AA SED 2006 2007-autonomous sustainable island
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The document discusses the evaporative cooling potential in Abu Dhabi. It finds that evaporative cooling can be effective when the wet bulb temperature is below 24°C and dry bulb temperature below 44°C. However, based on weather data analysis, evaporative cooling has limited potential in Abu Dhabi during hot periods from May to September when temperatures are between 30-35°C. It may be applicable during milder periods from December to March when temperatures are 20-23°C. Specifically in May, evaporative cooling will not work due to high relative humidity above 65%, even though wet and dry bulb temperatures allow it. The document thus concludes evaporative cooling has some passive cooling potential for outdoor and semi-outdoor
AA SED 2006 2007-autonomous sustainable island
- 64. 53 Figure 71: Abu Dhabi yearly temperature fluctuations. Source:Yannas Figure 70: May, dry and wet bulb and Rh relationship Source:Yannas Evaporative Cooling potentials Principally, evaporative cooling can be an effective passive cooling strategy when the wet bulb temperature is below 24ºC and the dry bulb temperature is below 44ºC( Yannas.) temperature drop of 3-4K relative to the outdoor dry-bulb. Based on the weather data analysis, in Abu Dhabi indirect evaporative systems have a limiting potential due to high dry bulb and wet bulb temperature during the hot period when the outside temperature is between 30 -35ºC. It might have limited applicability during the mild period (December to March ) when the daily average outdoor air temperatures is between 20-23ºC. Figure 71. From Figure 70, It is understood that In May, though dry and wet bulb temperaturse are with in Evaporative cooling range due to high RH value 65% and above, evaporative cooling will not eb affective. Based on all the principles Evaporative cooling might have some passive cooling potential and can be sued on the outdoor and semi outdoor spaces of the islet, during the mild period Jan to March, November , December. This hypothesis needs to be explored further. Givoni gives the limits for applicability at wet-bulb of 25ºC and dry-bulb of 46ºC, with (Givoni 1994:14) Figure 69:Indirect passive Cooling with Water in the Gulf. Source: Farah Naz 14.3 Evaporative Cooling Potential: 14. Passive Cooling Strategies: