Lighting in Design Q2 2024

electrodes and a gas in-between the electrodes (in this case, metal halide),” explains Horlacher. “Typically, metal halide lamps produce 70-100 lumens per watt of electricity consumed. So, for a 150W metal halide at 85 lumens per watt, that would be 12 750 lumens. The part of the metal halide lamp that produces the light can be either ceramic or quartz, typically 20mm x14 mm, with a total light-producing area of 2 653 mm 2 – 12 750 lumens divide by 2 653 mm 2 = 4.8 lumens per

mm 2 .” “Lastly, we look at LEDs. A 5050 chip operating at 6V and 700mA = 4.2VA or watts. This chip measures 5mm x 5mm = 25mm 2 . The efficacy of a 5050 LED chip is in the region of 160 lumens per watt, so 4.2 x 160 = 672 lumens, which in turn means 672 lumens divided by 25mm 2 to equal 26.8 lumens per mm 2 ,” explains Horlacher. “This makes LEDs a very bright light source to have in direct line of sight.” Enquiries: www.giantlight.co.za

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LiD Q2 - 2024