Seasonal influence of leaf area index (LAI) on the energy performance of a green facade

Pérez, Gabriel; Coma, Julià; Chàfer, Marta; Cabeza, Luisa F.

doi:10.1016/j.buildenv.2021.108497

Cited by 44 publications

(23 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Many researchers also agree that, among all these factors, LAI is the most crucial parameter [19,40,45]. Regarding the beneficial cooling effect provided in warm periods, as highlighted in our research, also other studies stated the influence of LAI on the potential cooling achievable by shading and evapotranspiration [19,40,45,46]. Moreover, it is suggested that there is a threshold value of LAI beyond which its influence on the cooling effect is no longer significant [46].…”

Section: Discussionsupporting

confidence: 79%

“…It is commonly recognized that plant characteristics influence the thermal functioning of VGSs [28,29]. Many researchers also agree that, among all these factors, LAI is the most crucial parameter [19,40,45]. Regarding the beneficial cooling effect provided in warm periods, as highlighted in our research, also other studies stated the influence of LAI on the potential cooling achievable by shading and evapotranspiration [19,40,45,46].…”

Section: Discussionsupporting

confidence: 74%

“…LWs use plants that are placed into continuous permeable screens or in modular elements. These contain the growing medium or hydroponic systems, held by frame structures fixed to the building wall [19]. LWs, which require higher initial investment and operating costs and intensive maintenance, have higher potential impacts on the environment than GFs [20,21].…”

Section: Introductionmentioning

confidence: 99%

“…LAI is a dimensionless quantity, defined as the leaf cross-sectional area per unit covered area. LAI has been recently used for comparing several types of plants used in GFs, for monitoring plant growth and maturity, and for evaluating energy saving seasonal variation [19,30,31]. Wong et al [32] found a linear correlation between LAI and shading coefficient values for different VGSs.…”

Section: Introductionmentioning

confidence: 99%

“…They established a simple procedure of measuring LAI and finally related it to the energy savings provided by the GF. Pérez et al [19] characterized, through continuous monitoring, the annual evolution of LAI for an indirect GF made up of a Boston ivy deciduous climber plant in Mediterranean continental climate. The impact of facade orientation and LAI on the wall external surface temperature and the energy consumption were addressed and the results confirmed their direct dependance on LAI evolution across the seasons.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Effect of Leaf Area Index on Green Facade Thermal Performance in Buildings

et al. 2022

View full text Add to dashboard Cite

Green facades applied on a building’s envelope allow achieving the building’s passive thermal control and energy consumption reduction. These are complex systems and many site- and plant-specific parameters influence their energy behavior. The leaf area index (LAI) is a relevant plant characteristic to consider. Solar shading and latent heat loss of plant evapotranspiration are the two main cooling mechanisms. The aim of this study was to assess the cooling effect provided by an evergreen south oriented green facade in summer in a Mediterranean area and to investigate what happens when LAI changes. Experimental data were used to calculate the cooling effect provided by the facade. Simulations with different LAI values were performed to determine the related cooling effect. The canopy solar transmissivity decreased by 54% for every LAI unit increase. LAI significantly influenced the green facade cooling performance. As LAI increased, solar shading and latent heat increased; this was relevant until an upper limit value of 6. An exponential equation to calculate the mean extinction coefficient (km), and a polynomial relationship, with very good agreement, were proposed to calculate shading and latent heat as function of LAI. The findings of this research can effectively contribute to fill still existing gaps on green facades’ energy performance and to the energy simulation of buildings equipped with them.

show abstract