It’s summer and there’s light all around us – we take it for granted until those dark winter months come along. The sheer lack of sunlight can be depressing. Every year we experience this longing for summer, craving those long, bright days when we feel energetic and in a good mood. The sad news is, we’ve again passed the longest day of 2015, but the good news is that the right artificial lighting in your workplace can help you through.

Good lighting creates pleasant working conditions in a functional and atmospheric way. Satisfaction and efficiency will improve if you make sure you have enough daylight intake and a well-lit office space. Plus, your productivity will be positively affected by well-designed illumination. Artificial lighting that does not just help you see, but also meets your biological lighting needs, is the future of office lighting.

Here are six lighting hacks to keep you healthy and alert through those dark winter days.

1    Create atmospheres where your ideas can develop

We’re all attracted to light, and there isn’t any other medium that has as big an influence on our bodies and minds as light. Both daylight and artificial light play a key role in our health and wellbeing.

In companies with a high standard of interior design, productivity can increase”

Increasingly, companies face the question of how they can improve staff wellbeing and create a dynamic, creative and motivating environment. The design of the office space plays a vital role, as evidenced by a study from Germany’s Fraunhofer Institute for Industrial Engineering. The research shows that in companies with a high standard of interior design, productivity can increase by up to 36 per cent. Who wouldn’t like to see their efficiency skyrocket?

Additionally, comprehensive research from the Light Right Consortium, came to the conclusion that light increases productivity.

Only around 70 per cent of the interviewees stated that working at workstations with purely downward lighting was comfortable. In comparison, 91 per cent found a lighting atmosphere with direct/indirect lighting and a high quantity of vertical lit surfaces pleasing. Moreover, if the desk light is individually controllable, people feel motivated and work with greater accuracy.

TIP: Create a lighting atmosphere with direct and indirect lighting. Avoid having only downwards-directed illumination

2    Light for people, not just tasks

Lighting is often just seen as a necessity to enable us to see, but in fact it has many more qualities than the obvious ones. We should move away from just thinking of lighting for tasks and focus on creating light settings for people. Today, most people work indoors, and spends almost the entire day inside, in an unnaturally dark setting. Our light intake is responsible for sleeping and feeling well, and affects our productivity. When there is a lack of natural light to help us tell the time of day, then our circadian rhythm (body clock) loses its pace, with tiredness and listlessness as a result.

Light sets the mood / Photo: Vanessa Pedroso

We constantly find ourselves surrounded by light. It is much more than just illumination. It inspires, attracts, enables communication, sets a mood, and has emotional qualities. When this knowledge transcends into our built environment, pleasant atmospheres are created. Think of a visit to a theatre, a restaurant, or nightclub. These experiences are shaped by light. Good lighting enhances the mood and desirability of spaces, consequently contributing to people’s sense of wellbeing. Every building and space expresses and communicates an identity, and sometimes also a corporate value. Good lighting should be a part of this, because what other component can enhance an atmosphere as much as light can?

TIP: Create a mixture of different lighting. This will guarantee flexible change of light setting. Use illumination that supports a space’s identity

3    From homo sapiens to homo officunus

In today’s world, we spend many hours working in biotopes – surroundings created by humans”

In today’s world, we spend many hours working in biotopes – surroundings created by humans. Instead of trying to adapt ourselves to our creations, we should adapt these biotopes to our needs. Sufficient light is one of those needs.

So how can you create a setting that increases your satisfaction and productivity? Here are a few guidelines:

• Take the biological quality of lighting into account. Light synchronises the circadian rhythm. It influences our sleep-wake cycle and this has a big influence on our health and productivity.
• Adapt the lighting to the daytime and season, as well as to the individual needs of the user.
• Vertical surface illumination, preferably on large wall surfaces, is vital to create a sense of space and depth. It also gives a visual resting point for the eyes and adds a pleasant atmosphere to the working environment.

Too often, office environments are insufficiently lit, not only from the perspective of biological lighting needs but also from an architectural one, where the room feels smaller due to inadequate lighting.

