Luminous flux
According to BRE’s The essential guide to retail lighting: The term 'luminous flux' describes the ‘amount of light produced by a lamp; usually measured in lumens’. Lumen are related to lux (lx), the SI unit of illuminance, or amount of light on a surface, in that one lux is equal to one lumen per square metre (lm/sq. m)
The Illustrated Guide to Electrical Building Services, Third Edition (BG 31/2017), by David Bleicher & Peter Tse, published by BSRIA in 2014, states: ‘Luminous flux is the quantity of light emitted by a lamp and is measured in lumens (lm). A 60 W incandescent lamp (formerly commonplace but now obsolete) emits about 700 lm, and a 28 W T5 fluorescent lamp emits about 2600 lm. It can be seen from this comparison that incandescent lamps are less energy efficient than discharge lamps.’
[edit] Related articles on Designing Buildings Wiki
- Ballast or control gear.
- 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.
- Illuminance.
- Lamp.
- Lamp efficacy.
- Light pollution.
- Lighting.
- Lighting energy numeric indicator LENI.
- Lighting of construction sites.
- Luminaire efficacy.
- Lux.
- Rights to light.
- Voltage.
Featured articles and news
Conservation in the age of the fourth (digital) industrial revolution.
Shaping the future of heritage
Embracing the evolution of economic thinking.
Ministers to unleash biggest building boom in half a century
50 major infrastructure projects, 5 billion for housing and 1.5 million homes.
RIBA Principal Designer Practice Note published
With key descriptions, best practice examples and FAQs, with supporting template resources.
Electrical businesses brace for project delays in 2025
BEB survey reveals over half worried about impact of delays.
Accelerating the remediation of buildings with unsafe cladding in England
The government publishes its Remediation Acceleration Plan.
Airtightness in raised access plenum floors
New testing guidance from BSRIA out now.
Picking up the hard hat on site or not
Common factors preventing workers using head protection and how to solve them.
Building trust with customers through endorsed trades
Commitment to quality demonstrated through government endorsed scheme.
New guidance for preparing structural submissions for Gateways 2 and 3
Published by the The Institution of Structural Engineers.
CIOB launches global mental health survey
To address the silent mental health crisis in construction.
New categories in sustainability, health and safety, and emerging talent.
Key takeaways from the BSRIA Briefing 2024
Not just waiting for Net Zero, but driving it.
The ISO answer to what is a digital twin
Talking about digital twins in a more consistent manner.
Top tips and risks to look out for.
New Code of Practice for fire and escape door hardware
Published by GAI and DHF.