What has improved?
Firstly, the technology is more compact making it possible to replace a standard GU10 halogen bulb commonly found in a spot/downlight fitting.
The number of lumens per watt has improved vastly meaning more light can be produced from a lower wattage bulb. The colour temperature or Kelvin rating helps determine the light output, the higher the ‘K’ rating, the cooler the light and the higher the lumens. This not only makes for a brighter light but it also has an effect on your bills. If you imagine 4 50w halogen bulbs burning away at 200w total, at current UK average electricity prices those bulbs alone will cost you £3.60 per month, whereas the same GU10s in LED at 5w will cost 36 pence.
What bulb types are available?
LED bulbs are now available in all the shapes and sizes you’d expect, GLS, candle, G9, MR16. The latest LED Filament bulbs are available in, globes, pygmys, golfballs, and squirrel cages. They are a revelation in that they look like a standard bulb but with no unsightly plastic collar around a large portion of the bulb. This allows light to be spread in all directions much like a normal incandescent bulb. This directly affects the lumen output as the light is not concentrated in one direction and spread over 360°.
You get what you pay for.
Don’t be tempted by the cheaper option, it really won’t pay dividends. Always go for the well known manufacturers that have established themselves in quality, they offer better lamp life, light efficacy (how well a source provides visible light), CRI (colour rendering index) and heat dissipation. Cheaper bulbs will fail because of heat when fitting in fire rated downlights and won’t give an accurate replication of some colours. A CRI rating of above 80 is good but the higher the better.
Do you want to dim?
Dimming LED is a mine field, just because a bulb says its dimmable doesn’t mean it will work. Common issues are flicker and cutting out. Cheaper bulbs are less likely to be compatible with standard dimmers. Until recently trailing edge dimmer have been recommended but nowadays decent LED specific dimmers are readily available. You’ll also need to consider minimum loads and the importance of de-rating dimmers so not to exceed maximum loads.
The best advice is to buy your dimmer and bulbs at the same time with advice from either the manufacturer or an experienced wholesaler. This will avoid costly mistakes associated with dimming.