- 3.1 Introduction
- 3.2 Heat transfer introduction
- 3.3 Power conversion
- 3.4 LED performance
- 3.5 Thermal design of LED-based luminaire
- 3.6 Cooling system
- 3.7 Thermal design of passive cooling
- 4.1 Cold lumens versus hot lumens
- 4.2 Driving LEDs
- 4.3 LED connection
- 4.4 LED driver
- 4.5 LED driver additional features
- 5.1 High Efficacy
- 5.2 Controllability
- 5.3 Size
- 5.4 Directionality
- 5.5 Durability
- 5.6 Low-temperature operation
- 5.7 Instant on, frequent switching
- 5.8 No UV emissions
- 5.9 Environmental impact
- 5.10 Reliability and lifetime
- 6.1 The Right Light Application
- 6.2 Presentation and retail shop, shopping mall
- 6.3 Industry and engineering, outdoor workplaces
- 6.4 Office and communication
- 6.5 Hotel and gastro
- 6.6 Architecture, facade, city marketing and visual presentation
- 6.7 Road path and square
- 6.8 House, flat and living area
- 6.9 Emergency lighting
- 7.1 High brightness LED market
- 7.2 Lighting Efficiency Comparison
- 7.3 HB LED
- 7.4 LED luminaire cost track
- 7.5 LED retrofits versus LED luminaires
3.4 Cooling System
Excess heat affects directly short-term and long-term LED performance.
- Short-term: color shift and light output reduction.
- Long-term: accelerates lumen depreciation and shortens lifetime.
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| LEDs on heat sinks |
LED luminaries with fan 1 & 2: Fan, 3: LED, 4: Light reflector |
Natural and forced cooling systems are commonly used for heat dissipation.
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Natural cooling system, such as heat sink, refers to technologies or design features used to cool-down the light source without power consumption.
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Forced cooling system, such as fan or synthetic jet, consumes extra power in order to drive heat away thus cool-down light source.
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With the same LED module, two different cooling systems are applied due to different working environments.
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LED luminaire with forced cooling - synthetic jet |
LED luminaire with natural cooling - heat sink |
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Left picture shows forced cooling system on the LED module which is called synthetic jet. It is a type of the jet flow which is synthesized from the ambient air. |
In the left picture, there is natural cooling system on module commonly called heat sink. It is a component or assembly that transfers heat generated within LED module into the air. |
| 3.5 Extraction of a Heat from LED | ||
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