The graph below shows how office workers assessed their working environments – showing which aspects are important to them and how satisfied they are with each aspect. As you can see, lighting is rated the most important of all the aspects mentioned, but there’s plenty of room for it to improve.

Data based on a study from Sedus together with the research institute Hagstotz ITM

TIP: Have a light for general illumination, a standing luminaire that uplights the ceiling and a desk light

4    Get the best spot in the house

Are you based in a co-working space? And is there a flexible desk policy? Choosing the right spot in the house can go a long way.

Pick a place with a lot of daylight. It is recommended that around three per cent daylight reaches a person’s working area. However, in most offices this is not the case. Daylight gives an emotional quality to a space and the possibility to look outside is an added bonus. If you can, choose a spot near the window. But make sure that there is sun shading to prevent harsh reflections on your computer screen.

TIP: Take the window seat, north, east or west facing

5    Light against the blues

About 80 per cent of all information is taken in through our eyes. Until recently it was believed that our eyes used two kinds of photoreceptors – rods and cones – to receive light, but a decade ago, a third kind, called ganglion cells, was discovered. Unlike rods and cones, these cells do not contribute directly to our sight; they are nevertheless light dependent and help to regulate our circadian rhythm. So light is not just a prerequisite for seeing, but is also an important zeitgeber (timer) and a regulator for our bodies.

Unfortunately, we often don’t get the light intake we actually need, especially during the darker time of the year, resulting in the winter blues or seasonal affective disorder (SAD) – a type of depression linked to a lack of light. It leaves people feeling moody and lacking energy. Most people who suffer from SAD benefit from bright light treatment. Even in a workplace setting, light therapy makes people feel more awake and energized. It is found that an illumination that goes up to 2000 lux at the working area in the morning and the afternoon, reduces the physiological reaction of stress and gives an energising effect to the body.

In comparison, most working areas are lit to a standard 500 lux. If you want to check the amount of lux at your desk, download a lux meter app. It’s not very precise, but it gives you an idea on how little light we actually have indoors.

Daylight (10000K) and sunset (2000K) / Photo: Sabine De Schutter

Not only is a higher quantity of light needed, but also the colour temperature of the lighting plays a role.

The artificial lighting should correspond to the colour temperature of the daylight. At noon the sky’s colour is a very cool 10000K but at sunset it is a much warmer 2000K. Additionally lighting should reflect indirectly into the eyes from large surfaces, such as walls and ceilings.

TIP: Try to catch enough daylight at any time of the year. Go outside for a break, get off a stop earlier from the subway and walk the rest of the way to the office. You should have at least half an hour of daylight a day

6    Light, coffee, action!

When you work late on a computer or tablet it can be difficult to sleep afterwards. The cause of this is the high blue content of backlit screens”

A deadline and still a lot of work ahead, no time to sleep! As lighting can disrupt your sleeping pattern, it can also boost your activity. If you have already followed the above-mentioned advice for biologically effective lighting than you’re already on the right path. If you need to pull an all-nighter, increase the light intensity and the quantity of bluish white light in the room. Almost done with your work? Change the setting to warm, low-intensity lighting, which will calm you down.

You might also have experienced that when you work late on a computer or tablet it is difficult to sleep afterwards. The cause of this is the high blue content of the backlit screens. Blue light at night causes an out-of-phase circadian rhythm, and is a health hazard. So use this lighting hack consciously. There are some applications you can install that correlate the screen’s brightness and colour, to the daylight of your location. F.lux, for example, works on most systems, or the Twilightapp reduces the amount of blue lighting on your Android phone.

TIP: Have different lamp types and colour temperatures at your working area. Warm light sources at your desk can be combined with indirect and general lighting with different colour temperatures, for example 3500K and 5000K

If your workspace is still lit using 4 x 18W recessed fluorescent units, you really ought to change them. There is a huge range of more efficient LED ceiling panels available. We have tested 10 panels from the cheapest and most cheerful to quality engineered units with sophisticated optics. We could easily have tested 10 more. We have tested both the thin flat panel (edge-lit) types and the deeper troffer types, which are backlit.

