Thermal Effects Of Three Vertical Greening Systems On Inside And Outside Of The Buildings

In recent years,the urban heat island effect has intensified,the urban greening land is becoming more and more tense.How to develop new green space is one of the problems that urban construction must face.Vertical greening is a viable way to manually expand the green space,and vertical greening has a certain contribution to the cooling of building walls and the improvement of indoor microclimate.In this study,the bare wall was used as the blank control,Three vertical greenery systems(VGSs)were installed,the block wall,the module wall,the planting wall,which were planted Schefflera arboricola.In addition,another the block wall was planted Duranta erecta 'Golden Leaves'.Under different weather conditions,four VGSs on the outer surface,inner surface and internal heat of the building were monitored to explore the effects of different VGSs types and different vertical greening plants.Research indicates:(1)4 VGSs can increase the relative humidity of the o uter surface,reduce the daily average temperature and daily temperature fluctuation range,the cooling effect of4 VGSs are better than that of bare wall.(2)Different VGSs types have different e ffects on the building's heat.In terms of the outer surface of the test room,the planting wall have the best cooling efficiency,and the cooling mean reaches 10.5?,which is higher than that of the block wall(9.1?)and the module wall(8.8?).In terms of the inner surface and internal of the test room,The block wall have the best cooling efficiency,which the cooling mean are 3.9?and 2.7?,higher than that ofthe planting wall(3.0?and 1.9?),higher than that of the module wall(2.8? and 2.1?).In sunny and cloudy days,the surface temperature of the planting wall is larger than that of the block wall and the module wall.However,there was no significant difference in rainy days.In terms of the inner surface and internal of the test room,the cooling efficiency of the block wall was larger than that of the module wall and the planting wall,and the cooling efficiency between the module wall and the planting wall was no significantdifference.(3)The cooling effect of different vertical greening plants on the heat of the block wall weredifferent.The temperature of planting Schefflera arboricola is more than planting Duranta erecta 'Golden Leaves' in the block wall.In sunny days,the temperature of the outer surface,inner surface and the internal of the test room,the cooling mean of Schefflera arboricola and Duranta erecta 'Golden Leaves' were 9.1?and 6.5?,3.9?and 3.5?,2.7? and 2.2?respectively.In sunny days,In terms of the outer surface of the block wall,the cooling effect of planting Schefflera arboricola is larger than that ofplanting Duranta erecta 'Golden Leaves',and the difference is significant.For the inner and the inside,the cooling effect of planting Schefflera arboricola was similar to that of planting Duranta erecta 'Golden Leaves',and the difference was not significant.In cloudy and rainy days,the temperature of planting Schefflera arboricola was similar to that of planting Duranta erecta 'Golden Leaves',the difference was not significant.(4)The external surface temperature of the test room is positively corre lated with the air temperature and the average solar radiation intensity,and is negatively correlated with the relative humidity of the air,which has weak correlation with the wind speed.The internal surface and internal temperatures of the test room are positively correlated with the air temperature and have weak correlation withthe average solar radiation intensity and wind speed.The vertical green wall can reduce the influence of air temperature,air relative humidity and solar average radiation intensity on the external surface temperature and relative humidity of the test room.Block wall and planting wall were smaller than the module wall by the outside air temperature and relative humidity.In the block wall,planting Schefflera arboricola was smaller than planting Duranta erecta 'Golden Leaves' by the outside air temperature and rela tive humidity.(5)In terms of three VGSs cost,block wall system(616.7 ?/m2)<module wall system(775.2 ?/m2)<planting wall system(805.2 ?/m2).The VGSs have obvious improvement effect on the surface temperature and humidity,inner surface and interna l temperature of the building.The VGSs have the largest cooling efficiency especially in sunny days.The cooling effect of different plants were different.Planting Schefflera arboricola in the block wall show higher cooling capacities than that of planting Duranta erecta 'Golden Leaves'.For the indoor,the block wall show higheset cooling capacities,the planting wall followed secondly,the module wall is worst.Moreover,the block wall has lowest cost in the 3VGSs,which is a worthy ofthe promotion of the VGSs.