LIGHTING
 

This page concentrates on LED lighting.

Alternatives to LED lighting

Fluorescent tubes (commonly used in offices and shops) are sometimes known as 'florries'.

Halogen lights are usually bromide, chlorine or iodine-filled, and are commonly used in larger spaces such as sports halls and outdoors.

Benefits of LEDs

LEDs are resistant to heat, cold, shock and vibration and are easy to waterproof.

The ability to have on/off cycles with less degradation than normal bulbs results in a long life span (commonly between 50- and 100- thousand hours).

As well as being cost effective, this longer life span reduces waste and means lower maintenance (less replacing bulbs in hard to reach places).

LEDs don't require harmful mercury or lead (unlike fluorescents) and don't require bromine, chlorine or iodine (unlike halogens).

LEDs produce virtually no heat, which brings a number of further benefits: -

• Reduces cooling requirements
• Better for use near perishable food items (such as in fridges, kitchens and shops)
• Safer for use around children
• Safer for use around enclosed fittings or close to delicate lampshades - no more scorch marks

Although LED lamps are currently being manufactured in a narrow range of colours and brightness, they have the potential for great flexibility: -

• Don’t change colour when dimmed (n.b. dimming circuits damage most LED lamps at present - consult your supplier)
• Instantly reach full brightness (unlike than CFL or halogens)
• Accurate colour

Finally, LEDs require no starter/electronic control gear (ECG) which means they can be smaller and more discreet. You may, however, need a transformer if you are using foreign bulbs.

Lamp shapes

As there are many smaller LED units per one lamp, they can be arranged in different ways.

• Bulb
• Candle
• Cluster
• Golfball
• Honeycomb
• PAR (parabolic reflector can)/spotlight
• Strip

Fittings

LED lamps come in a range of standard fittings.

• Bayonet Cap (B22/BC) - 22mm
• Small Bayonet Cap (B15/SBC) - 15mm
• Edison Screw (E27/ES) - 27mm
• Small Edison Screw (E14/SES) - 14mm

Power guide

Light output is measured in lumens or candela. The output of LED lamps depends greatly on the angle spread (e.g. a spotlight versus a 360 degree or honeycomb bulb).

The following are merely guidelines for 360 degree spread.

• 100W incandescent ~ 15-18W LED (1700 lumens)
• 70W incandescent ~ 9W (1100 lumens)
• 60W incandescent ~ 5-8W (850 lumens)
• 40W incandescent ~ 3-5W (500 lumens)
• 20W incandescent ~ 2-3W (200 lumens)
• 10W incandescent ~ 1W (30 lumens)

• Incandescent: 15 lumens per Watt
• CFL: 70 lumens per Watt
• LED: 100 lumens per Watt

Lifetime

Most lamps come in standard and 'long life' versions which differ in price.

• Incandescent: 1-3.5k hours
• Halogen: 1.5-6k hours
• CFL: 3-15k hours
• Fluorescent Tube: 8-20k hours
• LED: 50-100k hours

Colour

Lamp colour is measured in degrees Kelvin (K). The lower the colour temperature, the 'warmer' the colour. The following are rough guidelines.

Atmosphere

• Warm/soft: <2,700K
• White/Bright: 2,900-3,000K
• Cool: 4,000K
• Daylight: >5,000K

Technical Ranges

• Incandescent light bulb: 2,700K
• Halogen: 3,000K
• Fluorescent: 2,700-6,500K

Source: Wikimedia Commons

Left to right:

1. CFL: 13W, 6500 K
2. Incandescent: 60W Extra Soft White
3. CFL: 15W, 2644 K
4. CFL: 14W, 3000 K

Supplier Location

A closer supplier will save time, money and impact on the environment.

Price

Naturally, price is also an important factor as you may be able to achieve a lower impact upon the environment or better improvements to health by investing elsewhere.

If anybody has any good UK suppliers, please do add a comment!

Sources

http://www.lightbulbs-direct.com/articles.asp

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