Lighting Formula:
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The Lighting Watts Calculation determines the total wattage needed to achieve a desired level of brightness (in lumens) based on the efficiency of the light source (lumens per watt). This helps in selecting appropriate lighting fixtures and planning energy requirements.
The calculator uses the lighting formula:
Where:
Explanation: The equation calculates the total wattage required by dividing the desired brightness by the efficiency of the light source.
Details: Proper lighting calculations ensure adequate illumination for spaces while optimizing energy efficiency. It helps in selecting the right fixtures and determining electrical load requirements.
Tips: Enter the desired lumens (brightness) and the lumens per watt (efficiency) of your light source. Both values must be positive numbers.
Q1: What are typical lumens per watt values?
A: Incandescent: 10-17 lm/W, Halogen: 16-24 lm/W, CFL: 40-70 lm/W, LED: 80-120+ lm/W.
Q2: How many lumens do I need for a room?
A: Living rooms need 10-20 lumens/sq.ft, kitchens 30-40, offices 50-75. Multiply by room area for total lumens.
Q3: Why calculate watts instead of just using lumens?
A: Watts determine energy consumption and electrical load, important for energy efficiency and circuit planning.
Q4: Does this account for light loss factors?
A: No, for precise calculations you may need to account for fixture efficiency, room reflectance, and maintenance factors.
Q5: Can I use this for outdoor lighting?
A: Yes, but outdoor lighting often requires higher lumens due to lack of reflective surfaces.