The LED vs Heat

Heat is a real enemy to the LED whether it is a replacement GU10 or a full luminaire so it is a constant battle to achieve a good design to reduce heat whilst achieving a high lumen output.

How often do you see GU10s looking very sorry for themselves?  Looking blue? Looking a bit jaded?  And this can happen after just a few hundreds of hours.

There are a couple of reasons; first, the design/quality of the lamp is simply very poor and it has failed after a short period or second, the lamp has overheated causing premature failure.

It is less likely these days for the lamp to be of poor design as manufacturing techniques have improved and component prices have come down.  You will notice most GU10 lamps have some sort of heatsink – or fins – around the LED and the miniature power supply is built into the end.  In free air this is almost certainly adequate – ensure good circulation and the heat is taken away from the components.  However, the majority of these lamps get used in the popular downlighter which is very effective at preventing good air flow past the fins.  Not surprising, really, as they were designed for halogen lamps with temperatures up to 700deg C with no need for cooling.

These are usually installed in ceilings with next to no airflow, trapped between the ceiling and the floor above and hidden under layers of insulation.  These areas get hotter and hotter, particularly in summer, and can quickly exceed the safe ambient temperature required around the lamp, typically 35degC. Be aware that whilst the ambient air temperature you can measure may be 30deg C, (apparently “safe”) the important ambient around the lamp itself could easily be 30 or 40 degrees higher, well in excess of safe operating limits for the components.  It will be far worse when used in the fire hood often required to meet fire regs.

The solution? Don’t install replacement lamps in luminaires designed for traditional light sources as they can’t keep ventilate but if you do, make sure there is adequate air flow to keep them cool.

Ideally use a complete luminaire designed specifically for LEDs.  These will be designed with LED technology in mind and will achieve much higher efficacies than replacement lamps (>100lm/W compared with 50 or 60lm/W)

Replacement LED 2D lamps

Everyone, it seems, is offering an LED 2D lamp.  They’re great – plug straight into the existing luminaire socket – fit and forget!  They even come complete with sensor options and emergency packs.

But, have you ever stopped to think about the spec. and how they’re used? No? Well here are some things you may wish to consider.

Firstly fitting them – it’s not quite as straight forward as simply removing the CFL type and plug in the new LED version.  More than likely the luminaire will have a high frequency ballast which you need to disconnect and bypass.  Even with a magnetic one, to achieve maximum energy saving, you need to bypass the ballast.  In both cases rewiring of the fitting is needed.

Then there is the emergency pack.  Fluorescent packs do not work with LED lamps so you will need to buy the LED emergency pack and work out how to install it securely adding to the time, and therefore, the cost of replacement.

Then there is the spec.  Most LED replacement lamps are quoted at 12 watts and around 1000lm.  Indeed a huge saving over the fluorescent type but actually not quite enough light. The cool white ones are 1000 lumens but the chances are you’re replacing a warm/neutral white lamp.  You’re probably only getting 800 lumens from these – well short of what is required.

The Earlsmann solution is to replace the complete gear tray – simpler to install – just the Live, Neutral and Earth to connect and the extra permanent Live for the emergency version.  They are rated at 15 watts so use a bit more power but then they give you 1200 lumens which provides a light level far nearer the original fluorescent. They don’t cost any more than the replacement lamp solution and are quicker to fit.

Of course it may not be suitable for every luminaire so you’ll need to ask us.

Earlsmann at Ecobuild 2014 with the ILP

Ecobuild wasn’t an exhibition that had been on our list of priorities until we had a call from the Institution of Lighting Professionals (ILP) inviting us to join them in their “Lightscene” zone.

We agreed, and were really pleased with the result.  Simon did a 15 minute talk on the Wednesday, “ Lux, Lumens and Watts”, inspired by the ILP “Guide to the Specification of LED Lighting Products 2012” to help people make more informed choices about LED lighting.  After all, LED lighting is a significant investment so it’s important to avoid the many pitfalls. (Also read our other blog articles).

We also took the opportunity to show some of our new products and gauge reaction:-

The Lincoln LED streetlight is available from under £150 and will easily replace up to 90W SOX luminaires.  At the price, it may be a much better option for S class areas than simply replacing the lamp.  This was very well received and several requests for further information were made from as far afield as the UK, Belgium, Spain and Kenya.

The Brighton Bay / Dover flood lights have interchangeable reflectors making it possible to change the beam angle to suit specific applications and for change of use of areas within a building.  LED lighting is a major investment so “future proofing” was considered a good idea.

Replaceable LED geartrays for 2D CFL bulkheads are a good alternative to the readily available LED replacement lamp as the driver is separate and better cooled, allowing the light output to better match the traditional lamp.  The standard LED replacement lamp doesn’t quite have the light output to adequately replace CLFs.  What’s more, replacing the complete gear tray is quicker and easier to install than rewiring for the lamp.

We met with many professionals and lighting specifiers so hope to see an increase in business.  The coming months will tell.

ECOBUILD 2014

Earlsmann are exhibiting at ECOBUILD on stand S548 and will be showing several of their new products.

First is the new LINCOLN LED street light which can be used in S class applications, car parks, walkways or public areas.  It has a gull wing beam pattern and has an efficacy up to 120lm/Watt.  Critically, this is the first street light available at under £150 and is made in the UK.

Next is the new corridor light.  This is a stylish bulkhead and is fitted with twin LEDs pointing along the corridor providing maximum uniformity and avoids the usual light-dark-light-dark that are normally associated with these areas.

