Should I look at lumens or watts?

For LED selection, look at lumens — that measures light output. Watt is energy consumption and alone doesn't tell you how much light you get.

What's the difference between CRI 90 and CRI 80?

CRI 90 renders colours far more accurately. It's especially important in colour-sensitive applications like textiles, food and jewellery.

Which Kelvin is recommended for offices?

4000K neutral white is recommended for offices — it supports alertness and reduces eye fatigue. Meeting rooms can use 3000–4000K on a dimmable system.

EN 12464-1 requires UGR ≤ 19 for screen-based workspaces. Exceeding this causes glare discomfort and productivity loss.

What IP rating is needed for a garden?

IP65 for open outdoor and garden, IP67 for in-ground recessed fixtures, IP68 for in-pool applications.

LED Lighting Guide: How to Choose the Right Fixture

From lumens to CRI, colour temperature to IP rating — every technical term you need for lighting selection and space-by-space recommendations, all in one place.

1. What Is LED?

LED (Light Emitting Diode) is a semiconductor device that emits light when electric current passes through it. Compared to traditional incandescent and fluorescent lamps, LEDs are far more efficient, longer-lasting and environmentally friendly.

Energy Efficiency

Up to 80% less energy

Lifespan

50,000+ hours

Heat Output

Very low

2. Lumen vs Watt

Watt measures energy consumption — how much electricity is used. Lumen measures light output — how much light is produced. When choosing LEDs, lumen is the number that matters, not watts.

Application	Recommended Lumens	Typical LED Watt
Reading / Task	800–1,500 lm	7–14W
General Office	3,000–5,000 lm/m²	24–48W panel
Display / Accent	1,000–3,000 lm spot	10–25W spot
Street / Outdoor	5,000–20,000 lm	40–150W

3. CRI — Colour Rendering Index

CRI (Color Rendering Index) measures how accurately a light source renders colours compared to natural sunlight, on a scale of 0–100. A value of 100 represents perfect colour accuracy.

CRI < 80

Low

Warehouses, garages, industrial

CRI 80–90

Standard

Offices, corridors, general retail

CRI ≥ 90

High

Stores, fashion, cosmetics, hotels

4. Colour Temperature (Kelvin)

Kelvin (K) determines the tone of the light: low Kelvin gives a warm yellowish light, high Kelvin gives a cool bluish light.

Kelvin	Tone	Recommended Space
2700K	Warm White	Hotel rooms, bedrooms, restaurants, cafés
3000K	Warm Neutral	Showrooms, stores, residential living areas
4000K	Neutral White	Offices, meeting rooms, technical spaces
5000–6500K	Cool / Daylight	Warehouses, sports facilities, high-frequency workspaces

5. UGR — Unified Glare Rating

UGR (Unified Glare Rating) measures the discomfort glare produced by a luminaire. The lower the value, the higher the visual comfort. EN 12464-1 requires UGR ≤ 19 for screen-based workspaces.

UGR > 28

Unacceptable

Serious visual discomfort

UGR 19–28

Moderate

Short-duration tasks

UGR ≤ 19

Comfortable

Office, screen-based work

6. IP Rating — Dust and Water Protection

The IP (Ingress Protection) code shows how well a luminaire is protected against dust and water. It has two digits: the first for dust, the second for water.

IP	Protection	Typical Use
IP20	Partial dust	Dry indoors (living room, office)
IP44	Splash-proof	Bathroom, kitchen, sheltered outdoor
IP65	Jet-water resistant	Open outdoor, garden, façade
IP67	1 m submersion 30 min	In-ground, poolside
IP68	Continuous submersion	In-pool, underwater applications