slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Daylighting systems can be interesting to : PowerPoint Presentation
Download Presentation
Daylighting systems can be interesting to :

Loading in 2 Seconds...

play fullscreen
1 / 8

Daylighting systems can be interesting to : - PowerPoint PPT Presentation


  • 82 Views
  • Uploaded on

Daylighting systems can be interesting to : improve visual comfort in protecting from glare and direct insolation ; improve thermal comfort in protecting from solar gains. But also to : redirect daylight to under-lit zones; improve uniformity in the room.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Daylighting systems can be interesting to :' - aneko


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1
Daylighting systems can be interesting to :

improve visual comfort in protecting from glare and direct insolation;

improve thermal comfort in protecting from solar gains.

But also to :

redirect daylight to under-lit zones;

improve uniformity in the room.

To this end, there are two main groups of daylighting systems :

1. Daylighting systems with shadings

This kind of systems protects from:

Solar gains and overheating

Glare

Direct insolation

But also, sometimes, it can:

Occultates a room (for projections, …);

Ensures privacy of a room.

External shading systems are always more efficient than internal ones because they reduce solar heat gains in blocking radiation before it passes through the window.

2. Daylighting systems without shadings

These daylight systems are designed to redirect daylight to under-lit zones, away from the window.

Daylighting systems

Sources:

http://www.actual-size.com/blog/2009/12/tech-note-light-shelves/ (fig2)

http://www.velux.fr/particuliers/Produits/conduit_lumiere/default.aspx (fig3)

slide2
Daylighting systems with shadings

There are different types of solar protections: protections linked to the environment, architectural elements, added protections and protective glass windows.

1.1. Type of protections : position

The protection can be external or internal, but can also be integrated in the glazing.

 Internal blinds

Internal blinds is the most common way to control sun penetration.

Curtains

The first aim of curtains is generally to ensure the privacy of a room but can also be interesting to protect from glare.

Roller blinds

Roller blinds are a vertical version of curtains. They are composed of a cloth that is spread open in front of a window (Figure a). The protection is completely removable. The blind can be dropped or raised, partially or totally, as a function of needs in terms of solar contributions.

Venetian blinds

Venetian blinds can create intimacy and protect from glare but can, in a same time, let daylight penetrate in the room.

Venetian blinds are composed of slats that are mobile due to a system of cables or chains (Figure b). Protection depends on how the slats are oriented. Solar protection which can be modulated as a function of needs is the main property of blinds with orientable strips. This adaptation can be made by both withdrawing and inclining the slats.

Daylighting systems

Figure b

Figure a

Sources:

www.energies-renouvelable.com

slide3
 Integrated blinds

Integrated blinds offer a better protection against solar gains than internal blinds.

Venetian blinds

They are situated between the two glasses of a double glazing

Solar control glazing

Glazing can be heat absorbing or heat reflecting. Generally, they reduce heat gains but also penetrating light and modify the color of light.

Films

 External shades

External shades are the most efficient daylighting systems against solar gains. However, if they are permanent, they reduce daylight. But if they are not permanent, they are really useful because they do not reduce light availability in winter and are good glare and solar gains protection in summer. External shades which are automated according to sky conditions can irritate people if they are continuously adjusted. Moreover this kind of control is expensive and a maintenance is necessary.

Overhang (horizontal / vertical)

Can be solid or made of cloth (Figure c).

External louvers (horizontal / vertical)

Louvers are formed by a series of exterior strips, fixed or mobile. (Figure d).

Daylighting systems

Figure c

Figure d

Sources:

www.energies-renouvelable.com

slide4
Awning

Awnings, made of flexible and adjustable elements, opaque or diffusing, shade the glass window while keeping a view to the exterior possible (Figure e).

Italian blinds

Projected Italian blinds combine the properties of vertical rolling protections and horizontal protections (Figure f). They make it possible to conserve a certain natural lighting contribution.

Sun screen

The sun screen is made up of slats positioned on a chassis (Figure g).Its effectiveness depends on how its slats are oriented as well as the spaces between them.

Roller blinds

Roller blinds can also be external. They are composed of a cloth that is spread open in front of a window. The protection is completely removable. The blind can be dropped or raised, partially or totally, as a function of needs in terms of solar contributions.

