If you’ve ever walked into a room and felt instantly comfortable, chances are it has something to do with the lighting. And while we spend a lot of thought on the type of lights a room requires - layering overhead spots, pendants, wall diffusers and task lamps - we don’t often spend as much time considering the all-important light source: the bulb.
Changes in regulations over recent years have also made the decision process for buying bulbs more complex than previously when the choice was simply between an energy-guzzling 40 or 60 watt, incandescent lightbulb.
Today, we have three options and each has distinct characteristics.
LEDs (Light Emitting Diode) bulbs cost less to run, produce less heat and last much longer than other bulbs. And while they are initially expensive to buy, they can last up to 25 years (compared to the two-year lifespan of a halogen bulb). They are great for accent lighting as running a whole room at a decent brightness on LEDs can be expensive - though prices are constantly improving. They give a clean, natural light and are 100% recyclable.
CFLs (compact florescent lights) or energy-saving bulbs are a glass tube bent into a regular bulb shape. They are less expensive than LEDs but can take time to warm up to full brightness when first switched on. They come in various shapes and sizes and use about a third of the electricity of the old incandescent bulbs. The light they emit is sometimes considered a harsher white light than LEDs and not many of them can be dimmed.
Halogens are the cheapest option but have a shorter lifespan and give off a warm, bright light as soon as they are turned on. They work in a similar way to the old-fashioned incandescent bulbs, using a filament enclosed in a halogen gas to produce light, so consequently they can get very hot. However, they are now being phased out across Europe, to be replaced with the more environmentally friendly - and safer - LEDs.
But its not just the type of bulb that you need to decide on. There are also scales of brightness (lumens or watts) and colour of light (measured on the Kelvin scale) to be considered.
Lumens are a measure of the brightness of the light, the higher the lumens number, the brighter the light. Previously the strength of light was measured in watts but since the arrival of energy-saving bulbs this is less useful as they don’t use as much power. So watts have given way to lumens. As a rough guide, your bedside lamp should be about 400 lumens but you might want about 1500-3000 lumens in total to light up a sitting room.
This scale measures the colour - or temperature - of the light, or, in other words, how cool or warm it is. It is a key factor in affecting the mood of a room, so its important to consider what level of kelvins you want - too high and your comfy sitting room might feel more like a corporate office. Lower kelvins generate a cosy, yellow light that work well for sitting rooms, dining rooms and bedrooms, while higher kelvins give a more energising, cool blue light which is better for activity areas such as kitchens and bathrooms. As a comparison, the old incandescent bulb registered about 2,700 on the kelvin scale and gave a warm, yellowy light, while the midday sun is 5,500k and a candle is around 1,600k.
And finally there is a measure of quality of light, the CRI or Colour Rendering Index which measures the bulb’s ability to accurately represent different colours, or ensure that a bright red tomato looks bright red and not pale or dusty red. The index works with 100 being the best representation of colour and traditional incandescent and halogen bulbs score in the high 90s, while LEDs and CFLS score more in the mid 80s. Anything above 80 is considered accurate but if you wanted to highlight a painting or pick out a particular surface detail, you might want to look for a bulb with a higher CRI value.
So, just as it is important to include different lighting options within one room, it is also important to vary the light quality within spaces, depending on the mood you want to create, the activities taking place and time of day the room will be most used. Yes, it takes a little planning but it is most definitely worth it - and can be the difference between a room feeling can’t-put-your-finger-on-it uncomfortable or perfectly right.