This paper aims to examine the effects of two different climbing evergreen plants used as green vertical passive systems on a building wall . Experimental tests were carried out at the University of Bari ( Italy ), and several climatic parameters concerning the walls and the ambient conditions were analysed for estimating the variations of the walls surface temperature equipped with the greenery systems during several months .
Materials and methods
The tests were carried out from June 2014 to June 2015 at the experimental farm of the University of Bari in Valenzano ( Bari , Italy ), having latitude 41 ° 05 ’ N , longitude 16 ° 53 ’ E , altitude 85 m ASL . Three identical prototype of a commonly used vertical building closure in Mediterranean civil construction was built , made with perforated bricks joined with mortar . The walls face south and have a width of 1.00 m , a height of 1.55 m , and a thickness of 0.22 m . The bricks have a thickness of 0.20 m , an height of 0.25 m and a length of 0.25 m , a thermal conductivity λ ( following UNI EN 1745:2012 ) equal to 0.282 W m-1 K-1 , an average weight of the masonry work ( including plaster ) equal to 695 kg m-3 , a specific heat capacity C equal to 840 J kg-1 K-1 . The walls have been insulated on the backside setting up a sealed structure in order to better evaluate the influence of the vegetation layer on the wall ; the insulating structure was made of sheets of expanded polystyrene , having a thickness of 30 mm and a thermal conductivity of 0.037 Wm-2K-1 . Moreover , in order to reduce the effect of the incident solar radiation on the sealed structure , a blue shading net has been positioned onto the structure . The tests have taken into account the application of two different evergreen climbing plants as greenery vertical systems components ( Fig . 1 ): one wall was covered with Pandorea jasminoides variegated , the second with Rhyncospermum jasminoides ; a third wall was kept uncovered for control . A supporting structure made of an iron net was placed at a distance of 15 cm from the vertical wall . The plants were transplanted on June 18 , 2014 . The plants were irrigated with the drip method ; the fertilization was performed with N : P : K 12:12:12 .
Figure 1 : The three walls at the experimental field of the University of Bari ; the wall covered with Rhyncospermum jasminoides on the right , the wall with Pandorea jasminoides variegated on the mid and the uncovered control wall on the left .
Green walls for a sustainable control of building microclimate 859