A Guide To The Specification of LED Lighting Products- Part 2 of 4

System Reliability

Unlike lifetime based on luminaire maintenance, lifetime of the luminaire has to do with the reliability of the components of a LED luminaire as system.

Factors Affecting System Performance - LEDs

LEDs do not radiate heat however, in current products half or more of the input energy must be converted into heat that must be conducted away from diodes.

Factors Affecting System Performance - Optical

LEDs are directional light sources, giving the lamp designer new challenges in comparison to existing lamp technology.

The use of reflectors, lenses and diffusers allows a designer to direct light in many different ways.

The efficiency and depreciation of the optical system must be considered and factored into the overall efficiency of the luminaire. 

Factors Affecting System Performance- Mechanical

The mechanical integrity of a luminaire is important in several different areas including: IP rating to suit the application, heat sinking that will not become compromised with time, lack of maintenance vibration resistance so the heat sink does not become detached from the PCB, bonding mechanisms that are suitable for the life of the luminaire. 

Many LEDs and specifically phosphor can react to different chemicals. Some gaskets can out-gas chemicals which can affect the performance of some LEDs.

Factors Affecting System Performance- Cooling System

The performance of a LED is dependant on its temperature during operation.

The design of the luminaire will influence its operating temperature and hence published characteristics.

The paint finish or fixture colour may affect the heat dissipation from the luminaire.

A PCB is the interface between a LED and the heat sink and has a thermal resistance value. 

The higher the resistance the less efficient the system is at conducting away heat from the LED. 

This may well impact on the LED lumen output performance and ultimately its life.

Factors Affecting System Performance- Electronic

Electrical overstress is a cause of catastrophic failure of LEDs.

Some LEDs contain an on board Transient Voltage Suppression chip (TVS), which provides some level of protection.

A well designed lamp will feature the necessary design or protection in order to minimise damage at installation or power-up.

Failure rate of the external control gear shall be included in the overall assessment of total life/failure rate.

System Reliability

The entire system only lasts as long as the critical component with the shortest life, whether that critical component is a weather seal, an optical element, a LED, an electronic control gear circuit or something else.

LED light sources are simply one critical component among many, although they are often the most reliable component in the whole system.

How To Verify Lifetime Claims

In most cases, the reliability of LED luminaires is longer than the practical test times, verification of manufacturer’s life time claims need to be made in a sufficiently confident way.

In order to validate a lifetime claim, an extrapolation of test data is needed. There is no validated way to translate the lumen maintenance curve of an individual LED light source into a curve for the LED module or LED luminaire.

Beyond the 10,000 hours testing recommended by LM-80, statistical predictions are made. If LED light source data is available for 6000 hours, LED modules and LED luminaires may have life testing carried out for just 2000 hours!

A Guide to the Specification of LED Lighting Products - Part 1 of 4

Why Chose LED Lighting?

• LED lighting is transforming the lighting industry, driving manufacturers in exciting new directions.
• LED lighting has quickly superseded conventional lighting.
• LEDs offer long lifetimes, energy and maintenance savings, making them an efficient energy saving solution. 

What’s so great about LEDs?

• Unlike traditional lighting, LEDs provide millions of colours and dynamic effects meaning they are unrivalled in terms of design, scene-setting and ambience.
• Thanks to their miniaturized dimensions and low heat radiation, LEDs can be embedded almost anywhere!
• Due to their digital nature, LEDs can be programmed, offering an unlimited scope for creative use and effective energy management. 

Choosing the right LED

• This document aims to educate consumers about the Lighting Liaison Group’s universal quality criteria for LEDs.
• Using this criteria when selecting LED luminaires will allow you, the consumer, to judge manufacturers claims on an equal, like for like basis.
• Applying the suggested criteria to all your LED purchases will ensure your luminaire is right for you. It will also eliminate any disappointment upon installation.

Key Terms

• LED Die – The LED die or chip is a the fundamental light source
• LED Package – The LED died is contained in a suitable package allowing simplified electrical connection or assembly
• LED Module- This is the LED together with mechanical and optical component making a replaceable item for use in a luminaire
• LED Luminaire- This is the complete system 

What is LED lifetime?

