Purchasing advice LED panel selection guide

LED panels are a very popular and attractively priced option for illuminating rooms brightly and, above all, evenly. They are available in

• in many different sizes and dimensions
• in many different light colours
• with many dimming and control options
• in different qualities and efficiency classes

Before buying an LED panel, you should consider the following points

• What is the work and visual task in this room. How much light is needed.
• What options do you have for mounting the LED panels?
• Which light colour is best suited for your application
• Do you need particularly high colour rendering?
• Is there a need for control or dimming
• How many hours a day are the LED panels in operation?

Which light colour / colour temperature should be selected for LED panels and which light quality

The light colour and the colour rendering index (CRI) are important technical features. LED panels are available in various colour temperatures, typically in the range between 2700 - 3000K (warm white) and 6500K (cool white / daylight white).

Warm white light in the 2700-3000K range is particularly suitable for rooms and spaces in which a cosy atmosphere prevails. Example in:

• Foyers in hotels
• Employee break rooms
•  Doctors' waiting rooms
• Wellness and spas, bars or
• Yoga rooms or physiotherapy

warm white light is also used in most cases.

Neutralweiße Licht liegt zwischen ca. 4000K und 4500 Kelvin. Es ist ein weit verbreitetes Arbeitslicht. Neutralweißes Licht bei LED-Panels wird gerne eingesetzt in:

• Offices
• Corridors and reception halls
• Medical practices, especially general medicine
• Schools
• Group rooms in daycare centres
• Meeting rooms
• Restaurant kitchens
• Hairdressing salon
• Study

Daylight white or cool white light is often used in rooms where concentrated work is carried out or colour differentiation is important

• Doctors' treatment rooms, especially in dental practices
• Laboratories
• Quality controls
• Detailed precision work
• Printing, working with colours and photography
• Cosmetics shops and beauty parlours
• Nail salons
• Museums and galleries

Cool white light is in the range from around 5000K to 6500 Kelvin and is often referred to as daylight white.

Dual white or CCT LED panels (Tunable White) have a wide light range with light colours of warm white, neutral white and cool white. These are mixed with each other or switched through in defined steps. This allows you to practically adapt the light to the respective activity. The CCT panels or Tunable White LED panels usually use a remote control and can also be dimmed.

In the premium segment, LED panels are controlled via DALI DT8 LS TUNABLE WHITE.

We generally recommend using LED panels with a colour rendering index of CRI> 80. This should be a minimum requirement. For standard office work, a CRI>80 colour rendering is completely sufficient. The LED panels from Cologne-LED.de have a CRI of 84 and higher.
In some industries, however, a significantly higher colour rendering is required in order to display colours vividly. These industries are primarily

• Fresh goods such as fruit and vegetables in grocery stores
• Hairdressers to show the result of hair colouring as accurately as possible
• Body shops and car dealerships that do not want to see any colour differences during painting work.
• Retail trade with high-quality products
• Galleries. Museums or exhibitions

More about colour temperature

What colour rendering CRI value / RA value do I need for my applications?

We generally recommend using LED panels with a colour rendering index of CRI> 80. This should be a minimum requirement. For standard office work, a CRI>80 colour rendering is completely sufficient. The LED panels from Cologne-LED.de have a CRI of 84 and higher.
In some industries, however, a significantly higher colour rendering is required in order to display colours vividly. These industries are primarily

• Fresh goods such as fruit and vegetables in grocery stores
• Hairdressers to show the result of hair colouring as accurately as possible
• Body shops and car dealerships that do not want to see any colour differences during painting work.
• Retail trade with high-quality products
• Galleries. Museums or exhibitions

Einen CRI-Wert von 99 oder 100

A very high CRI value of 99 or 100 is usually found in high-end car dealerships or museums.
The CRI value or RA value indicates the colour fastness of an artificial light source compared to daylight using 14 reference colours. 100 is the highest value. Low CRI values usually show colours as pale or distorted.

In addition to the CRI value, there are other criteria for representing the light quality of a luminaire, such as the GAI value, which reflects the vibrancy of an illuminated object, and the CQS value, which takes various factors into account as a colour quality score.

