simply providing that illuminance is not enough to ensure good quality lighting (SLL 2012)

simply providing that illuminance is not enough to ensure good quality lighting (SLL 2012)

Light is the visible part of the electromagnetic spectrum The main source of our natural light is the sun, which has a core temperature of approximately 10,000,000 Kelvin (K) Kelvin is Celsius + 273

380 nm 720 nm

En e rg y l e v e l s a n d co l o u r d i s tri b u ti o n Fig. 1.1b Electromagnetic Spectrum U l tra Vi o l e t 3 8 0 n m 7 2 0 n m Vi o l e t In d i g o B l u e Gre e n Y e l l o wora n g e R e d In fra R e d

Is the ability of a light source to render colours accurately. For example, under certain street lights (SOX) it is difficult to distinguish different coloured cars at night. Therefore, SOX lamps have bad colour rendering in comparison to metal halide lamps which have a good colour rendering.

In 1965 the International Commission on Illumination (CIE) introduced the Colour Rendering Index (CRI). The light source is scored out of 100 Colour Rendering Group (CRG) 1A 90 100 1B 80 89 2 60 79 3 40-59 Table: Colour Rendering Groups Colour Rendering Index (CRI)

CRI

Efficiency for lamps Efficiency = Output Input Efficacy = lumen output Watts

Watts Lumens

Metal halide lamp Lumen output: 20,000lm Watts: 250W Therefore: Efficacy = 20,000 = 80 lm / W 250

Metal halide lamp Lumen output: 27,000lm Watts: 250W Therefore: Efficacy = 27,000 = 108 lm / W 250

Illuminating Engineering Society

Stroboscopic effect is the visual phenomenon where by rotating machinery may appear to look stationary

Split luminaires over different phases Use high frequency ballast 28 khz approx. Use special luminaires Lead / lag

Incandescent Heat Discharge LED s Current flowing in gas Light emitting diodes

Light is emitted from a tungsten filament operating at a very high temperature inside a glass bulb. The temperature of the filament is very high (2800K) Approximately 10% of the energy used is emitted as light - hence its inefficiency.

Standard domestic lamp - 40 W, 60 W, 100W (BC, ES) Tungsten halogen - Security lights, 150W, 300W, 500W Spots lights - 12 V dichroic, GU 10

Sodium High Pressure (SON) Sodium Low pressure (SOX) Metal Halide (MBI) Mercury High Pressure (MB)

Low Pressure Mercury Vapour (LPMV) (Fluorescent) Compact Fluorescent Lamps (CFL s) Induction Neon

Efficacy: 50 120 lm / W Colour rendering: Good Lamp colour: Golden yellow Control gear: Ballast, ignitor, capacitor Run up time: 5 minutes (approx) Application: High bay, street lighting, architectural lighting

SON lighting

Elliptical Tubular

Efficacy: 100 180 lm / W Colour rendering: Very poor Lamp colour: Orange / yellow Control gear: Auto-transformer, ignitor, capacitor Run up time: 10 minutes (approx) Application: Street lighting

Street light 55 W Must burn horizontally

Efficacy: 70 90 lm / W Colour rendering: Very good Lamp colour: White Control gear: Ballast, ignitor, capacitor Run up time: 4 minutes (approx) Application: Stadia, high bay, retail

MBI lighting

Tubular Elliptical Double ended Pod

Commonly MBF (fluorescent coating) Efficacy: 40 60 lm / W Colour rendering: Average - Poor Lamp colour: Bluish / Whitish Control gear: Ballast, ignitor, capacitor Run up time: 5 minutes (approx) Application: Street lighting, replaced by MBI

Mercury High Pressure Fluorescent coating Tungsten filament No control gear needed Good colour rendering Efficacy 10 20 lm / W

Efficacy: 40 105 lm / W Colour rendering: Depends on lamp colour Lamp colour: Tri-phosphor, cool, warm Control gear: Ballast, starter, capacitor Run up time: Instant Application: Office, retail

T12 T8 T5

CFL s are being used widely for the replacement of GLS lamps massive savings in energy costs Improvements in technology - Shorter run up time - Dimmable Reduction in manufacturing cost

Internal electronic equipment Typical CFL s

Will they change the lighting design of the future? Low energy consumption Long life Electronic control gear within lamp Expensive for how long?

A company is replacing 500, 100 W incandescent lamps (1,000 hour life, cost 0.30 cent) with 23 W CFL s (8,000 hour life, cost 2.50 euro). Compare the costs for a lighting period of 8,000 hours, with an electricity cost of 0.11 cent per kwhr. The calculation should include the cost of purchasing the lamps.

500 lamps, CFL s last 8 times longer Incandescent lamps: To buy: 8 x 500 x 0.3 = 1,200 euro To run: 500 x 0.1 kw x 8,000 hrs x 0.11 = 44,000 euro Total cost: 45,200 euro

CFL s: To buy: 500 x 2.5 = 1,250 euro To run: 500 x 0.023 kw x 8,000 hrs x 0.11 = 10,120 euro Total cost: 11,370 euro Saving: 45,200 11,370 = 33,830 euro

A company is replacing 400, 100 W incandescent lamps (1,000 hour life, cost 0.40 cent) with 9 W LED s (20,000 hour life, cost 20 euro). Compare the costs for a lighting period of 20,000 hours, with an electricity cost of 0.16 cent per kwhr. The calculation should include the cost of purchasing the lamps.

400 lamps, LED s last 20 times longer Incandescent lamps: To buy: 20 x 400 x 0.4 = 3,200 euro To run: 400 x 0.1 kw x 20,000 hrs x 0.16 = 128,000 euro Total cost: 131,200 euro

LED s: To buy: 400 x 20 = 8,000 euro To run: 400 x 0.009 kw x 20,000 hrs x 0.16 = 11,520 euro Total cost: 19,520 euro Saving: 131,200 19,520 = 111,680 euro

An induction coil is located in a lamps Low energy consumption 50 % less Long life 5 years 100,000 hrs Good colour rendering Low heat output New technology come back! Instant illumination / re-strike

How does it work? It is a modified fluorescent lamp / but very different no electrodes The induction coil produces a strong magnetic field which excites the mercury Thus, creating UV light which is converted via the phosphor coating

Mainly used for signage Operates at 10 kv Must use Fire person switch Colour is determined by gas Tube is shaped to suit

Exploration and extraction of raw materials Transformation into materials Production Packaging Use Waste Disposal