Questions you may want to ask when considering which led to buy
All of the LED products supplied by Blazes come with a full TUV Certificate confirming safety and full compliance with all regulations.
A TUV Certificate has an individual serial number which is fully traceable back to the source of manufacture. This should not be confused with a CE certification which can easily be obtained from unregulated test laboratories which may not even have seen the products they are approving!!
All products supplied by Blazes have undergone these tests.
If not you can’t guarantee consistency of quality and traceability should a problem arise. All of the factories manufacturing products for Blazes meet the ISO standards.
All products supplied by Blazes are sourced from UK suppliers and any warranty issues are handled by Blazes, backed by the UK distributor. None of Blazes customers are asked to send faulty products to China for verification.
All products supplied by Blazes are. LED products use electrical solid state technology and if faults occur the consequences can be catastrophic and your insurers will be asking many questions concerning what due diligence you have exercised when sourcing these products.
The LED products supplied and installed by Blazes are sourced through one supplier for whom we are a national distributor. Bright-LED are both manufacturers and importers of LED products. Their attention to detail and knowledge of the LED industry means that each of their LED products is “best of breed”. For example the T8 tubes will be sourced from one manufacturer and the High Bay products will be sourced from another. This careful and considered selection process means that you can be sure that all LED products supplied by Blazes are the very best available and are covered by product liability insurance and warranties here in the UK.
General questions - Costs and LED Applications
LEDs are light emitting diodes. These are electronic components that produce light by conversion of electrical energy directly to light by the movement of electrons within the material of the diode. They are important because due to their efficiency and low energy, they are beginning to replace most conventional light sources.
A light engine is the LED equivalent of a conventional lamp. It normally consists of the LED chip mounted on a circuit board which has electrical and mechanical fixings. I.e. the light engine is ready to be fixed in the luminaire. Note that it need not have one chip; it may be an array of 9 or 16, sometimes with a phosphor coating.
LEDs are made of electronic components which need to be packaged together to offer long lasting efficient light sources to the end user. Apart from the LED chip itself which has sapphire and gallium in the semiconductor, the process of packaging with materials like ceramic, rare earth phosphors, silicone, solder and gold wire add to the overall cost. White LEDs require further tests for calibration and standardisation.
Although the initial cost of conventional light sources is less than LEDs, they do not take into account the operational and maintenance cost of the lighting system. LEDs, having a longer life, reduce maintenance and lamp replacement cost. This reduces cost of labour to replace lamps and the cost of new lamps at the end of lamp life cycle. LEDs, also consume less energy. Thus the overall cost of a LED system can thus be significantly lower than conventional lighting systems. Most applications with LEDs offer a payback period as low as 1 – 2 years.
Here are some aspects that need to be taken into consideration: when
- The luminaire spacing and layout
- Preventing a view of the light source and minimising glare
- Ventilation/cooling of LEDs
- Wiring access
- Access to LEDs in case of maintenance or replacement
- Location of driver, if not integrated in luminaire
- Switching / dimming or control type and location
- The lamp base / holder screw fixing position.
- The physical dimension of the LED lamp and how it fits into the existing housing.
- The electrical characteristics of LEDs compared to the existing system. (mains voltage, low voltage, control methods).
- The location and size of the light emitting surface in relation to the luminaire reflector and in comparison to the original light source.
- The light distribution, lumen output and other photometric properties like colour temperature in comparison to the original light source.
- The heat generated by the LED during operation and the maximum operating temperature.
It is important to compare the spectral power distribution of the light source (SPD), the Colour Rendering Index (CRI), Correlated Colour Temperature (CCT) and the Colour Quality Scale (CQS) of the light source relative to the nature of exhibits / displays to be lit. The illumination level on the exhibit and hours of operation also need to be considered. This is a specialist area and needs the advice of a consultant such as the curator.
In retail and display environments where the range of products change by the season, the colours can be changed to match the type of product on display. For example electronic goods may require a Cool white light while a Warmer tone may be required for fabrics. A fashion season which has red as a theme can utilize a colour of light with more red in its spectrum to enhance and bring out the vibrancy of the display.
LEDs offer the capability of changing from Warm white to Cool white through digital control of the LEDs. This can be used in indoor or partly outdoor environments where the illuminance level and colour temperature can be adjusted to match the outdoor conditions (sunny, clear sky day or overcast day) depending on the intended feel required in the space.
In Europe, every light fitting must have a CE label. This tells you that the seller claims that the fitting conforms to all the relevant European safety standards. The most important of these is EN 60598 which covers electrical, thermal and mechanical safety.
LEDs are low voltage devices. Hence they require a device / power supply unit / driver or integrated electronics that convert line voltage to low voltage to run the LEDs. Sometimes the driver has electronics that can interpret control signals to dim LEDs.
Dimming LEDs offer the following advantages:
- Saving energy, because less energy is used for reduced output levels.
- Extended life; the electronic components run cooler. This not only extends the life of LEDs but also increases the life of the phosphor coating that is used to produce white light.
- Helps designers create ambient lighting presets to create mood settings.
- Flexibility in usage of space. A brightly lit space for reading or an office space can turn into a presentation/conference area by dimming.
- Increases productivity by individual control to reduce eye strain and fatigue or to improve concentration.
50,000 hours would imply 5.7 years if the light is operated for 24 hours in a day, 7.6 years if the lights are on 18 hours per day and 11.4 years for 12 hours a day.
Unlike conventional light sources that reduce in output and eventually fail, LED products do not normally suddenly fail. Instead, the light output reduces over time.
The normal convention is to quote the life when the output has reduced by 30%. I.e. when there is 70% light output remaining. This is often quoted as the L70 life and is measured in hours.
Unlike discharge lamps, LEDs are semiconductors and their life span is not affected by the number of times they are turned on and off.
Typically, an LED will last four times longer than a CFL and 25 times longer than an incandescent source that puts out the same amount of light.
Sometimes simply comparing the lumen output of LEDs and conventional light sources may not be adequate. The amount of light falling on specific task area (the lux) gives a more realistic comparison. You should also consider the illumination on the walls. This helps identify applications where LEDs offer better solutions than other light sources.
In many cases when comparing the lumen output between LEDs and conventional light sources, LEDs may have lower lumen value However LEDs are directional light sources. All the lumens emitted from an LED are directed towards the task area; while conventional sources emit light in all directions which are then modulated in a given direction with optical systems like reflectors and lenses. The proportion of lumens that falls in the task area from an LED light source is greater than that of a conventional light source.
LEDs are more efficient than most other light sources, so they usually consume less energy for a given task or light output. Also, they do not contain hazardous materials such as toxic mercury. Moreover, LEDs have a longer lifespan and hence reduce the frequency of disposal of lamps.
LEDs are primarily made of electronic components consisting of PCBs, diodes, semiconductors etc. and so are treated the same way traditional electronics are treated. They are collected separately
Most LED tubes, although they have the same size, lamp base and possibly a lumen output close to that of linear fluorescent; do not have the same omni directional light distribution of linear fluorescents. Many luminaires, especially troffers with reflectors that offer batwing (wide-spread) light distribution with fluorescents; emit 20%-30% less light output with narrower beam spreads with LEDs. This needs to be taken into account when considering the overall 30-50% less power usage by LEDs with increased system efficiencies.
It is likely that the luminaire will need some rewiring and this should be done in conformance with the local electrical installation standards.
No. LEDs directly convert electrical energy to photons. It is a one step process of electroluminescence that does not require time to reach maximum output. Other sources such as fluorescents or HID work on discharge technology. This requires an arc to warm up and may take a few minutes to reach full output.