Daylighting systems

Figure e

Figure f

Figure g

Sources:

Cliquez pour modifier les styles du texte du masque

Sources:

http://www.alibaba.com/product-gs/339991052/Window_Awning_

Gazebos_Awning_Outdoor_Furniture.html

slide5
1.2. Type of protections : mobility

The protection canbepermanent, fixed or mobile.

Permanent protection

Glazing can be a kind of permanent protection. Its degree of protection is constant over the year.

Fixed protection

Fixed protections can be integrated into the architecture of the building (wood overhang,…). This kind of protection is not mobile, but the sun evolving in the sky, the protection does not have the same effect over the year and over the day. So the degree of protection should vary over the year to be more effective against overheating during summer than in winter.

Mobile protection

Mobile protections are best adapted to the needs (glare protections, overheating protection or on the contrary benefit of solar gains) but their disadvantages are their control and their maintenance. The automation of the system offers advantages and disadvantages (generally automation brings a better adaptation but can become unbearable for the user).

1.3. Type of protections : transparency

Protections can have, in addition, a full (loggia, protecting glazing, architectural element, …) or an openwork design (venetian blinds, jalousie, curtains, …) which will influence the quantity of light penetrating in the room.

Daylighting systems

slide6
2. Solar penetration

There are various ways help daylight to penetrate deep into a building. During the pre-design stage of the architectural project atria and courtyards could be for example considered.

When the architecture of the building is already fixed, some daylighting systems can be integrated or added to the building:

Light shelves

A light shelf is an architectural element that allows daylight to penetrate deeply into a building.

Sun ducts

A solar duct is a system that serves to transmit direct solar light to the very heart of a building, in rooms that can not normally benefit from natural light.

Reflective window sills

Laser-cut panels

Holographic systems

Diffuse reflectors

Light scoops

Light baffles

Mirrored louvres

Prismatic glazing

Anidolic systems

Daylighting systems

Sources:

http://www.actual-size.com/blog/2009/12/tech-note-light-shelves/

www.energies-renouvelable.com

slide7
The Berlaymont building is a double ventilated glass façade building with glass louvres. The inside glazing layer is made of traditional double glazing and the outside façade is made of rotating glass louvres.

The louvres are made of two glazing leaves with a multi-layer film inside. The external face of the micro-perforated film is white, in order to reflect the daylight. The louvres inside colour is black, so as to allow the view towards outside. The louvres are organised in frames of 2m high and 3.3m width. Each frame contains 6 superimposed elements. The frames are organised by sectors, each of them including 3 frames that are interdependent for the louvres rotation command. The louvre control is a function of the sun position (date and time); the louvre location on the façade (orientation et height) and information collected by the meteorological sensors located on the roof (wind, horizontal illuminance, rain and temperature).

The louvres are tilted according to these parameters and make function either of shading (from 0° to 60°) or of reflectors, in order to increase the luminous penetration (110°), when there is no direct sun. For the shading function, the louvres are oriented perpendicularly to the sun. As the rotating movement is only possible by 10° step, the louvre will be perpendicular to the sun rays, with 5° accuracy. Under cloudy sky, the daylight factor values are strongly dependent on the louvres slope. When the louvre slope is equal to 110°, the daylight factor increases by 33% compared to the value obtained with a 90° slope and by 100% compared to the value obtained with a 0° slope. The luminous direct transmittance of the louvre is about 70%. This value is constant as the louvre stays perpendicular to the sun.

Daylighting systems

Sources:

http://www-energie.arch.ucl.ac.be/eclairage/usexemple.htm#ancre02

Sources:

http://www-energie.arch.ucl.ac.be/eclairage/usexemple.htm

slide8
International Energy Agency, "Daylight in Buildings : a source book on daylighting systems and components", IEA SHC Task 21 report, 2000.(available on http://www.iea-shc.org/task21/index.html)

David Rennie and ForoutanParand, Environmental design guide for naturally ventilated and daylit office, BRE, 1998.

Daylighting systems

Sources:

http://www.ecbcs.org/annexes/annex29.htm