Lighting and Health Guide

Introduction

From the moment we are born, light plays a very important part in our lives. Whether we are very young or in our twilight years, good lighting is essential. There has been much research into how lighting affects how we feel and there is good evidence to suggest that how we light out homes has a direct bearing on our health and well-being.

In this article, I intend to simplify lighting techniques to enable the reader to make an informed choice when choosing fittings and to identify best practice in relation to an overall lighting schem

Light and lighting – what’s the difference?

Light already exists in natural daylight given by the sun. Light is brought into the home through windows, glazed door panels and sun pipes to name a few. We also create light by the use of a multitude of different lamps and light bulbs. Even the humble candle creates light.

The best example I can think of is the theatre. They use light to excellent effect to create effects and draw your attention to a particular event. They use it to create moods and evoke emotions such as fear, surprise and elation. The use of the light is one thing, how they use it is lighting.

Can lighting really affect how we feel?

Imagine you work in a windowless office with very poor light. Your job entails reading and writing reports and administrative work. How would you feel? It is likely that you would suffer from eyestrain; mood swings and have frequent headaches. It is unlikely that this would ever be allowed to happen, as regulations would forbid it, yet there are no regulations covering such activities in the home. Similarly, if you were trying to create the right atmosphere to get a good nights sleep, I am sure that you would not install a 500w floodlight in the bedroom? These are extreme examples but show just how important light can be in our everyday lives.

It has long been recognised that our mood changes throughout autumn and into the winter months. We feel more lethargic and generally less inclined to be energetic and enthusiastic. Many studies have been done by medical professionals, who agree that there is a definite change in our outlook during the winter. It has been established that this mood change is directly liked to fewer hours and lesser quality daylight.

We have all heard the saying ‘It’s the winter blues’ but for some people, it is more severe and can result in Seasonal Affective Disorder (SAD).

Lighting requirements

I am sometimes surprised at how little thought and planning goes into some schemes. I have had customers who have spent many thousands on a new kitchen yet have no budget for the lighting. Similarly there are some who come to us shortly after having a complete bathroom refit looking for lighting and advice. Surely this should be planned in at the beginning so that cables and switches can be installed during the project?

Not everyone will have the same lighting requirements. For example, older people will often require a much brighter environment due to deteriorating eyesight. For people who cannot see well, even simple tasks such as reading, cooking, sewing or reading a food label can become almost impossible without good lighting.

A north facing room will require very different lighting requirements to a south facing room. A breakfast room or kitchen that gets sunlight first thing in the morning and a dining room that gets evening sunshine are to be prized and will have differing lighting requirements.

Safety is another important factor, particularly in the kitchen. Worktops should be well lit directly from above to avoid you standing in shadows. A very sharp knife, a tomato and deep shadows do not make for a very safe environment.

Lighting and moods

It has already been well established that different colours have a marked effect on how we feel. Choosing the correct colour for our environment has long been recognised as an important part of home design. There is also no doubt that different lighting effects affect our moods. How many of us would plan a romantic evening under the glare of ten 50w spotlights? The question is, does lighting create the mood or does the mood create the lighting? I believe it’s probably a little of each. So, how can we ensure that we have a variety of different lighting options to create the mood we desire? It simply cannot be done with one main source of light.

Lighting effects to avoid

• Harsh light can make you feel edgy and uncomfortable and prevent you sleeping.
• Direct glare, from a bare light bulb for example can cause headaches.
• Very bright ceiling fittings against very dark ceilings can cause depression.
• Poor lighting when performing tasks such as reading or sewing can cause migraines.
• Dark environments can lead to depression and lethargy.

Desirable lighting effects

• Use indirect lighting, this avoids glare and can give soft uniformed light throughout the whole room. It avoids shadows and seems a lot brighter than a single light source.
• Always diffuse fluorescent light. Consider using concealed fluorescent light around the edges of a room. This will wash the walls with light and create a near perfect lighting environment. This is particularly effective when combined with neutral light coloured walls.
• A good lighting contrast between each area of your home to avoid moving from a very dark space to a very bright space.
• Use multiple light sources if possible. Table lamps, floor lamps and wall lights can be used well to avoid shadows and create the correct mood.
• The use of dimmers enables you to balance light levels according to the activity.
• Place more light next to whatever task you are performing. If you are sewing or writing place a shaded desk lamp opposite. This will avoid shadows and prevent glare.
• In kitchens, ensure that downlights over work surfaces are in front of you and shine directly on the work area. This avoids you creating shadows by standing in front of the light source.

Energy Efficient Lighting

If I asked the question ‘what is energy efficient lighting’, most of you would reply ‘fluorescent lighting’? This simply is not true. Energy efficient lighting is simply the most efficient lighting for a particular application. Clearly you cannot illuminate a football field using fluorescent lamps, but you can light it well by finding the most efficient lighting for that application.

Today, there are more choices than ever for energy efficient lighting. Energy saving lamps and dedicated energy saving fittings are the two best known. Some are dimmable, however they are expensive to purchase and at the moment there is not a great deal of choice. I am sure that more will become available with time and the prices will fall.

Energy saving halogen lamps are now available to fill the gap left by the phasing out of the incandescent light bulb. There is a seperate article entitled No more ordinary light bulbs – what now? This article goes into more detail.

The last energy efficient category is LED. These have seen a huge rise in popularity recently and provide the most efficient light source available today.

