COOLING, LIGHTING AND ACOUSTIC STRATEGIES

Passive strategies through a limitation of operative temperature and humidity level in order to limit the external heat gains toward strategies to activate natural cooling potential like the ground, the sky and the outside air and in order to reduce the conflict between desired daylight luminance and solar heat gains.

1. Heat protection by shading with PV cells on the external roof in order to reduce the solar gains on external walls (limiting short waves radiation).
2. Reflective outdoor surfaces to reject short waves radiation (directs and diffuses).
3. Ventilated lightweight roof to provide shading to the buildings yet allowing the venting and dispersion of heat caused by absorbed solar radiation, long waves radiations and internal gains. (stratification of the hot air).
4. Dispersion of long waves radiations at night throughout the oriented panels.
5. Sandstones high thermal mass to buffer temperature fluctuations (temperature amplitude 5°C to 25° C in winter, 30°C to 45°C in summer).
6. Statification of hot air and evacuation by night-time ventilation.
7. Thermal mass to absorbe internal gains and recharge during night-time ventilation.
8. Natural recooling of the thermal mass due to night time temperature outdoor low enough (and when acceptable level of humidity).

9. Night-time cross ventilation when external temperature is below 30°C (for acceptable levels of humidity) or with precooling air (1ac/h) in case of high humidity.
10. Reduction of infiltration during the hot summer months (0,2 ac/h), conditioning system in use.
11. Collected condensates (during high humidity night periods in summer or haze periods) as water resource for conditioning material or water tanks placed in the basement.
12. Conditioning systems are powered by the PV cells.
13. Flaps on ventilation openings in case of sand storms or hot winds.
14. Natural ventilation through the courtyards in winter (night and day).
15. Conditioning by-pass system depending on season, temperature and humidity conditions.
16. Absorptive dehumidification chiller by desiccant liquid placed in the fresh air supply flow in combination with a sensible cooling recovery by runaround system (evacuated solar collectors) and adiabatic cooling.
17. Forced cross ventilation due to the thermal chimney effect supported by the temperature difference between inside and outside temperature and supported by the thermal mass of the chimney which stores solar energy and which uses this heat capacity to increase the exhaust air temperature to force the night-time cross ventilation.

18. Active chilled beams as radiant cooling for the space (being the most comfortable and energy efficient system). Risk of condensation is controlled by regulation of inlet air while refrigeration is in operation.
19. Water cooled panels activated during night-time to dissipate the heat from chilled beam conditioning system of by long waves radiations into the sky.
20. Structural foundations piles coupled with a water pipes system to recool the chillers to the 20°C soil temperature (200m deep).
21. Domestic hot water solar panels.
22. Sprayer (natural cooling of dirty air) in summer day. Sprayer will be cut during high humidity night in summer.
23. Cold storage during winter and water cooled panel activated during night-time to disperse the heat of water pipes system.
24. Closed buildings (windows and natural ventilations) during hot and wet periods in summer.
25. Mechanical ventilation for hygienic air change and evacuate internal gains.
26. Light ducts to provide daylight on the base of the courtyards.
27. Deflective panels to reduce light luminance from the light ducts to the courtyard.
28. Roof protected against direct radiation from the sun and diffusion through the specifics holes of the light ducts.
29. Gardens to evaporative flows and refreshing dirty air.

30. Moucharabieh woods and plaster façades to control daylight during the year and to control humidity from the courtyards when the buildings are open to the courtyards in winter.
31. High efficiency light sources (100 lm/W).
32. Maximum efficient equipment for artificial lighting below 10w/m2.
33. Integrated daylight detectors to control of artificial lighting above luminance level of 400 lux.
34. Laptop computers with LCD screens and energy labels for appliances.
35. Floor, wall and ceiling materials with adapted reflectance in order to diffuse homogeneous luminance.
36. Optimised daylight factor and high selective glazing.
37. Floors and walls with massive stones as good noise insulation due to the mass low.
38. Highly selective glass to reduce noise conductions through the courtyard façades.
39. Stone ceiling with specific geometry to control sounds reflection and micro perforation to absorb specific sounds.
40. Perforated façades to absorb external sounds and complex geometry to disperse sounds. summer day - hot and dry = 30 to 40°C and 30% to 70% RH. summer night - hot and wet = 25 to 35°C and 60% to 90% RH. wind (wind tower) sun (solar tower) water