Is There a Problem with the Quality of Light From High Efficiency Bulbs?Tuesday 11th March 2014 04:33pm
The answer to the question of problematic light quality is a resounding “No”, but I do acknowledge that in the past there have been problems. Now, what most people consider to be problems with light quality are really issues stemming from the purchase of low quality bulbs, purchase of the wrong bulb wattage and confusion about how the colour of lighting can enhance or detract from the comfort and use of a space.
“But I Only Like Incandescent Bulbs”
In the early-days of high efficiency bulbs, there seemed to be a general dislike of the colour and brightness of fluorescent and LED bulbs. Some people felt that these bulbs made rooms look and feel cold and unappealing. Some people were convinced that fluorescent and LED bulbs made them appear tired or worn out and that the flickering ballasts on the fluorescent lights at work gave them headaches. Fortunately modern fluorescent and LED bulbs are available in an array of warm or cool tones to suit home and business use, and they don’t have the issues with flickering that are typical of the old-style fluorescent strip lighting.
One measure of light quality from a bulb is how accurately colours appear in the light of the bulb compared to natural sunlight. The Colour Rendering Index (CRI) measures how accurately a bulb replicates natural light source such as sunlight. CRI is measured from 0-100, with sunlight at 100. Bulbs with a CRI of more than 85 are really only necessary for photographers and commercial use, as they would make a casual living area feel more like an interrogation cell!
There are a few trade-offs with high-efficiency bulbs. For example, LED bulbs do not produce colour accuracy as well as incandescent or Fluorescent bulbs, but LED lights last far longer than either of the alternatives. High efficiency-to-cost and a median of around 65 -75 lumens per watt for LED bulbs more than make up for some colour inaccuracy. The shape of fluorescent bulbs isn’t as clean and sleek as that of incandescent bulbs, but the new compact bulb styles fit most lamps, so they are hidden from view. Fluorescent bulbs with a covering over their tube structure are available, too.
Choosing the Right Bulb
A large problem with high efficiency lights is confusion at the point of purchase. There are so many bulb types; what do the labels mean? The old system of knowing that x-number of watts means enough light to read by is gone, but do not fear, here are a few tips to make purchasing energy-efficient replacement bulbs much easier.
Since high efficiency lights use different amounts of energy, produce a different colour of light, and are listed as using a much lower wattage, it can be difficult to quickly choose a replacement for an incandescent bulb. A quick rule of thumb is to look for an output of 10 times the wattage of the bulb you are replacing, in lumens. For example, for a 40 watt bulb, choose a compact fluorescent light (CFL) or LED that produces at least 450 lumens.
For colour selection, many people prefer warm-toned bulbs for living rooms, bedrooms and other spaces where a relaxed feeling is required. Cooler or white-toned bulbs are usually preferred where people want to feel alert or need brighter lighting, such as workrooms, bathrooms, children's play areas and kitchens. Of course, personal-preference will always win, so select whichever bulb you feel complements the room, keeping in mind of how they affect lighting colour.