How to read CFL packaging

Compact fluorescent lamp packets have useful information on them. Here's what it all means.

1. Base type. Bayonet or screw fitting.
   
2. Colour temperature (K). How warm-yellow (2700-3000K) or cool-blue (4000-6500K) the white is.
   
3. Light output. How "bright" the bulb is, measured in Lumens.
   
4. Wattage. The amount of power the bulb uses. The higher the power, the more the bulb costs to run.
   
5. Lifetime. The number of hours the bulb should last.
   
6. Mercury (mg). The amount of mercury the bulb contains.
   
7. Light efficiency (efficacy - lm/W). How efficiently the bulb converts electricity into light.
   
8. Incandescent equivalent. The wattage of the incandescent (traditional) bulb that emits the same amount of light.
   
9. Volts. The voltage the bulb is designed to work with. NZ has 230Volts.
   
10. Dimmable. Can the bulb be used with a dimmer or other electronic switches?
    

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