• It is important to remember that lifetime claims based on lumen maintenance and luminaire life are two very different things. 
• Lifetime claims based on lumen maintenance refer to the lumen maintenance projections of the LED light sources integrated into that luminaire.
• Lifetime claims based on luminaire life are related to physical failures.

How is LED lifetime tested?

• Many LED manufacturers use the LM-80 method to measure lamp life. This requires testing of LED light sources for 6,000 hours but recommends testing for 10,000.
• It calls for testing three surface temperatures; 55°c, 85°c, and a third determined by the manufacturer. This means that users can see the effects of temperature on light output. The method also specifies additional test conditions to ensure consistent and comparable results.
• In practice, LED manufacturers test their products for 6,000-10,000 hours and then apply extrapolation methodologies to produce LED luminaire specific curves.

Example LM-80 Calculation 

Constraints on LED lifetime test results...

• There are differences in the results obtained from the LED die and those from the LED luminaire. This could be due to a number of issues including thermal management which can change the actual performance.
• Catastrophic failure modes of individual LEDs and other failure modes of light output depreciation are not taken into consideration.
• There is no valid way to translate the lumen maintenance curve of an individual LED light source into a curve for the LED luminaire.

New to The LED Specialist: Danlers RESLOADE

This latest addition to our stock is a resistive load designed to eliminate lamp instability and flicker which often occurs when non-resistive loads such as LED lamps are dimmed. This product is also compatible with compact fluorescent lamps and dimmable transformers which are prone to the same instability as LED lamps.

The RESLOADE is designed to be used with Danlers Grid trailing edge dimmers (DQDGD) when dimming LED lamps and any other use of this product will invalidate its warrantee. The RESLOADE must be connected to Earth. For direct mains dimmable lamps the RESLOADE is connected at a suitable light fitting, in parallel across the load, between the dimmed variable live and neutral. For mains dimmable transformers the RESLOADE is connected across the primary (variable mains input) side of the transformer.

The RESLOADE is designed to be placed in the ceiling void and can be passed through a 63mm diameter cut-out, the typical size for down lighters. The RESLOADE has an effective load of 10w and an operating temperature of approximately 40°c above ambient. It should be installed where air flow is not restricted. It should not be covered by insulating materials or positioned near any heat sources or heat sensitive objects. 

To purchase this or any other LED or electrical product visit our website http://theledspecialist.co.uk/ or call the office to speak to one of our informed lighting and electrical specialists 0118 939 3218 

Lightsave Fuller Read Lighting Project: River & Rowing Museum, Henley-on-Thames

Our sister company, Lightsave Fuller Read has helped the River & Rowing Museum reduce its energy costs and carbon emissions by replacing existing halogen light fittings with the latest LED light sources.

The LED switch-over is expected to reduce the River & Rowing Museum’s lighting energy expenditure by over £2000 per annum; the museum can also expect additional savings on their maintenance costs. It is expected the River & Rowing Museum will see a return on their initial investment in around three years (based solely on energy savings).

The River & Rowing Museum is located in the picturesque town of Henley-on-Thames and is one of the UK’s leading independent museums welcoming over 116,000 visitors a year. The museum is home to 20,000 items covering the international sport of rowing, the history of Henley-on-Thames, the story of the River Thames and the children’s book the Wind in the Willows. The vast collection includes objects, photographs, books, ephemera and archive material.

The focus of the lighting upgrade has been improving the energy performance in the museum’s three main galleries; the Schwarzenbach International Rowing Gallery, the Invesco Perpetual Henley Gallery and the River Gallery. In addition to this, the Lightsave Fuller Read team felt some of the smaller galleries would also benefit from being upgraded to LED lighting.

Andrew Brown the facilities manager said: “We are always looking for ways to improve our energy efficiency and the Trustees are very supportive of green initiatives. We had identified that upgrading to LED lamps would reduce lighting energy consumption; the team at Lightsave Fuller Read spent a lot of time with us testing a number of different lamps until we found the perfect solution. It was particularly important that the curators also had input to the selection process in order to ensure that factors such as colour balance and energy performance were considered.”

