E14 LED home light bulb 4.0W Main advantage of filament, 1w = 100Lm Fiber design lamp for built-in ceiling, crystal chandeliers. With gentle electrolux. Filament type with clear glass. The energy efficiency of light bulbs is expressed in lm / W. There are currently a number of different bulbs with different efficiencies. Energy-efficient LED bulbs are on average 5 to 10 times more efficient than a filament lamp. Consequently, LED bulbs reduce energy consumption and costs by 50-90% compared to a standard lighting solution.