Unfortunately, there seems to be a race to the bottom in price. This, coupled with a lack of basic photometric data from some suppliers, has led to quite a few poor lighting installations. I speak to a lot of people who complain about glare, uneven light distribution, dark ceilings and areas in the office that don’t receive much light because the luminaires are arranged inefficiently.

Bright, white and gloomy

Obviously, a flush, recessed luminaire cannot project any light on to the ceiling – the ceiling won’t receive any direct light. So the workspace can look dark and gloomy even if the ceiling is white.

Incidentally, unless the floor and worktops are quite pale, your installation may not meet the minimum requirements of BS EN 12464-1. It is also unlikely to meet the British Council of Offices guidance, the SLL’s LG7 or the Code for Lighting. And frankly, dark ceilings are best avoided whether or not they comply.

Related to this, glare from the panels, seen against a dark ceiling, is exacerbated by the high lumen output (and hence, luminance) of some of these units. Many LED panels emit 50 per cent more light than the 4 x 18W fluorescent units they replace. More light doesn’t necessarily mean better lighting. One solution may be to dim the panels to save more energy. An alternative is to increase the light on the ceiling using extra uplighters.

To reduce the risk of glare, you need to ask the supplier for the maximum luminance (cd/m²) of the panel. We often assume that the workspace will have positive polarity screens. Common examples are word processing or spreadsheets where black lettering is seen against a white background. Here, the limit is 3,000cd/m². However, a lot of CAD and photo-manipulation software displays lines or text against a black or dark grey background and the maximum panel luminance for these areas is 1,500cd/m². Again, there are various solutions including dimming or using luminaires with good optical control. The guidance documents mentioned above give the luminance limits for various scenarios.

The manufacturers of all the luminaires we tested said the panels produce installations with a unified glare rating of less than 19. If you have any doubts, ask your supplier for the data to support their claim.

Finally, we seem wedded (in the UK at least) to fixing luminaires at 2.4 or 3m centres. How do you know that the panel you choose will not create dark areas across the workspace? It is difficult to tell from the sales and technical literature because, in most cases, the data isn’t provided. Technical information costs money to produce and that’s not the name of the game for many panel suppliers.

Proprietary software

The solution is to calculate the values across the whole space using proprietary software. But who is going to take time to do that if the only topic under discussion is price?

In our tests, we didn’t see much of a correlation between build quality, performance and price. Choose the panel that meets your lighting needs and those of your staff, and then look at the price.

The price ranges given are based on approximate end user prices for a quantity of 50 non-dimmable versions without emergency or PIR sensor options. The ranges are: £ <£80, ££ £80-160, £££ £160-240, ££££ >£240.

This market is viciously competitive but remember that energy cost savings from dimming the panel or a more efficient optic/light engine may well override any differences in the initial purchase price.

Nowadays, it’s nigh-on impossible to buy a luminaire from the DIY sheds or a high-street retailer which doesn’t have a GU10 cap. 12v lamps seem to have had their day as far as the mass retailers are concerned.

It isn’t difficult to match the light output of a 20W or 35W halogen GU10, so we have only tested LED lamps that claim equivalence to a 50W.

The European DIM2 regulation says that to make this claim, the LED GU10 lamp must emit more than 345 lm in a 90-degree cone. The total lumen output, including light that falls outside this cone, may be considerably higher. Some of the lamps tested emit over 500 lm so they would clearly be seen as an improvement if you retrofitted them in an existing installation of halogen GU10 (with the same beam width).

We’ve asked several experts, and our understanding is that all products currently on the market must conform to DIM2. But we regularly hear of lamps that don’t.

The problem for Joe Public is that some lamps don’t state on the box whether the lumen output quoted is the total emitted or within the 90-degree cone. Some quote both figures. Reputable manufacturers use phrases like ‘usable lumens’ or ’90-degree cone’ so you know what you are buying.  However, until all suppliers mark their packaging clearly, it is impossible for the purchaser to make fair comparisons between the different products. No wonder people buy the cheapest or the one quoting the biggest lumen value.

The situation is made worse because there is no effective policing of the market. This, in effect, benefits the poor quality, low-cost suppliers to the detriment of the manufacturers of good-quality lamps.

