LED Downlight Technical FAQ
What is an LED downlight?
An LED downlight is a recessed lighting fixture designed to provide focused and uniform illumination. It is commonly used in residential, commercial, and architectural lighting applications.
What is the difference between slim (wafer) and traditional recessed downlights?
Slim (wafer) downlights:
Ultra-thin design
No housing required
Remote driver (junction box included)
Ideal for retrofit and tight ceiling spaces
Traditional recessed downlights:
Require housing (can)
Deeper installation
Used in new construction
Slim downlights are widely preferred for modern installations.
What is a retrofit downlight?
Retrofit downlights are designed to replace existing recessed fixtures without major modifications.
They typically:
Fit into existing housings
Use E26 connectors or direct wiring
Provide quick upgrades to LED
What is 5CCT or selectable color temperature?
5CCT downlights allow switching between multiple color temperatures:
2700K
3000K
3500K
4000K
5000K
Selection is typically done via a switch on the fixture or driver.
What is lumen output and how should it be selected?
Lumen output determines brightness.
Typical guideline:
600–800 lumens → residential
800–1200 lumens → general commercial
1200+ lumens → high output applications
Spacing and ceiling height must also be considered.
What is beam angle and why is it important?
Beam angle determines light distribution.
Narrow beam → focused lighting
Wide beam → general illumination
Downlights typically range from 60° to 120°.
What is CRI in downlighting?
CRI (Color Rendering Index) measures color accuracy.
CRI 80+ → standard
CRI 90+ → high-quality lighting
Recommended for:
Retail
Hospitality
Residential
Are LED downlights dimmable?
Yes. Most downlights support:
TRIAC (phase-cut dimming)
Compatibility with dimmers must be verified to avoid flickering.
What is IC rating in downlights?
IC-rated downlights are safe for direct contact with insulation.
Non-IC rated fixtures require clearance from insulation.
IC rating is important for building code compliance.
What is air-tight (AT) rating?
Air-tight downlights prevent airflow between conditioned and unconditioned spaces.
Benefits:
Improved energy efficiency
Reduced air leakage
Required in many residential codes.
What voltage do LED downlights operate on?
Most downlights operate on:
120V AC (North America)
Some systems use low voltage with external drivers.
What certifications are required for downlights?
Common certifications:
UL / ETL
Energy Star (in some cases)
FCC
Certification ensures compliance with electrical and safety standards.
Can LED downlights be used in wet or damp locations?
Yes, if rated appropriately:
Damp rated → bathrooms, kitchens
Wet rated → showers, outdoor soffits
Always verify rating.
What sizes are available for LED downlights?
Common sizes:
3 inch
4 inch
6 inch
Size selection depends on ceiling cutout and lighting design.
How should downlights be spaced?
General spacing guideline:
4 to 6 feet apart
Depends on:
Ceiling height
Lumen output
Application
What is the lifespan of LED downlights?
Typical lifespan:
30,000 – 50,000 hours
Proper installation and heat management extend lifespan.
What are common installation mistakes?
Incorrect cutout size
Improper wiring
Using incompatible dimmers
Ignoring IC rating
Over-spacing fixtures
Do LED downlights require maintenance?
LED downlights require minimal maintenance compared to traditional lighting.