Here we summarize the key features of the main types of low-energy light bulbs now available for domestic situations.
These work on same principle as fluorescent strip lighting, and contain an integral electronic ballast, which regulates current flow through the fluorescent tube.
Environmental: contain small amounts of mercury vapour inside the tube - no more than 5 milligrams, and in some designs less than 1 mg. Broken or obsolete bulbs should be disposed of appropriately (see Disposal of low-energy light bulbs).
A 20 watt CFL with remote-controlled built-in dimming mechanism that works in a standard light fitting.
A profusion of new designs and fittings mean that LEDs can now be used in virtually every application in the home, office or factory. They are produced in a huge variety of forms, from flexible self-adhesive strips to flat panel units for ceilings. There are even LED floodlights with a claimed life of 50,000 hours that will replace 150 W halogen units. Note that both low-voltage DC and 240 volt AC versions are available, so make sure you have the correct type for your fitting.
Light quality: earlier designs gave a 'cool' white light, but 'warm' tones increasingly available; also, various single colours, and sequential multicoloured giving a mini light show, with remote control!
Styles: reflectors most common, but new designs include LED clear or frosted globes and candles, LED filament bulbs, cove and panel lighting to replace fluorescent units, and self-adhesive strip lighting.
Environmental: contain no mercury, although LED semiconductors may contain small amounts of lead, nickel, arsenic and other potentially toxic metals.
Viribright 8W dimmable 'warm white' LED bulb.
The aluminium casing gives direction to the 500 lumen light output.
Consist of a tungsten filament surrounded by inert gas plus traces of a halogen such as iodine or bromine. Standard halogen bulbs are only slightly more efficient than the old tungsten filament bulbs, whereas the energy-efficient versions use about 30% less energy than standard halogen bulbs. Halogen bulbs are commonly used for spotlights and downlighters; but why not try the much more efficient LED equivalents?
Use a gloved hand to manipulate the glass envelope to avoid damaging the bulb, unless enclosed in a second glass globe (as pictured here).
NOTE: Sale of halogen directional bulbs (downlighters and spotlights) was banned in September 2016. Halogen GLS bulbs are banned from September 2018, leaving only specialist spotlight and floodlight halogen bulbs on sale.
These are the bulbs in the 'strip lights' familiar in commercial premises but also used in certain settings around the home, such as kitchens, utility areas, and above the bathroom mirror. They work on the same principle as compact fluorescent lamps (CFLs) but traditionally do not have an integral ballast. Hence they require a special fitting with ballast. Besides giving a typically bright light they have relatively low running costs and a long life. Like CFLs, however, they contain mercury and must be disposed of carefully.
Linear LED equivalents are now available that will simply 'plug and play' in the original fitting. These provide all the benefits of LEDs, including lower running costs, instant startup, and longer life, compared to traditional LFLs.