One last point to make is that a 90-degree cone isn’t really what you would call a spotlight. For the non-trigonometrists amongst you, that’s a two-metre wide illuminated patch from a lamp one metre away.

If you are as confused as I am by all the test standards that cover LEDs, there is a useful summary on the LIA website. Look for Technical Statement TS01. It’s nine pages long and covers existing and proposed European and US regulations and guidance.

None of the 11 lamps we’ve tested here had a particularly high power factor. The best was Osram at 0.88 and the poorest were the Aurora and Bell at 0.52. Why does this matter? Because it means that you are drawing more current than might be apparent from just looking at the wattage. An electrician complained to me about this because he had to resize all his fuses in a (large) domestic house purely because of equipment with a poor power factor.

Before you buy the lamps, you should check what the beam looks like. Some have coloured edges or don’t have a smooth gradation of light from the centre to the edge. The three on the left of the main photo for this article are all rated at 2700K and the one on the right is rated at 3000K.

Summary of results
We were pleased to see that, generally, the performance was as claimed. We measured the total light output.

Note that we tested just one lamp from each supplier. There are always tolerances in manufacturing and so the lamp you buy may not perform exactly as the one we tested. However, these lamps are made by the million; it would be surprising if they varied that much.

These lamps have a round ‘bulb’ and are designed to retrofit anywhere you would use a normal tungsten filament lamp. They are LED versions of what are often called GLS or A-line lamps. Some of the bulbs are frosted or opal and some have visible LED ‘filaments’. All the lamps claim to be dimmable.  

It is worth remembering that a 60W tungsten filament lamp produced about 700 lumens. This much light from a bare filament was usually considered to be too glaring and so people fitted lamp shades over them. Alternatively, the bulb was made with an opal or frosted finish to soften the effect.

Of course, the difference is found in the better efficacy. The average of the LEDs we tested was 95 lumens/W, compared with 10 lm – 12 lm/W for a standard tungsten lamp. That’s an 85 percent saving in energy.

We tried the lamps on two different dimmers. One was a traditional resistive load type of dimmer used for tungsten filament lamps. The other was a more sophisticated unit designed for retrofit LED lamps. The purpose of the test was simply to highlight whether there were likely to be any problems or, conversely, lamps which performed particularly well. We could not test every combination because there is such a wide range of dimmers on the market.

All the LED lamps worked well on both dimmers but this may be because we also had a 70W incandescent lamp in the circuit in order to make a fair visual comparison when dimmed.

These LED versions are designed as energy saving replacements for the original tungsten halogen filament lamps.   

These filament lamps were typically 25 – 50W whereas the LED versions are more often 2 – 4W. As a reminder, these G9 lamps have two, flat pin electrical contacts and run directly off the 230V mains supply.

An important point to consider when buying these LED lamps is the direction the light is emitted. A filament lights all the way round whereas these LEDs can emit light quite strongly in one direction but not in another. Some LEDs are mounted back to back on a flat circuit board which emits a lot of light in the 0°/180° plane but hardly anything in the 90°/270° direction or out of the front end of the lamp. Look at your light fitting to see where you want the direction of light to go.

Another aspect that might be important is the number of times you can switch it on and off. This is known as a switching cycle.  This can be important where the lamp is switched several times a day. Lamps controlled by movement sensors switch on and off much more frequently than a typical on in the morning and off in the evening regime.

There is a huge number of suppliers of LED versions of G9 lamps. We have chosen some of the better known names but the list is by no means complete. To make the comparisons similar, we have chosen non-dimmable lamps which are either 2,700K or 3,000K.

When comparing these lamps with an original incandescent one, it is worth remembering that a filament type G9 often produces striations and uneven uniformity when illuminating  a smooth surface. Many of the LED versions produced better results.

Thanks to the LED revolution and a change in the way we use computers and screens, there has been a shift towards installing slimline LED panels in offices.

These are usually 600 x 600mm to fit into existing ceiling systems and deliver 3000-4000lm with a much reduced energy consumption, making them an attractive proposition to many office managers.

