector.
- Discharge lamp.
- Extra-low voltage lamps.
- General lighting v task lighting.
- Lamp efficacy.
- Light pollution.
- Lighting energy numeric indicator LENI.
- Lighting of construction sites.
- Rights to light.
Featured articles and news
Rich opportunities lie in the jigsaw of the Highlands and Islands.
Five hugely demanding projects.
Conversion of Blairtum House, Lanarkshire
Why civil engineering is the 'best' career.
Green rating systems
Information is the lifeblood of quality management.
How PowerLottery helps industry colleagues.
Eliminating waste through blockchain.
Emerging cost contracts.
Connecting infrastructure with housing.
All about E-procurement.