How to evaluate

Initiated by the VELUX Group How to evaluate daylight the , diffuse skylight, and reflected from Daylight Daylight ground ground and surrounding elements. in in buildings is composed of a mix in buildings – direct direct provisions provisions indoors surroundings can be a major situations, the light reflected from the ground and reaching the building facade. In some dense building surroundings will influence the total amount of reflected light neighbouring that reflectedis from the ground: terrain, trees,vegetation, Reflected light diffuse is often the main source of useful daylight. bright overcast in the summer. In a cloudy climate, the 000 in the winter and as high as around 000lux 30 on a level produced by an mayovercast sky reach 10 and , resulting in soft, diffuse light. The Skylight shading and reflecting. is required, with careful management of allowance, diffusing, conditions. In a sunny climate, thoughtful architectural design sunlight by varies , time of day, location and sky of the may exceed lux. 000100The of direct constant movement. The illuminance produced on the surface Direct sunlight sunlight is is characterised buildings buildings etc. The surface of the is is is characterised characterised by sunlight scattered by the conributory by light by light (sunlight and skylight) by very high intensity and part of daylight

Initiated by the VELUX Group How to evaluate daylight availability in the interior. performance indicators to determine daylight It the is measure of light currently used by most It received on a surface. Illuminance the is measure of the amount of light Illuminance is typically typically is expressed in lux (lm/m² ).

Initiated by the VELUX Group How to evaluate daylight comfort comfort and in the interior. It the is measure of light used to evaluate visual It typically is expressed in cd/m². reflected or emitted from a surface. Luminance is is the measure of the amount of light

Initiated by the VELUX Group How to evaluate daylight Daylight software (e.g.software VELUX Daylight Visualizer). computer simulations with (shown Illuminance belove levels ) or predicted through the use of can can be measured with a measuring recognised and validated luxmeter devices simulations with and luminance mapping software (e.g. the use of high dynamic range (HDR) imaging techniques together with digital Luminance levels recognised can can be measured with a luminance and validated software (e.g. VELUX Daylight Visualizer). Photolux ) or or through through the use of computer meter (shown (shown belove ), through

Initiated by the VELUX Group How to evaluate daylight during during (CIBSE,2002). which case electric will most not likely be used strongly needed to perform visual A room tasks. will appear considered room. Rooms with an averageDF of or 2%more can be The higher the DF, the more daylight is available in the sky conditions unobstructed daylight available outside under overcast room (on a work plane) compared to the amount of that expresses the amount of daylight available inside a Daylight indicator Performance daylit factor (DF) daylit . when the average DF is 5% or more, in , but electric lighting may still be is a daylight adaylight is availability metric

Initiated by the VELUX Group How to evaluate daylight 1.9.4. Society of North America (IESNA, see 2013),section currently promoted in the Illuminating Engineering above the target illuminance, are values that are meaning 50%, 50% of the time daylight levels are A target illuminance of lux 300 and a threshold DA of met by daylight (Reinhart, 2001 time when the target illuminance at apoint in a space is that corresponds to the percentage of the occupied Daylight Autonomy Daylight autonomy autonomy (DA) adaylight is availability metric ).

Initiated by the VELUX Group How to evaluate daylight orientations and more. properties, room surfaces, conditions, sky locations, different scenarios such as window layout, pane Users Daylight Visualizer Simulation can can perform quick comparisons between tool

Initiated by the VELUX Group How to evaluate daylight orientations and more. properties, room surfaces, conditions, sky locations, different scenarios such as window layout, pane Users Daylight Visualizer Simulation can can perform quick comparisons between tool

Initiated by the VELUX Group How to evaluate daylight VELUX Daylight Daylight Visualizer rendering. . A picture from the house after construction. Daylight Simulation Visualizer tool

Initiated by the VELUX Group How to evaluate daylight architecture © SOLID Austria SOLIDarchitecture, Kindergarten Neufeld, it does with the double size of glazing in the facade. daylight performance in one of the group rooms, than provide a view out and a top light result in a better In this particular case, acombination of windows that mean Bigger ratio of glazing Daylight tool Simulation good good daylight daylight Visualizer distribution distribution in a does not automatically room. facade roof ( Ratio glass light: 1,8% light: / of floor glazing glazing area : 16,2 % : : 18 % 18 : ) facade roof ( Ratio glass light: 0 0 light: % / of floor glazing glazing area : 40 40 % : : 40 40 : % )

Initiated by the VELUX Group How to evaluate daylight Daylight Simulation Visualizer tool Design used better if re levels in certain which could be 2%By DF). contrast, it shows high light room facing east (e.g. 5%DF instead of located in the central part and the dining sufficient, such as the gymnastic room building where the light levels are not The factor (DF) performance design are evaluated using the daylight The daylight conditions in the initial Initial simulation simulation shows the areas of the design optimizations - distributed. , Solhuset Kindergarten, Denmark indicator. rooms rooms have sufficient daylight. model, ensuring that all the activity are much higher than in the previous part of the building and the dining room The openings of the window building. This new model also included light levels in the central parts of the evaluation, aiming to reach adequate based on the findings made in the first A Revised revised window revised window layout is proposed light light levels obtained in the central design linings. with with the initial design. improvement over the results obtained final design shows a significant The distribution of daylight inside the while keeping a generous and good solution in terms of ceiling construction, final design to promote a more rational linings opening has been optimized in the of windows and size of the window According Final daylight daylight simulation factor of the design to to the architect, the number rooms.

Initiated by the VELUX Group How to evaluate daylight and locations. It can do so weatherfor all conditions, from the ground and nearby structures. from the , and sky clouds and the reflections natural Artificial with sun Artificial lighting evaluation sky physical accurately conditions; those arising sky simulates / models external © Danube University © Artificial sky Krems

Initiated by the VELUX Group How to evaluate daylight © Danube© University Artificial sky Krems

Initiated by the VELUX Group Model under How to evaluate daylight with Artificial physical models artificial sky/sun evaluationsky/sun sky Daylight in in a model under artificial sky Daylight visualizer rendering Daylight in in actual house

Initiated by the VELUX Group Initiated by the VELUX Group