Philips Master LEDspot LV MR16

Alan Kilford, Managing Director of Lightsave Fuller Read added: “We helped the museum to set up trials of different lamps so they could evaluate the options available and select the best solutions based on a range of criteria. It was clear that Philips LED lamps would deliver on all of these requirements.”

The Schwarzenbach International Rowing Gallery, which is also used for hospitality events, was previously lit using 170 halogen downlights, with a mix of 20 watt and 35 watt lamps. These have now been replaced with Philips 4 watt Master LED MR16 lamps, allowing the original fixtures and light levels to be retained.

Philips Master LEDspot LV AR111

The other two main galleries have higher ceilings and so a higher light output is requires. They were originally lit using costly, 50 watt and 75 watt AR111 halogen lamps to achieve the required illuminance at floor level. At the recommendation of Lightsave Fuller Read, these lamps were replaced with around 100 Philips Master LED AR111, it is predicted this simple change will lead to huge savings in maintenance costs as Philips Master LEDs have a lamp life of 45,000 hours and therefore do not need to be replaced as often as their halogen counterparts meaning less time is spent fitting lamps at great height.

Andrew Brown concluded: “There has been a big improvement in light quality and the feedback from staff and visitors has been very positive. In addition to the energy savings, this project will reduce our CO² emissions by nearly 10,000 kg per annum.”

For more information on these or any other lighting products please visit our website http://theledspecialist.co.uk or call the office on 0118 939 3218 to speak to one of our informed sales advisors. 

Manchester Airport Group’s LED switch-over

Manchester Airport Terminal 2

As part of their wide ranging sustainability programme, Manchester Airport Group (MAG) have replaced costly, high maintenance, outdated incandescent and fluorescent lighting with Philips LED luminaires in Manchester airport’s Terminal 2 and in Olympic House, MAG’s Head Office.

Philips' PowerBalance LED luminaire

The newly refurbished Terminal 2 at Manchester Airport is now illuminated using a combination of Philips’ PowerBalance and GentleSpace LED luminaires. Using these two different luminaires, lighting designers were able to accommodate the variation in ceiling height within the two terminal halls. To achieve a consistent light output through the terminal halls, higher mounted applications required a higher light output than those replacing the ceiling recessed lighting. Philips’ GentleSpace luminaires deliver the required high lighting output while PowerBalance luminaires provide an efficient and cost-effective LED alternative to the outdated, ceiling-mounted, fluorescent lighting.

Philips GentleSpace LED luminaire

In total, 2498 luminaires were replaced and a further 1356 were deemed redundant and so were removed during the LED switch-over. The installed electrical load within Terminal 2 has now been reduced by 2,225,879 kWh and the terminal’s carbon emissions have been reduced by 1,206 kg. Due to the LED lamps extended life time, maintenance and re-lamping costs will also be reduced meaning MAG can anticipate significant savings across the board. Both Philips’ PowerBalance and GentleSpace are included on the Energy Technology List, enabling MAG to claim tax exemption through the government’s Enhanced Capital Allowances Scheme.

All luminaires have been fitted with DALI cabling and control gear using this MAG created a unique, easy to use, cost effective lighting management system set to meet their unique control requirements. An essential requirement of the lighting within Terminal 2 was digital dimming; this functionality can also be achieved using DALI technology. MAG integrated the lighting control system with their in-house flight movement system aligning light levels to coincide with passenger movement and numbers ensuring lighting is being not wasted in unused areas thus maximising energy savings. 

Olympic House

After seeing the success of the LED switch-over in Terminal 2, MAG decided to upgrade the lighting in their Head Office, Olympic House. Earlier this year, Olympic House’s five floors were given a make-over, during the refurbishment MAG took the opportunity to reduce their carbon footprint, cut energy emissions and still receive a reasonable return on their initial investment. Through using Philips LED lighting and control systems MAG have created a modern, energy efficient, working environment.

Philips LuxSpace Compact LED luminaire

LED lights and control systems were installed on the ground, 3^rd, 4^th, 5^th and 6^th floors of Olympic House during the renovation. In open plan office areas, general lighting is provided using PowerBalance LED modular recessed luminaires. PowerBalance luminaires have a consistent light output and offer stable colour performance, their long lamp life means cost of ownership is low making them a smart, cost-effective lighting choice. In circulation areas, PowerBalance luminaires are complemented by LuxSpace Compact and StyliD mini recessed LED down-lighters providing feature lighting.  

