The literature offers some studies on the capacity of the greenery apparatus to decrease wind speed and regulate temperatures with the combination of the moisture retained by the plants and the air ...passing through them, but there is little on the maintenance of performance under particular weather conditions. The aim of this contribution is to verify the effectiveness of a vegetal façade in particularly windy conditions combined with rainy and/or high-irradiation events. The subject of the study is the enclosure of the Technology Innovation Centre for Development (itdUPM), on the Polytechnic University of Madrid, where a green wall prototype has been installed. For the purposes of the analysis, the environmental variables are examined and the monitoring data received from sensors positioned at the walls and skin of the insulated envelope are compared with the green face and without, comparing the differences in surface temperatures. These analyses are further examined by considering the correlation with different weather conditions. Experimentation shows a maintenance of performance, retaining an insulating capacity in all seasons, in both wind and rain, with results more evident in daylight hours. This contribute want to analyse the subtle variance between the performance of south and west facades. The strongest effect came forward during the summer season because the wall is affected by continuous irradiation on the south that is, also increased by hot weather.
•Database covering a 3-year period with continuous data monitoring through sensors.•Wind-barrier capacity of the green wall in both exposure of the walls.•Good insolation performance of green wall during rain and wind conditions.•Rain affects performance of green wall when wind blows perpendicular to the wall.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Intensifying the proportion of urban green infrastructure has been considered as one of the remedies for air pollution levels in cities, yet the impact of numerous vegetation types deployed in ...different built environments has to be fully synthesised and quantified. This review examined published literature on neighbourhood air quality modifications by green interventions. Studies were evaluated that discussed personal exposure to local sources of air pollution under the presence of vegetation in open road and built-up street canyon environments. Further, we critically evaluated the available literature to provide a better understanding of the interactions between vegetation and surrounding built-up environments and ascertain means of reducing local air pollution exposure using green infrastructure. The net effects of vegetation in each built-up environment are also summarised and possible recommendations for the future design of green infrastructure are proposed. In a street canyon environment, high-level vegetation canopies (trees) led to a deterioration in air quality, while low-level green infrastructure (hedges) improved air quality conditions. For open road conditions, wide, low porosity and tall vegetation leads to downwind pollutant reductions while gaps and high porosity vegetation could lead to no improvement or even deteriorated air quality. The review considers that generic recommendations can be provided for vegetation barriers in open road conditions. Green walls and roofs on building envelopes can also be used as effective air pollution abatement measures. The critical evaluation of the fundamental concepts and the amalgamation of key technical features of past studies by this review could assist urban planners to design and implement green infrastructures in the built environment.
Display omitted
•Green infrastructure can play a significant role in mitigating urban air pollution.•Air quality changes in local built environments due to vegetation are assessed.•Low-level hedges improves air quality in street canyons unlike high-level trees.•Green green walls and roofs are effective to reduce pollution in streets/open roads.•Prior design of green infrastructure should be performed for improving air quality.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This work reports on a new method to measure the absorption coefficient of a Living Green Wall (LGW) in-situ. A highly directional parametric transducer and acoustic intensity probe are used to make ...this method robust against background noise and unwanted reflections. This method is tested under controlled laboratory conditions and in-situ on a real green wall. The methods is compared favourably against impedance tube data obtained for porous media which properties are relatively easy to measure using a standard laboratory setup. The new method is an alternative to the ISO354-2003 and CEN/TS 1793-5:2016 standard methods to measure acoustic absorption of materials.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study aimed to evaluate the impact of the building’s green façade on regulating the indicators of daylight, visual comfort, heating and cooling load, and its features (such as the density of ...greenery and distance from the main facade). The effects of simulating 30 distinct green facade designs for various building fronts were examined. The findings reveal that altering the green facade’s distance (between 0 and 50 cm) had no discernible impact on the variables. The values of DA, UDImax, and cooling load have lowered by increasing density from 20 % to 100 %. The heating burden has grown, though. Higher densities of the green facade between different distances show a greater difference in the values of the tested variables than lower densities. For instance, at 100 % density, the UDImax value rose from the highest to lowest distance (0.50 cm) by 59.6 %, but at 20 % density, this shift was only 2.9 %.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Urban Heat Island (UHI) is a worldwide threat affecting building energy demand, public health, and energy security. Green wall deployment can simultaneously positively impact UHI and building energy ...demand depending on climate zones.
According to the different climate zones worldwide, the present systematic literature review (SLR) investigates the direct effects of green wall installation on building energy use and UHI. 1325 articles were screened, and 51, corresponding to 647 case studies, were selected after removing those with methodological or statistical heterogeneity. The effects of green wall deployment have been explored according to cooling and heating season, weather conditions, daytime, nighttime, green wall typology, green wall orientation, and application scale.
The performed analyses show that green walls: (1) can reduce heating and cooling building energy demand up to 16.5% and ∼51%, respectively, and mitigate UHI up to ∼5 °C in all the investigated climate zones; (2) can decrease to the greatest extent building energy needs when applied in low-density urban contexts where they can be installed on the entire building. Besides, when applied to a single façade, South orientation should be preferred in most climate zones to maximize building energy saving; (3) have the best UHI mitigating potential—up to 8 °C—in highly urbanized areas featured with narrow streets surrounded by high-rising buildings.