We offer LED panels with a CRI94 and higher. Simply enquire with us.

LED panels have a high luminous efficacy with low power consumption. Despite large-area illumination, glare effects can occur. Especially with low ceilings and a high light requirement in LUX.  The UGR value stands for Unified Glare Rating and indicates the glare of a luminaire. The lower the value, the lower the glare.
Glare from light should be avoided

• In offices at computer and monitor workstations
• In logistics, for example in high-bay warehouses for forklift traffic to prevent accidents
• In school classes and daycare centre group rooms
• For precision work, for example in quality assurance or precision mechanics 
• In retail with low ceilings for a pleasant shopping experience
• In sports halls for ball sports, when looking upwards
• For precision work, for example in quality assurance or precision

Low UGR glare value = high visual comfort

A value of UGR<19 is prescribed in offices and classrooms. UGR19 LED panels with low glare and diffuse light emission are available for this purpose.
A UGR value <21 should be present in logistics warehouses. The luminaires are usually hung a little higher there.

In precision mechanics, when working with paints or glossy surfaces, lower UGR values of <16 are sometimes used.
A low UGR value ensures a pleasant working environment and longer periods of concentrated work for employees. Low glare is easy on the eyes and reduces fatigue.

More about the UGR value: glare from a luminaire

Flicker, flickering, high flicker component in the

A frequently underestimated factor for unfocussed work or headaches after long days in the office is a high flicker component in the light. This leads to sleep disorders in some employees. The reason is 50Hz flicker in low-quality power supply units, which is particularly common in very cheap LED panels.

How can flickering be detected in light?

Hold the video camera of your smartphone against the light. If fast stripes move horizontally from top to bottom, then the flicker component in the light is too high. The screen should remain absolutely still.
If the flicker percentage is below 5%, luminaires are considered flicker-free.

LED panels with yellowed or brown surfaces and light

Why do LED panels simply yellow and turn brown after a certain time?
The yellowing or browning of LED panels is due to the plastics used in the light guide plates. If LED panels fade or turn brown, this is usually due to the quality of the light guide plates. Visually, this is an absolute nuisance.
LED panels with a tan colour usually use a plastic made of polystyrene (PS). This plastic has relatively poor UV stability, but is very inexpensive. The light transmission is also somewhat lower compared to other plastics.

Higher quality LED panels are usually made of PMMA / acrylic glass. PMMA has better light transmission than polystyrene and therefore better efficiency.

PMMA plastic as a light guide plate is very UV-stable and does not brown out during the service life of the LED panel. PC (polycarbonate) is also very light-stable and translucent, but is somewhat more expensive.

Energy efficiency

Energy efficiency is a decisive factor for LED panels. Depending on the surface, an efficiency of 120 to 140 lumens per watt is currently standard. In some cases, this goes up to 200 lumens per watt. These LED panels are then somewhat more expensive, but pay for themselves relatively quickly, especially with long daily running times. LED panels 62x62cm then have an output of 18-25 watts.

LED panels with a high CRI value of >90 usually achieve an efficiency value of around 100 lumens per watt, as these LED panels have to reproduce more colours and display a larger colour space.
LED panels with 80 lumens / watt, on the other hand, are outdated and should no longer be purchased. Exceptions are CCT panels, which have a slightly lower efficiency than single-colour LED panels due to the colour mixing.

Dimming and control for LED panels

Dimming and controlling LED panels is a chapter in itself. There are many different types of dimming. When dimming LED panels, you should be guided by the following criteria, depending on your control requirements

• Does dimming make sense in this area? Compare the additional costs with the expected savings
• How many LED panels should be dimmed at the same time?
• What are the existing structural conditions and the electrical installations?
• Is it easy to realise  dimming? 

Various suitable dimming types for LEDs

• DALI dimming:

DALI 2 / DALI 1 is usually used for dimming in new buildings nowadays. DALI luminaires can be easily integrated into the building technology or home automation system (SMART Home). Luminaires can be controlled individually in the DALI network, report error states independently and can also be combined very well with other sensors such as daylight sensors.