It used to be that plastic diffusers, either prismatic or opal, were the standard method of controlling light distribution from fluorescent fixtures. This was the case until codes for lighting offices demanded better control over light distribution. Plastic panels were replaced by aluminium reflector systems – and the era of the cat 2 louvre was upon us.

In light of these changes there is now sufficient confusion about the fire-rating requirements of the diffusing material of a luminaire to warrant a review of the current situation.

There are three possible conditions for thermoplastic (TP) diffuser material.

1. No rating at all

This is the most serious condition. If a luminaire specification does not carry any information about the fire-rating of its diffuser, it’s best to assume that it has no rating and avoid it.

The section on thermoplastic materials in the Fire Safety Part B document could be more helpful than it is currently written, but the general interpretation for the use of thermoplastic diffusers is as follows:

Ceilings of rooms and circulation spaces (but not including protected stairways) may incorporate thermoplastic lighting diffusers if ALL of the following provisions are observed:

a. The surfaces of the void space above the suspended ceiling comply with the general provisions that apply to the space below the suspended ceiling
b. TP(a) diffusers can be used without restriction
c. TP(b) diffusers are restricted as detailed below.

In other words, there is no provision in the UK Building Regulations for the use of non-rated thermoplastic panels. The situation is confused, however, by the number of luminaires currently available that use non-rated thermoplastic diffusers. Lux spoke to the Lighting Industry Association, the largest trade association in Europe, who told us:

‘The LIA position is that it is not illegal to sell a panel that is neither TP(a) nor TP(b) rated as long as it is clearly stated in the installation instructions that it cannot be used if it forms part of a ceiling. Panels that form part of a ceiling (ie recessed) must be either TP(a) or TP(b) rated and be installed in accordance with the Part B regulations relating to that rating.’

So this is a case of caveat emptor (buyer beware). Unless the manufacturer’s information states clearly that the luminaire being offered contains a diffuser that complies with either a TP(a) or TP(b) rating, DO NOT BUY IT.

2. TP(a) rating

Thermoplastic materials undergo specific tests to certify their ability to withstand the application of heat and fire. The requirements are established by Building Regulations Approved Document B, which sets out the fire safety of buildings. Section B2 covers internal fire spread.

TP(a) usually relates to polycarbonate diffusers with a thickness of at least 3mm. The testing procedure requires that the material self-extinguishes and any flaming and afterglow must not exceed five seconds once the source of flame is removed.

There is no restriction on the use of TP(a)-rated diffuser material.

3. TP(b) rating

TP(b) materials tend to be acrylic or polystyrene. It is a more problematic material because its use is limited by the extent of the installation. The testing for TP(b) requires a flame to be presented to the material. If the material combusts, the spread of flame must be no more than 50mm per minute – that’s 12 minutes to completely blanket a 600mm wide panel.

How the restrictions work in practice is as follows. In circulation spaces, the total area of diffuser panels must not exceed 15 per cent of the total floor area. The maximum area of one diffuser, or group of diffusers, must not exceed 5m x 5m. There must be a 3m spacing between each 5m x 5m diffuser grouping.

Maximum and minimum spacings of TP(b) diffuser panels in circulation areas

In offices and other rooms, the total area of diffuser panels must not exceed 50 per cent of the total floor space. The maximum permissible area of a single diffuser panel must not exceed 5m2. (This is a big luminaire and is most likely to occur as a rooflight detail.)

Where a conventional arrangement of luminaires is used, then either the arrangement for circulation spaces should be employed or else spacing between all luminaires should be no less than twice the diagonal distance (or diameter) of the luminaires in use.

Maximum and minimum spacings of TP(b) diffuser panels in spaces other than circulation areas

TP(b) is a problematic material because it does catch fire, albeit in a ‘controlled’ manner. The total area of 5m2, for example, could be used to apply to a linear light channel measuring 100mm wide x 50m long. The material has the potential of spreading flame along its entire length over a period of only 20 minutes per metre. In a few hours, the lighting diffuser could spread its flame the length of an office corridor. This is a worrying prospect.