Final Program EXPRES 2012 - Conferences

But can we use the human body sweat evaporationeffect on buildings? There are buildings for which itmay be said that they use the effect of waterevaporation for their cooling, as in the case of a man’ssweating.It is an old practice to put water sprinklers on theroofs of large surfaces, and use them at high outsidetemperatures, when the sun radiates intensively. Theroof is so moistened, and because of the heat absorbedby the outer roof surface and the air layer next to it,water evaporation occurs, and the roof temperature islowered. Pools are also installed on roofs of multistoreyresidential and business buildings.The idea to let the water flow down a buildingfaçade, an imitation of human sweating, is an option ina modern architecture, in case of glass facades asfrequently used elements in contemporary buildings,probably more for visual effects, but also as a way toget some kind natural reaction. Flowers, grass, but alsowater as an especially important element in somecultures becomes a repeatedly used elements in themodern architectural expression -.most often inside thelarge halls, restaurants, atriums.76074072070068066064062060058056054010:0410:1910:3310:4811:0211:1611:3111:4512:00a b c dFigure 6. Measurements results of solar radiationtransmission effects on dry and wet glass under the angle of45 deg. . .12:14. The measurements provided above the glass with an angle of45 degrees are presented on the Figure 6. showing solarradiation intensity through dry and wet glass. Uniform waterflow above glass façade has a lower solar radiationtransmittance for 10-15% than an ordinary dry glass. Andwhen the water flow is turbulent and disturbed, even 25-30%,depending on water quantity.The temperature of a glass under water flow was about 10Clower than the glass without a water above it. The temperaturedifference on a water inlet and outlet was very small, as thedistance between them was 1.5m only.On the figure 7 is the model of glass above which is lowingwater. The thermo-vision made photo is showing temperaturedifferences in a water film. The values of these temperaturesare separately given for two horizontal sections and onevertical, with the temperatures of the upper and downhorizontal sections as well as through vertical section. Thetemperature increase was measured 1,5 C.12:2812:4312:5713:1213:2613:4013:5514:09Figure 5. Water down flowing above glass envelope of the BritishpavilionThere are several buildings around the world withwater flowing down the glass vertical or the inclinedfacade. One of such examples is again the building ofthe British pavilion in Seville (Figure 4.). Such façadehas smaller coefficient of the solar radiationtransmission, and with the water layer, due to itsevaporation, the temperature next to the façade issignificantly lower than the outside one, reducing sothe heat gain from the solar radiation, as well as fromtemperature difference between the outside and theinside.Figure 7. The model of glass façade wall above whichis flowing thin layer of water11