KNOWLEDGE
Lighting infrastructure — what the specification process often overlooks.
Eight technical articles on what determines the service life, reliability, and value of a street luminaire over a luminaire's service life.
ARTICLES
Eight articles worth reading before you specify.
The questions most commonly left unanswered in a luminaire procurement.
MATERIALS & CORROSION · 01
Why luminaire housings corrode
Corrosion looks like a sudden failure in the field. It rarely is. This article explains the electrochemical process, the conditions that must be met simultaneously, and what material decisions interrupt that process.
SERVICE LIFE & RELIABILITY · 02
Why street luminaires fail
LED modules routinely reach 100,000 hours. The luminaire rarely does. A review of the mechanisms that actually limit street luminaire service life — and which are most common in practice.
SERVICE LIFE & RELIABILITY · 03
100,000 hours — what it actually means
The figure on every data sheet. What L70, L90, B10, and TM-21 actually measure — and what they don't. Understanding the difference between the LED module projection and whole-luminaire service life.
LIGHTING BASICS & PERCEPTION · 04
What is lumen?
Luminous flux output is the most cited figure in any specification. It is also one of the most misapplied. An explanation of what lumen measures, what it doesn't, and why illuminance on the road surface is a more useful criterion.
SERVICE LIFE & RELIABILITY · 05
What do L70 and L90 mean?
Two numbers that appear on every LED data sheet. A clear explanation of lumen maintenance curves, B-values, and how to use them — and misuse them — in procurement specifications.
SERVICE LIFE & RELIABILITY · 06
Moisture, condensation and failure modes
IP66 is measured on a new luminaire in a test chamber. This article explains what happens to luminaire sealing over time — and the distinction between a corrosion-resistant housing and a genuinely sealed one.
PROCUREMENT & STANDARDS · 07
Purchase price vs lifecycle cost
A procurement that compares only purchase price consistently misses the costs that matter most over a 20-year service period. A framework for lifecycle cost analysis in public lighting procurement.
SERVICE LIFE & RELIABILITY · 08
Why the driver's capacitors determine service life
Electrolytic capacitors are the most temperature-sensitive component in a luminaire driver. Understanding how ambient temperature, driver loading, and thermal design affect capacitor lifespan.
WHY THIS SECTION EXISTS
Not a product brochure.
This knowledge centre is built on the same technical foundation that underpins our product documentation — from fundamental concepts such as lux and luminance to open questions the industry has not yet resolved.
The content is written to explain lighting, materials, and service life in real-world operation. Where relevant, VALDUR is mentioned as an example — but the articles are written to be useful regardless of which luminaire you currently specify.
HOW THE ARTICLES CONNECT
From one question to a cost — in four steps.
The series on why street luminaires fail is a concrete example of how the articles build on one another: an entry article, three root causes, an economic consequence — with further depth articles to follow in 2026.
Root causes
Why luminaire housings corrode
Galvanic corrosion, salt spray, and moisture attack different materials at different rates.
Moisture, condensation and failure modes
Most field failures begin with moisture ingress — long before a visible fault appears.
Why the driver's capacitors determine service life
Thermal ageing of electrolytic capacitors is one of the mechanisms behind premature failure.
In depth · forthcoming
Thermal cycling and solder joint fatigue
How diurnal and seasonal temperature swings mechanically fatigue solder joints over time.
MTBF vs actual service life
Why a high MTBF figure is not the same as a service life guarantee.
What fails first in an LED luminaire?
Capacitors, solder joints, seals, and connectors age at different rates.
Warranty vs expected service life
Two distinct commitments that are easily conflated — but mean very different things.
ARTICLE INDEX
What is in progress.
Articles are published on a rolling basis throughout 2026, section by section. The list below shows how they are organised.
Lighting Basics
- What is lumen?
- What is lux?
- What is candela?
- What is luminance?
- What is colour temperature?
Light Quality & Perception
- What is mesopic vision?
- What is the Purkinje shift?
- Why the same lux level is not always perceived equally
- Glare and road safety
- Is 3000 K or 4000 K better?
Optics & Lighting Calculation
- Why the same lumen output doesn't give the same road result
- DIALux and Relux vs reality
- What happens to light on wet asphalt?
- What does uniformity mean in road lighting?
- Lux vs luminance
Service Life & Reliability
- Why street luminaires fail
- What fails first in an LED luminaire?
- Purchase price vs lifecycle cost
- What do L70 and L90 mean?
- MTBF vs actual service life
- Why IP rating degrades over time
- Moisture, condensation and failure modes
- Why the driver's capacitors determine service life
- Warranty vs expected service life
- Thermal cycling and solder joint fatigue
- What do long-term studies say about real-world performance?
Materials & Corrosion
- SMC vs aluminium
- What is galvanic corrosion?
- Why luminaire housings corrode
- Corrosion in coastal environments
- Material selection and service life
- Class II electrical safety and insulated enclosures
- Why radio transparency matters for wireless controls
Controls & Smart Infrastructure
- What is DALI?
- What is Zhaga?
- What is adaptive dimming?
- When are sensors needed in road lighting?
- Are we dimming too much at night?
Procurement & Standards
- What does IP66 mean?
- What does IK10 mean?
- What is C5-M?
- What is EN 13201?
- 100,000 hours — what it actually means
Open Questions
- Are today's corrosion tests realistic?
- Is there a perfect colour temperature?
- Are high masts the future?
- How much is gained from mesopic modelling?
- What is the net effect of snow on safety?
SPECIFICATION
Specify for the full service life.
Have a technical question about lighting, materials, or service life that isn't covered here? Get in touch — we are happy to let real questions guide our choice of future articles.