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Glossary

A small collection of the most important words from the world of light.

  • Absorption

    The portion of radiation that hits a surface and is absorbed (trapped in the material). Given in percentage. The sum of absorption, transmission, and reflection is always 100%.

  • Candela

    Candela is the SI unit for brightness. It indicates how much light intensity a light source emits in a certain direction.

  • Daylight utilisation (dagsljusanvändning)

    Daylight utilization is about how well the curtain allows daylight to enter the room, which can reduce the need for artificial lighting and improve the overall light environment. It is assessed by measuring how much daylight is let through and how it is distributed in the room

  • Glare control (bländningskontroll)

    Glare control is about reducing glare from direct sunlight or strong light that can cause discomfort or difficulties in seeing clearly. Generally, it can be said that a dark colour works better than a light colour in the same construction.

  • g-total

    Total solar energy transmission through windows and solar protection together.

  • g-value

    The g-value indicates the total solar energy transmission through the window and the fabric. It's given as a value between 0-1 or alternatively in percentage. The higher the value, the more energy is transmitted.

    The g-value for a fabric is always given in combination with a window.

  • Shortwave radiation

    Shortwave radiation is electromagnetic radiation with wavelengths up to approximately 3000nm.

    Solar radiation consists of shortwave radiation.

  • Light flow

    See Lumen.

  • Brightness

    See Candela

  • Lumen

    SI unit for luminous flux (light energy per unit time). Abbreviated as lm.

  • Luminance

    Luminance (candela) per square metre. Measured in cd/m2.

  • Lux

    SI unit for illuminance, lighting (luminous flux per illuminated surface area). Abbreviated lx or lm/m2.

  • Longwave radiation

    Longwave radiation is electromagnetic radiation with wavelengths over 5000 nm. Also called thermal radiation.

  • Night Privacy

    Night privacy refers to the curtain's ability to prevent visibility from the outside when it is dark outside and the light is on indoors.  

  • Openness factor (Öppningsfaktor)

    The openness factor indicates how much of the fabric's surface is open to direct light or sunlight. It is expressed either as a percentage or as a number between 0 and 1, where 1 means completely open and 0 completely closed.

  • Operative temperature

    Perceived temperature. Approximately the average between air temperature and radiation temperature. 

  • Reflection

    The part of the radiation that hits a surface and is reflected back. Given in percent.

    The sum of absorption, transmission, and reflection is always 100%.

  • SF - Solar factor

    See g-value

  • Shading coefficient

    A way to specify the g-value for only a sunshade. It is obtained by dividing g-total by the g-value for the window, which gives g-sunshade (the value can only be used in the specific case)

  • Solar protection glass

    Dark glass that screens off parts of the solar radiation. Ambition to eliminate UV and IR, however, it is not possible without also screening off parts of the visible light.

  • Solar radiation

    Shortwave electromagnetic radiation consisting of UV, visible light (daylight), and IR (thermal radiation). Wavelengths within the range of 320-2500nm reach the Earth's surface.

  • ST - Solar energy transmission

    Watch Tsol

  • Visible light

    Part of solar radiation with wavelengths in the range of 380-780 nm. Also called daylight.

  • Thermal comfort

    When a person experiences neither discomfort from cold nor heat, based on thermal balance between the body and the environment. It depends on factors such as air temperature, radiation temperature, humidity, air movements, clothing, and activity level.

  • Transmission

    The part of the radiation that hits a surface and is transmitted (passes through). Specified as a percentage.

    The sum of absorption, transmission, and reflection is always 100%.

  • Tsol

    Proportion of the sun's radiant energy that passes through glass and solar protection into the room. Indicated with a value between 0-1 or in percentage of the total solar radiation.

  • TST – Total solar energy transmission

    See g-value

  • Tvis

    Percentage of visible light (380-780nm) that passes through glass and sun protection into the room. Indicated with a value between 0-1 or in percentage.

  • T-value

    Watch Tsol

  • U-value

    Heat transfer coefficient, i.e., describes the material's insulation properties, is given in W/m2 K. The lower the U-value, the better the insulation.

  • Visual comfort

    Visual comfort includes the concepts:

    o Glare control (Bländskydd)

    o Visual contact with the outside (Visuell kontakt med omgivningen)

    o Daylight utilization (Dagsljusanvändning)

    o Night privacy (Insynsskydd nattetid)

    Measured and classified according to the standard ISO 14500/14501.

    The classifications range from 0 (Very little effect) to 4 (Very good effect).

  • Visual contact with the outside

    Visual contact with the outside is about how well the textile allows visibility out through the window when it is drawn. A high value means that the contours of the surrounding environment are perceived as clear.

    Generally, a dark colour works better than a light colour in the same construction.

  • Radiant heat

    Thermal radiation is electromagnetic radiation with wavelengths over 5000 nm. Also called long-wave radiation.

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Designing daylight

How daylight works

Daylight changes throughout the day and the year – in intensity, direction, and colour tone. Here we go through how natural light works and how it affects the room, so that you can make better decisions regarding textiles, ingress, and visual comfort.

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Designing sounds

Advantages of textiles

What can you create with daylight? Here we show you how you can use daylight – not just block or let it through – to make light, visibility, and temperature your design tools.

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Designing sounds

Find the right textile for your project

All Svensson's hanging fabrics are classified according to how they affect daylight and are designed for environments where both design and function are a must. Find the right fabric for your project.