What is UGR? How to Become UGR Compliant | Unified Glare Rating

What is UGR?

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What is UGR?

UGR, which stands for Unified Glare Rating, is a numerical assessment of the glare emitted by lighting fixtures. Glare, especially in environments with numerous computer monitors, can have negative impacts on well-being and productivity within the workplace.

The UGR scale spans from 5 to 40, with lower values representing reduced glare levels. Its calculation involves a precise formula that divides the luminance of a luminaire by the visible light luminance originating from the room’s background.

International standards such as EN12464 delineate recommended maximum Unified Glare Ratings (UGRs) across different contexts, with a suggested UGR<19 for numerous office and classroom settings.

It is imperative to note that UGR is assessed for an entire lighting installation rather than individual light fittings. Nonetheless, the design attributes of a light fixture wield considerable influence over the resultant UGR of the overall installation within its designated application environment.

How is UGR Calculated?

UGR calculation is performed using commonly employed lighting design software like Relux, Dialux, and AGi32.

Input data essential for this calculation encompass photometric files of the intended fittings within the lighting scheme, room geometry specifications, surface reflectance values, and the layout details including the number and spacing of the fittings. Utilizing this information, the lighting design software can accurately compute the UGR value.

Factors Contributing to High UGR

  • Increased lumen package can lead to higher UGR due to greater luminous output.
  • Larger room sizes with more light sources in the field of view can elevate UGR levels.
  • Lower ceiling heights imply lower mounting heights, potentially correlating with higher UGR.
  • Luminaire distributions featuring high-angle brightness can contribute to elevated UGR values.
  • Lower surface reflectances within the space can also be associated with higher UGR.
  • The size of the luminaire aperture can influence UGR ratings.
  • Greater spacing between luminaires may result in higher UGR levels.
  • The relationship between the luminaire’s maximum candela angle and the observer’s line of sight can impact UGR values as well.

How to Reduce UGR of an Installation?

  • Evaluate the positioning of room occupants concerning light fittings. For instance, in a classroom layout, arrange lights to avoid direct line-of-sight with students as they face the teacher.
  • Deliberate on the selection of light fittings. If they are suspended, explore the possibility of lowering their suspension height.
  • Explore the inclusion of an uplight component. Directing light towards the ceiling reduces contrast between fittings and the background, thereby lowering UGR.
  • Opt for ceiling-mounted fittings with narrower beam angles to reduce perceived luminous intensity for viewers. To maintain uniformity, adjust wattage and increase the number of fittings if necessary.
  • Consider fixtures where the light source or emitting surface (e.g., diffuser) is recessed behind a bezel for reduced glare.

Bri-Tek Technologies UGR Promise

Here at Bri-Tek Technologies, we are known for our commitment to providing UGR compliant lighting solutions. With a strong emphasis on innovation and quality, Bri-Tek Technologies promises lighting products and systems that adhere to Unified Glare Rating (UGR) standards, ensuring optimal visual comfort and safety for users. Their dedication to UGR compliance reflects their broader mission to enhance overall lighting performance while prioritizing user well-being and productivity.

Get in touch with us today, and find out how we can help you become more UGR compliant.

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