Energy saving lamps

Light output is measured in lux or lumen, not watts. The humble traditional light bulb (GLS lamp) gives around 14 lumen per watt (lm/w). I only mention this as a reference point for the rest of this article.

There is good evidence available to suggest that the energy saving compact fluorescent lamp (CFL) can cause headaches and migraines. This is thought to be as a result of high frequency flicker that many of these lamps emit. However, we need to understand what alternatives are available to us today and what improvements have been made within the industry.

The CFL gives around 55 – 70 lm/w, 4 times as much as an incandescent lamp and lasts around 10 times longer. This represents a 75% energy saving over an incandescent light bulb.

Fluorescent tubes are even more efficient at between 80 – 100 lm/w making them 6 – 7 times more efficient than a GLS lamp. In addition, more and more fluorescent lamps are now tri-phosphor coated. This improves the colour of the light they emit making them much easier on the human eye.

Energy saving lamps need not have a detrimental affect on our environment if we follow a few basic rules.

• Use CFL’s in table and floor lamps only when they have a diffuser or shade.
• Always diffuse CFL’s. Many fittings such as downlights and spotlights have an optional diffuser or have a diffuser built in.
• Never use bare CFL’s as they can result in headaches and migraines for some people.

Energy saving halogen light bulbs

If you have a traditional chandelier or other light fitting where the lamp is visible then by far the best alternative is the energy saving halogen light bulb. These perform in exactly the same way as an incandescent light bulb whilst saving 30% in energy consumption. They give instant light, are fully dimmable, have no mercury content to worry about and give an excellent crisp white light. In addition, they last at least twice as long as a traditional household lamp, look the same and have a lower purchase price than a CFL lamp, typically between £1.40 and £1.80 each. It is likely that this cost will come down as demand increases.

Dedicated energy saving fittings

Gone are the days of flicker, flicker and ping buzz buzz when a fluorescent light fitting came on. In the early days these fittings came with magnetic ballasts that were not very efficient, caused a buzz and made the light flicker. They were exceedingly ugly and most often used in the garage or utility room. Fluorescent fittings are now available in many contemporary and modern styles to complement almost every type of environment.

Today, dedicated low energy fittings have a more efficient electronic ballast fitted. As a result, the poor light quality, hum, buzz and flicker have now been virtually eliminated, resulting in a very efficient and highly desirable light source.

Unfortunately, as with many things, people disregard this type of fitting because of bad past experiences. The truth is that there is almost nothing that gives a better overall light source than a modern fluorescent strip fitting, particularly in the kitchen.

A few basic rules will ensure you get the best available.

• Ensure that your fitting has an electronic ballast installed.
• Always diffuse the light.
• Never use bare dedicated low energy light sources.

LED

LED’s have no breakable parts and are ultra reliable. They are easily dimmable and come in a wide variety of colours. they are extremely efficient, typically 90% and getting more efficient all of the time. Good quality LED’s will give over 100 lm/w and that is set to rise to 150 lm/w by 2012.

Replacement LED light bulbs are now widely available. They have extremely low energy consumption, give off high quality light and last for over 35,000 hours.

Dedicated LED fittings are mainly confined to downlights and decorative outdoor fittings. There are now LED recessed luminaires available to the commercial markets. It is only a matter of time before a wide variety of LED fittings become available for use within the home.

The light spectrum

With the exception of the GLS lamp, many light bulbs today are available in different colour temperatures. The colour of light is measured against the Kelvin scale but what does it all mean? What is the difference between 3500k and 5200k? I will explain the difference and how it can affect our environment.

As a guide, the lower the number, the more yellow the light output. Very high colour temperatures take us into the blue spectrum. For the purpose of home, domestic and garden lighting, we need to concentrate on 2000k – 6500k. Lamps can be broken down into a number of main categories. Although they are available outside the below colour ranges, the majority will fall within these limits.

• 1200k – 1500k = candle flame.
• 1800k – 2400k = sunrise and sunset.
• 2800k – 3200k = incandescent light bulb.
• 2800k – 3500k = warm white fluorescent or LED.
• 4200k – 4800k = cool white fluorescent or LED.
• 6000k – 6500k = noon daylight.
• 6000k – 6500k = daylight fluorescent or LED.
• 6500k – 1000k = HID and LED.

Clearly then, if we are trying to create a romantic mood then the light needs to be in the 1200k – 2400k spectrum, (candle light and sunset) whilst if we are undertaking a task we should have as near to daylight as possible, around 5000k – 6000k. There a few basic colour temperature rules that you should follow.

• Avoid high colour temperatures when relaxing.
• Create a romantic and relaxing environment by using low colour temperatures.
• Use high colour temperatures for task lighting. Daylight bulbs are available for this very purpose.
• Use higher colour temperatures in the kitchen and bathroom where a crisp white light is required or desirable.
• Use higher coloured temperatures in any work space to avoid eye strain.

Next time you go looking for a light bulb, consider colour temperature in addition to type and wattage.

Conclusion

As you can see, the differences between light and lighting are considerable. There are many lighting factors that can have a positive and negative impact on our health. With a little care and consideration we can make the environment in which we live a safer, more relaxed, focused and pleasurable place to be no matter what the activity.

Today, you have more choice than ever when choosing home lighting. I hope this article has given you more information in order for you to make a more informed choice.

If you have any questions in relation to this article or require any further information please contact us.