Dimming to zero (DimtoZero / Dim2zero ) is also possible. The Dali luminaire switches off automatically when dimming to 0.

However, an additional 2-wire data bus line or control line is required to control DALI luminaires. This makes it more difficult to implement in existing buildings with 3-core cabling.

DALI luminaires are somewhat more expensive than standard models but can achieve high electricity savings and therefore usually amortise quickly.

Ask Cologne-led.de for suitable DALI luminaires.

• Wireless DALI

• Nowadays, DALI luminaires can also be controlled wirelessly. Especially when it is too costly and uneconomical to lay new cable harnesses.

The wireless DALI control system also offers options for creating individual luminaire groups and switching states via APPS. These can also be switched and dimmed directly via Enocean wireless push-buttons.

• Trailing edge /  edge dimming / TRIAC

Dimming type suitable for smaller installations on LED luminaires. As dimming via the power line, it comes very close to the classic wall dimmer. However, the LED dimmer and the power supply units of the luminaire must be compatible. The number of luminaires to be dimmed also depends heavily on the power of the dimmer.

We prefer phase-cut dimming. There are many inferior power supply units on the market, which often leads to poor dimming results. It is also not possible to dim down as far with phase dimming as with DALI dimming

Ask us at Cologne-LED.de. We will help you choose the right dimmer and the right luminaires.

• PUSH Dimming

Dali control gear usually also supports PUSH dimming. This means that this can be realised using a wall switch. A total of three cables are required. One switched conductor and one continuous conductor must be available. Push dimming is more suitable for dimming a single luminaire.

• 1-10 Volt Dimming

1-10 volt dimming is analogue and can be dimmed between 10% and 100% via a 2-wire control line. As with DALI or PUSH dimming, this is done on the DC side. However, dimming to zero (0) is not possible with 1-10V dimming) Switching on and off requires a separate switch

• 0-10 Volt Dimming

The 0-10 volt dimming is similar to the 1-10 volt dimming. However, it is digital and the luminaire switches off completely when 0 is reached. It is also possible to dim down significantly lower with 0-10V.

• Casambi / ZigBee

  Casambi and Zigbee are wireless data transmission protocols in the field of building automation and smart homes that represent an alternative to WLAN. Both are energy-saving and work in mesh mode. This means that they are both transmitters and receivers, thus increasing the range.

Zigbee always requires a central radio unit. Casambi works via Bluetooth and does not require a central unit and is compatible with many dimming protocols. However, Casambi is only installed in the lighting sector and is not compatible with other actuators in the building sector.

In addition to the existing building, the number of luminaires installed and the additional energy savings, for example through daylight incidence, are ultimately decisive factors to consider. We at Cologne-led.de will be happy to support you in selecting the right dimming option for your project.

Reliability and quality requirements for LED Panels

Compared to private use, lighting in a commercial environment and use for many hours a day is subject to significantly higher requirements. This should be taken into account when planning and selecting an LED panel.

• Long guarantee periods from the manufacturer:
  Lights for commercial use should have the longest possible guarantee period from the manufacturer. Ideally at least 3-5 years. Then you also know that their products are designed accordingly.

Mounting options for LED panels

LED panels as insert lights

Led panels are often installed in suspended grid ceilings in commercial areas such as open-plan offices or retail outlets. Installation is quick and usually does not require many accessories.

The panel is connected to the LED driver and the luminaire is then ready for operation.

For grid ceilings, LED panels 62x62cm and LED panels 60x60cm are more common in the international sector.

Installing LED panels for ceiling surface-mounting with mounting frame

The LED panels are surface-mounted on existing concrete ceilings. This means with a ceiling mounting frame on the ceiling.

The LED panel and the power supply unit / LED driver are placed in the frame and form a self-contained unit.

LED panels for suspending from the ceiling as pendant luminaires

With very high ceilings, it makes sense to suspend the LED panels as pendant luminaires with cables. This is especially useful to bring more light onto the desk and the area to be illuminated, for example

They are then suspended using 4 wire ropes or alternatively 2-Y ropes.

