Light bulbs last updated: June 2017
In order to be featured on Topten, light bulb models must comply with European Commission Regulation 1194/2012 with regard to energy labelling of directional lamps, light emitting diode lamps and related equipment, as well as meeting the following criteria:
LED traditional shape (GLS) lamps:
- Energy rating of A+
- Luminous efficacy of over 75 lumens per Watt
LED candles and GU10 spotlights:
- Energy rating of A+
- Luminous efficacy of over 55 lumens per Watt
Inefficient model selection
The “inefficient model” is an anonymised halogen retrofit bulb equivalent to the most common output in each sub-category. This allows comparison with the least efficient technology available.
Annual energy consumption: the energy consumption, in kWh, per year based on 1,000 hours of use.
Annual running cost: the annual running cost in electricity for the product based on the quoted annual energy consumption and an electricity cost of 14.05p/kWh.
Colour temperature: the light colour appearance of a lamp can be defined in terms of its colour temperature in degrees Kelvin (K). There are three main colour groups: warm whites < 3300 K; neutral whites 3300 K - 5000 K and daylight whites > 5000 K.
Colour of light: the colour group of the bulb as defined above.
Dimmable: whether the bulb can be dimmed using a standard lightswitch or dimmer switch.
Energy label: the energy efficiency class according to the EU Energy Label. The classes range from A++ (most efficient) to E (least efficient).
Incandescent equivalent: the wattage of an equivalent incandescent bulb.
Life expectancy (hours): the number of hours the bulb is expected to last, defined as the point at which 50% of bulbs will have failed.
Luminous efficacy: the efficiency of the bulb in light output (lumens) per unit of power (watts). This is used to determine a lamp’s inclusion in Top10 and to rank the featured models.
Switching cycles: the number of times the lamp can be switched on and off before failure. According to Regulation (EC) No 244/2009, a switching cycle consist of a period comprising 1 minute on and 3 minutes off.
Wattage: the rated power consumption of the lamp in Watts.