Downlights
We use the standard lumen method from lighting design:
lumens needed = target lux × room area (m²) ÷ utilization factor
Target lux follows residential guidelines: living 200 lx, dining 250 lx, kitchen 400 lx, bedroom 150 lx, bathroom 250 lx, study 500 lx, hallway 100 lx. We assume a utilization factor of 0.6 for typical Malaysian ceilings (2.7–3.0 m, light walls). A common 9W LED downlight produces about 900 lumens, so:
fixture count = ceil(lumens needed ÷ 900)
Spacing is the square root of (room area ÷ fixture count), which gives a balanced grid layout. For high ceilings (>3 m) or dark walls, round up by one extra fixture.
Ceiling fan blade span
Blade span is matched to room area so airflow covers the whole space:
- Under 8 m² — 36"
- 8–14 m² — 42"
- 14–21 m² — 48" to 52"
- 21–28 m² — 56"
- 28–37 m² — 60"
- Over 37 m² — 72" or two fans
Downrod length aims for blades sitting about 2.3 m off the floor (ideal airflow, safe clearance). So:
downrod ≈ ceiling height − 2.3 m − 0.3 m motor
Below ~2.6 m ceilings, we recommend a hugger / low-profile fan instead of a downrod.
LED watt equivalent
Rough divisors based on real-world lumen output:
- Incandescent ÷ 7 = LED watts
- Halogen ÷ 5 = LED watts
- CFL ÷ 3 = LED watts
Estimated lumens use a typical efficacy of 100 lm/W for modern LEDs. Premium LEDs reach 120 lm/W; budget ones sit closer to 80 lm/W.
These are guidelines, not a substitute for a lighting plan. For renovations, layered lighting (downlights + accent + task) usually beats a single calculation. Bring your floor plan to the Sri Damansara showroom and we'll work it through with you.