Using LED panels as recessed luminaires

In rooms with plasterboard ceilings, it is also possible to install the LED panels with spring clips or in recessed ceiling frames. The advantage here is the visual appearance, as the LED panel is mounted almost flush with the ceiling as a recessed panel and barely protrudes.

The LED drivers are simply placed on the back of the LED panels and are therefore concealed. The disadvantage of this design is that large cut-outs are cut into the ceiling in order to install the LED panels, which can sometimes come into contact with wooden struts or beams due to structural conditions.

Common sizes of LED panels

Finding the right size of LED panel is not that difficult. We at cologne-led.de will be happy to help you plan your space depending on the conditions on site.

Here we show a few common sizes of LED panels that we sell a lot of and can offer in our range. These are standard sizes and can be offered in various light colours and dimming types.

LED panels 62x62 cm and LED panel 60x60 cm

These formats are specially designed for recessed luminaires in grid ceilings. The 620x620 dimension is more common in German-speaking countries (Odenwald ceilings). The 600x600 mm size is the standard in the marked international area (Armstrong ceilings). In conjunction with a surface-mounted ceiling frame, the LED panels can be used to create a large LED ceiling light relatively easily.

LED panels 120x30 cm 1200 x300 mm

LED panels 120x30 are very popular, especially as office lighting LINK. The 120x30 lights are very suitable for a large desk. The matching models provide the required brightness at the workplace. The 120x30 cm LED panels replace the 2 x36 watt louvre luminaires and require less than half the power.

In the majority of cases, these are installed as 120x30cm surface-mounted luminaires and the power supply unit is stowed in a ceiling mounting frame.

LED Panel 150x30 cm / 1500 x 300

The 150x30cm LED panels in long format are now in high demand. Especially in conjunction with a surface-mounted frame or spring clips for ceiling installation, the 40 watt models replace conventional 2x 58 watt fluorescent tubes.

The 1500 x300 UGR19 LED panels are also popular as office luminaires. Some of the 1500x300 luminaires are also suspended in the frame and converted into pendant luminaires above the workstation.

As 150x30 cm LED surface-mounted luminaires, we can offer these models in many different dimming options, for example as 150x30 DALI luminaires, with trailing edge dimming or with push dimming.

LED-Panel-1200x600-mm

The 120x60cm LED panels are suitable for illuminating large areas or as a kind of daylight window. Large format and lots of light. The 120x60 LED panels are usually purchased in conjunction with a dimming option.

LED Panel 300 x 300mm

Small LED panels in 30x30cm at a favourable price and still emit light. Ideal LED panels for corridors or small rooms such as small storage rooms or equipment rooms or anterooms of toilets. The 30x30cm LED panels are also used in corridors. With 15-20 0Watt output, they also offer a lot of power. They are often operated with only 10 watts.

Due to their small dimensions, the 30x30cm LED panels are more suitable for ceiling installation with a mounting frame than other formats. This is because the cut-outs do not have to be cut quite as large.

Customised LED panels

It is generally possible to have LED panels made to measure or to build customised LED panels. However, the prices of customised products are 10 times higher than the standard dimensions. We usually advise you to orientate yourself on the standard dimensions first and then switch to a special format if necessary.

Summary of advantages and LED panel

• LED panels offer a lot of light at affordable prices. They can illuminate entire rooms at low cost.
• They are available in many different light colours
• They can be flexibly attached, installed and mounted. There are many accessories for this
• The light emission is uniform and extensive. They create a beautiful light image
• Standard sizes allow the light panels to be replaced with other models even years later.
• Dimmers and controllers allow colours to be adjusted and varied on certain models.
• On the other hand, LED panels are more functional and angular in appearance
• LED panels are not suitable for fans of discreet or indirect light

In conclusion, it can be said that LED panels can be used in a variety of ways. However, their use should also be well planned. We at Cologne-led.de have been successfully realising projects with LED panels for many years. Let us advise you and simply give us a call on : +49221-29821660 We prefer to advise you personally.

Selection guide and technical advice from Cologne-led.de

We at Cologne-led.de will be happy to advise you on choosing the right office lighting and office lamps. Give us a call on +49221-29821660 or send us an e-mail.