Philips StyliD LED luminaire

To further maximise energy savings, lighting is Olympic House is controlled using Philips’ Dynalite control system which utilises the DALI protocol based on an Ethernet backbone. The control system has been configured so that other areas of the building can be added into the control system at a later date; the control system will be regularly maintained by Philips through their Control After-Care Package. As well as adding new areas to the system, Dynalite head end software enables MAG to easily reconfigure the lighting should the layout of the workspaces change in the future.

In office areas daylight harvesting technology is used meaning the lighting is linked to photocells and dimmed according to the rhythm of the natural daylight ensuring the required lighting levels are maintained using the minimum amount of energy. In areas of variable occupancy, presence detection sensors are used to ensure lighting is only on when required. In addition to these innovations, Olympic House’s meeting rooms have pre-set scene controls, while the board room has a touch screen interface which offers a more extensive control of the luminaires.

Light provided by Philips has transformed both Olympic House and Terminal 2. Since the switch-over, MAG has received positive feedback from staff and customers alike. After seeing the effects of these renovations, MAG staff from areas which were not included in the switch-over, have now requested LED lighting within their departments!

For more information on any of the lighting or control systems within this project or any LED product visit our website http://theledspecialist.co.uk/ or call the office 0118 950 7125 to speak to an informed lighting specialist. 

Harsher penalties are introduced for those who knowingly contravene WEEE regulations

Following new guidelines created by the Sentencing Council (SC) of England and Wales, judges could soon impose harsher sentences and fines to both companies and individuals who are convicted of environmental crimes such as fly tipping and pollution.These new guidelines, which will come into effect on 1st July 2014, mean businesses now risk up to £3 million fines for incorrect, unsafe mercury lamp disposal.

This is the first time the SC has produced guidelines for these types of offences; their creation is due to magistrates' lack of familiarity with sentencing for these offences, a lack of standardised sentencing among magistrates and low fines which do not reflect the seriousness of the offences committed. The new guidelines are likely to lead to much larger fines for serious offenders.

A variety of offences related to the disposal of waste covered by the Environmental Protection Act 1990 and the Environmental Permitting Regulations 2010 are covered by these new guidelines. The new guidelines also apply to the highest offence category, hazardous chemicals. Waste fluorescent lamps are classified as hazardous and so all those collecting or transporting waste lamps must adhere to WEEE regulations. When these guidelines come into effect, the risk to any individual or company who knowingly fly tips or disposes of waste lamps inappropriately will be much higher!

As of 1st July, companies and individuals who knowingly break the law will face much stiffer penalties than those who break the law despite attempting to adhere to WEEE regulations. The largest recommended fine is a staggering £3 million, this will be imposed on large businesses who knowingly contravene the law; individuals caught doing so could face prison sentences of up to three years.

Speaking of the guidance, SC member and magistrate Katharine Rainsford said: "Illegal disposal of hazardous waste not only causes damage to the environment but puts peoples' health at risk as well. This guidance from the courts will help ensure consistent and appropriate sentences for offenders. These crimes are normally about making or saving money at the expense of the taxpayer. They also undermine law-abiding businesses in the waste management industry who are contributing to economic growth. The guideline aims to ensure that sentences hit offenders in their pocket."

It's not a fixture, it's not a lamp, it's Philips' OneSpace luminious ceiling

Philips lighting have once again shown astounding creativity with LED technology, their OneSpace luminaire literally fills the entire ceiling with homogenous white light. American author and professor of biochemistry, Issac Asimov predicted the creation of this luminaire in a 1964 New York Times article discussing the technology of the future, he wrote: "By 2014, electroluminescent panels will be in common use, ceilings and walls will glow softy...". 

OneSpace by Philips integrates LED lights with textile; this combination creates a white light ceiling surface and hides the light source completely. OneSpace luminaires create a smooth, clutter-free ceiling which emits a uniform, glare-free light.

Philips lighting representative, Antoon Martens said: "This innovation will redefine how light can be used in architecture and design. Light is now an architectural component - it is no longer an add on in a space. The ceiling is not often seen as a designer element - now, it is transformed by this minimalistic ultra-thin panel of light into a design statement."

