Page 145 - AGC_EN_iBook

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LOuVRe CONtROLS
Aimed at controlling solar shading, the standard louvre control software used by COLT is based on light levels measured by a roof-mounted sensor (the system also includes an anemometer for measuring wind speed, a thermometer and a rain sensor).
In our case, the louvre control system has been extended to make the most of solar input in cold weather and nocturnal radiation cooling in hot weather, thus optimizing the building’s energy performance.
During the day, the louvres hit by the sun follow the sun’s path when natural light is above 15,000 lux from March to October and above 25,000 lux from November to February.
In cloudy weather, the four upmost louvres on each oor on the south and north facades are set in a horizontal position, acting as light shelves.
At night, the louvres are closed (parallel to the facade) from 18:00 to 08:00 or from 19:00 to 07:30 when the midday temperature is respectively below 10°C or 20°C to prevent the building cooling down, or opened from 20:00 to 07:00 when the midday tempera- ture exceeds 20°C to enable radiation cooling.
The controls can be overridden in the following cases (in order of priority):
– the louvres are opened in the case of re to allow the facades to be hosed down;
– the louvres are closed when wind speeds exceed 20 m/s
(75 km/h);
– the louvres are xed in their open position in the case of rain and when the outside temperature is below 3°C (risk of icing); – the louvres are closed for cleaning.The inside-facing sides of the louvres are cleaned by hand (via the walkways), while the outside-facing sides are cleaned by hose.
the slow movement of the louvres
An automatic camera is to be installed alternately at the south-east and south-west corners of the building to lm how the louvres move on sunny days at the solstices and equinoxes. It will take a picture every 30 seconds1.The rst lms will be made during the 2014 spring equinox, and will be available for viewing on the web- sites of AGC Glass Europe (www.agc-glass.eu) and Philippe Samyn and Partners (www.samynandpartners.com).
1 - One real-life hour is therefore captured in 5 seconds of lm, providing a short lm of 1 minute and 20 seconds for the 16 daylight hours of the summer solstice (21 June); 1 minute for the 12 daylight hours of the
21 march/September solstices; 40 seconds for the 8 daylight hours
of the winter solstice (21 December).