Light and Energy Lecture 7 PDF

5/31/2024 Light and Energy LECTURE 7 Lecture 7 Part III – DAYLIGHT 1. Daylighting General 2. Daylighting from above 3. Daylighting re-directing 4. Daylighting and Glazing 1 ...

5/31/2024 Light and Energy LECTURE 7 Lecture 7 Part III – DAYLIGHT 1. Daylighting General 2. Daylighting from above 3. Daylighting re-directing 4. Daylighting and Glazing 1  5/31/2024 2. Daylighting: Light from Above ▪ Daylight and Artificial Light- grid Ceilings Used in: ❑ Museums, Lobbies, wellness areas. ❑ Illuminating the space evenly and without glare Daylight and Artificial Light Grid Ceilings ▪ Light grid ceiling: available with daylight and/or artificial light ▪ Construction: aluminum profiles ▪ Materials: translucent or Printed film, single acrylic glass panels ▪ Light transmittance: between 30 and 50% 2  5/31/2024 Glazed Roofs ATRIUM ▪ Quantity of light decrease with the increasing distance from the glazing roof. ▪ Increasing illuminance (cloudless sky, amount of sunlight) increases the thermal load. ▪ Shading systems reduce the light incidence on the lower floors. ▪ Facades should be painted in bright colors to reflect light into the interior. ▪ Atrium support natural ventilation of the building. Atrium – Membrane Roof Structures ▪ Three layers of light-translucent flour-polymer film ▪ Inflated to two superposed pillows. ▪ Extremely thin film-layers, printed with grid pattern, reflect sun rays. ▪ At the middle film, the grid pattern is arranged offset, so that a largely closed surface is formed. ▪ Changing the air pressure in one of the two chambers, the middle sheet can be displaced and light transmittance can be changed according demands. ▪ Additional shading system is not required. 3  5/31/2024 Glass Roof Shapes ▪ Glass roofs provide three times higher illuminance as side lighting. ▪ Provide Uniform illumination. ▪ Size depends on use of the room and the desired illumination. ▪ Daylight, transparency, sun protection, light transmission of the glass is to consider. ▪ Structural parts – aluminum profile, steel, roof Skylights ▪ Light incidence can be checked by drawing a 30-degree angle below the skylight. ▪ All zones within this angle are sufficiently illuminated. ▪ No direct visual contact to the outside – recommended is a combination of skylights and lateral windows. 4  5/31/2024 Skylights ▪ Skylight emphasizes specific zones more effective than a lateral fenestration. Skylights ▪ Shape, arrangement, design of skylights depend on the usage and the desired daylight factor of the space below. ▪ Skylight centrally arranged or in regular intervals offer a particularly high uniform illumination. ▪ Illumination only through skylights: Working plane: ▪ Average daylight factor > 4% ▪ Oppressive performance – average daylight factor