Philips' OneSpace luminous ceiling plays a duel role as both the lighting and the ceiling itself, meaning no additional ceiling is required. This luminaire uses LEDs which are closely positioned in a mesh like arrangement; the LEDs are combined with textiles to create sound absorbing panels which emits Philips' signature homogenous light quality. The OneSpace luminous ceiling adheres to all UK building and safety requirements, making installation a breeze. 



Architects who were involved in validating the OneSpace luminous ceiling described its effect as being "peaceful", "serene", and "sky-like". The white light emitted from the ceiling recalls the feeling of natural daylight. It is especially suited for car show rooms, flagship retail stores and public spaces including airports, hotels and conference facilities. 

The OneSpace ceiling has dimming capabilities, may be used as a safety lighting, can be connected to the buildings lighting management systems enabling centralised on, off control and therefore saves energy. The OneSpace ceiling is available in customised sizes up to 10 x 3 metres, providing maximum freedom of design, creating a striking and calm space while also serving as functional lighting. 

For more information on this or any other LED product visit our website http://theledspecialist.co.uk/ or call the office to speak to one of our informed lighting specialists 0118 950 7125

Philips present the world's first clear LED lamp

Global lighting innovators Philips, have bought the traditional incandescent lamp into the 21st century by combining the aesthetic beauty of incandescent lamps with the latest LED technology. Philips' clear LED lamp has a unique innovative lens which emits beautiful light whilst retaining the classic shape of incandescent lamps. 

This latest development is the biggest change to incandescent lighting in the past 100 years. This 40 watt lamp contains the first LED capable of emitting light in all directions. Whilst maintaining the elegant shape and sparkling light of traditional incandescent lamps, Philips' clear LED lamp saves energy, has a lifetime of 25,000 hours, emits 470 lumens and even when dimmed maintains the same brightness levels as its 40 watt incandescent counterpart. 

Philips noted consumers' reluctance to switch-over to LEDs within the home as home-owners want to hold onto the traditional warm light and shape of incandescent lamps. Philips' clear LED lamp allows customers to hold onto the light they love whilst enjoying all the benefits of modern LED technology. The clear LED means the classic shaped lamp keeps its original beauty making it a seamless replacement for the standard 40 watt (A60 shape) lamp. This lamp is ideal for application in the living room and other areas where quality of lighting really matters. 

Rene van Schooten, CEO Light Sources & Electronics for Philips Lighting said: “With our L-prize LED bulb we showed that we could match the quality of incandescent light. With our clear LED bulb we’ve combined the aesthetic beauty and shape of the traditional incandescent with the benefits of LED. Using our innovations in LED the bulb is highly energy efficient, saving up to £8 per lamp per year.”

                               Features of Philips’ clear LED bulb:

• Innovative lens for sparkling filament like light effect
• Dimmable
• Shape: A60
• Lifetime: 25,000 hours
• Colour Temp: 2700K
• Lumens: 470
• Energy efficient and cost saving: 85% energy efficiency (6w input wattage: 78 lumen per watt ratio)
• Perfect light distribution (omnidirectional): >240D
• Ideal for application in homes, hospitality and retail

Philips Li-Fi: Smart lighting, smart shopping

Philips’ latest LED innovation; the Li-Fi system, is being piloted by a number of retailers. Li-Fi uses in-store lighting to transmit information to the camera on consumers’ smart phones. Customers who have downloaded the app will be alerted of nearby offers, receive recipes and can be directed to specific items on their shopping lists.

Li-Fi uses Visual Light Communications (VLC) to communicate with customers’ smart phones; it is a one way communication system meaning consumers’ identities are protected. The stores ceiling luminaires are placed in a positioning grid, communicating with the camera sensors in their smart phones. Each lighting fixture in the grid communicates by blinking at frequencies so high they are undetectable to the human eye. Through these fast pulses information is transmitted relevant to the customer’s location within the store.

In addition to the energy saving benefits of LED lighting, this latest invention means retailers do not have to invest in additional infrastructure to house, power and support location beacons for indoor positioning. The light fixtures themselves can communicate this by virtue of their presence all over the store.