Third are the new BRIGHTON S high/low bay and DOVER flood.  As your requirements change it may be useful to be able to  change the beam angle on your lighting to suit different mounting heights or a different use for a given area so these come with interchangeable reflectors to allow for this change of use and future proof your investment in LED lighting.

And fourth is the 2D replacement gear tray.  This is an alternative to a simple replacement lamp and is far easier to install.  MOQ of 50 pcs and we’ll need to see a fitting to make sure it fits.

LED lighting has come down in price but is still a significant investment so if you’re interested in learning a bit about how to correctly specify lighting and avoid some costly pitfalls, Simon Thornton will be giving a  presentation at the ILP Lightscene theatre on Wednesday 5^th at midday.  Why not come along?

LED Lighting and the 5 Year Guarantee

Nowadays it is a given that LED luminaires come with a 5 year guarantee.  But what does that mean and do you know if it can be honoured?  It is very easy to offer a 5 year guarantee; everyone is doing it!

If you’re buying your new light from a reputable supplier of branded products I’m sure there won’t be a problem but, with so many smaller businesses offering Far Eastern products at low prices it may pay to check what is covered.

Some suppliers are even offering guarantees up to 7 years (and even 10), and some include batteries on emergency fittings.  These guarantees should be treated with caution and the small print read thoroughly.   The chances are there will be strict limitations on service life and batteries almost certainly won’t last more than 4 years due to their charging duty cycle

LED lights should be considered as the piece of high tech electronic equipment they really are. Would you expect a television set to run 7 years (over 60,000hrs) without turning it off?

To Do

First, the product, check the specification of the light to make sure it really is fit for purpose, particularly with regards to ambient temperature, which can easily be overlooked.  Sometimes the fitting will only have a low ambient operating temperature, 35 degrees, say.  If your ambient is higher, perhaps 40degrees, this will void the warranty.

Is the guarantee for the luminaire only?

Does it include installation?
Is it a return to supplier guarantee?
Is it for the LED only or does it include the driver (power supply)?

LEDs, in the correct conditions, may well last 50k hours (6 years at 24/7 usage) but will the power supply?  The industry average for power supply failure is 7/1000 supplies.  This suggests that several of your fittings may be guaranteed to fail.  Has the supplier/you taken this into account?

Then, check the supplier.  Will they be around in the coming years to support the guarantee? It’s all very well having a 5 year guarantee but if the installer/lighting supplier has closed down, who is going to honour it?

If you'd like to discuss your options with Earlsmann, please get in touch

Lux, Lumens and Watts

There is a lot of confusion regarding Lux, Lumens and Watts which is worth clarifying so that the best luminaire for a given use can be correctly specified.

Asking the right questions
I am often asked if we can supply a luminaire in Watts.  Do you have a 50 Watt flood light?  Do you have a 100 Watt low bay light?  The answer is “Yes” but the question could be put better.

I need 150 lux in my aisle, do you have a light that can do that?  Or - I need 700 lux at working height in my workshop, can I do that?

Lux (lx)
The wattage of the luminaire, or the lumen output, aren’t important to answer the lux level required but are used to indicate how efficient the luminaire is.  Usually the minimum recommended lux level needed (illuminance at the required surface) is specified in health and safety guidelines, by CIBSE or a regulatory body.
For example, the HSE suggests a minimum average illuminance of 50 lux in loading bays. This is to provide adequate light to safely see other users and provide a comfortable light level to do the required task without causing eye strain.

The luminaire light output required to achieve this will depend on several factors – lux level required, mounting height, area to be illuminated and spacing of the luminaires.  Once this information has been established it is possible to work out the light output required from the luminaire to achieve the desired lux level.

Lumens (lm) is the light output from a given luminaire and
Watts is the power required to achieve it.

Once the lumen output has been established is the time to start considering the power (wattage) required and selecting the most suitable luminaire.

Efficacy (lm/W)
Lumens and Watts determine how efficient a luminaire is and is quoted in lumens/Watt.
A good luminaire nowadays will be at least 80lm/W.  The more efficient a luminaire the fewer will be required and the less power used.  Make sure the efficiency quoted refers to the complete luminaire not just the LED.  An inefficient power supply can lead to an inefficient luminaire.

Example
We recently supplied some Brighton High Bay lights to illuminate a production area to 700lx.  It was determined that we could achieve this using our 120 watt luminaire with a system efficacy of 90 lm/W.  We required 42 fittings.  If the efficacy of the luminaire had only been 60lm/W we would have needed to use either 42 x 180 watt luminaires or increased the number of fittings to 60.  Either the cost of the fitting increases significantly or the installation costs would increase.  Another important thing to note is that 50% more power would be required.

If you would like to discuss further please contact us at Earlsmann.

Earlsmann LED lighting updates

We're into the new year and have been busy with a number of updates. 

Within the Lighting Group we have updated all out data sheets for all our interior and exterior LED lighting products to reflect developments with LED lighting components.  A number of new Ledil reflectors have become available with efficiency over 93% allowing greater efficacy of our luminaires. These are used on our Brighton High and Low bay lights, Stafford and Dover flood lights.

The Dover is a completely new product developed in the last few weeks in response to requests for a waterproof bay light.  Already these are being used by Redbridge Council on their Liston Road estate to illuminate  the ground from the apartment tops and at Heathrow to illuminate some of the undercroft.

Ledil have also introduced a new lens - Stella.  This is also 93% efficient and lead to the new Telford 2 LED street light which is also now specified by Redbridge council for their car parks and walkways.