Altogether, green walls are a fit-all solution to reduce building energy demand and mitigate UHI, providing healthier living conditions. However, further research is necessary to include quantifiable and unquantifiable effects omitted in the current study.
•Green walls have been investigated in different climate zones.•The effect of green wall deployment on building energy use and UHI was explored.•Green wall deployment decreases building energy needs for space heating and cooling.•Green wall installation may reduce air temperature by up to 8 °C in street canyons.•Large-scale installation of green walls may fully mitigate UHI.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Achieving sustainable urban development requires a reorientation in the planning, management, and design of cities based on the use of cross-cutting solutions that can systematically address urban ...problems. The implementation of Nature-based Solutions (NBS) such as green walls in cities contributes to reducing the effects of a systemic issue: climate change. This field of research is constantly evolving, and there is a growing need for systematic analysis to understand the current scenario, identify gaps, and accelerate new lines of research. This review aims to demonstrate the impact of green walls on urban comfort by providing a systematic review of the state of the art in the field of temperature reduction and acoustic absorption, identifying the factors that influence urban comfort through the use of vegetation, and highlighting research gaps that can be further explored. The most relevant results have shown that the temperature reduction is mainly influenced by the shading capacity of the selected vegetation type, the evapotranspiration process of the plants, and the presence of substrate. Also, the acoustic absorption capacity is influenced to a greater extent by the system's configuration, the substrate's characteristics, and the vegetation's density. In both cases, the environmental conditions in which they are found can vary the impact to a greater or lesser extent. The results of this research are relevant for the implementation of green walls as a climate change mitigation tool in cities and the development of new research approaches.
•Green walls have a positive impact on thermal and acoustic urban comfort.•Shading and evapotranspiration reduce from 0.8 °C to 31 °C depending on the system configuration.•80% of the noise absorbed by a green wall is due to the presence of the substrate.•For dense vegetation, the absorption coefficient can increase by 0.2–0.3.•The evapotranspiration impacts temperature reduction if irrigation of 2.5 L/m2/day is ensured.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Thermal benefits of tropical climber green walls deserve more in-depth studies. A field experiment was designed in humid-subtropical Hong Kong to assess microclimatic effects of plant species, ...orientation and weather condition. In-situ measurements of air and surface temperatures of the indoor and outdoor environment were conducted respectively on the northeast and northwest oriented wirerope climber green walls with different air-gap depth. Adjacent bare walls were monitored as experimental controls. Days with sunny, cloudy and rainy weather in summer 2016 were chosen based on field-monitored incident solar radiation. The daytime and nighttime mean temperatures of the sampled days were evaluated statistically by t-test, analysis of variance (ANOVA) and Mann-Whitney U test. The best cooling benefits were realized at external building surface at 3.49, 0.52 and 1.19 °C respectively in sunny, cloudy and rainy weather during daytime. The respective values were 0.78, 0.05 and 0.03 °C during nighttime. Sunny weather featured more substantial external air and surface cooling, but indoor warming was recorded in cloudy and rainy weather. The northeast green wall achieved greater external air and surface cooling than the northwest one respectively by 0.38 and 0.77 °C in sunny weather. However, the northwest green wall registered higher external surface cooling by 0.47 °C at night. These results suggested the importance of research-informed green wall design for effective thermal regulation in urban areas. A deep air gap between the vegetation and the exterior building wall would provide more external surface cooling. Walls receiving higher solar exposure could be prioritized for greening.
•Green walls in subtropical Hong Kong were studied on summer sunny, cloudy, rainy days.•In daytime, northeast green wall cooled external surface by 3.5 °C on average.•At night, only external surface of northwest green wall was cooled significantly.•Orientation and air gap of northeast green wall enhanced external cooling.•Deep air gap of 1-m favored external wall surface cooling by subtropical green wall.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The main goal of this study is to assess the potential of green roofs and walls as a mitigation measure for the climate-change-driven growth of building energy consumption in extremely hot climates. ...A comprehensive, interdisciplinary methodology was developed that bridged climate change and building modeling. The residential building stock of Qatar was considered, with a two-story residential villa selected as a representative of the stock and consequently a case study. Weather scenarios were created for the years 2020, 2050, and 2080, and four building renovation scenarios were developed. The findings suggested that without any mitigation measures, residential building energy consumption in Qatar could increase by up to 9%, 17%, and 30% in 2020, 2050, and 2080, respectively. The addition of 5-cm expanded polystyrene and the installation of energy-efficient windows proved to be far more efficient than the addition of green walls and roofs under the climate conditions (30% reduction in energy consumption vs. 3%). Additionally, the environmental impact of green wall and roof maintenance, specific to Qatar, should be considered. However, in the final judgment, other positive effects of a green infrastructure (such as the effect on air quality, heat island effect, and health of the inhabitants) should be considered.
•Setpoint shift from 18°C to 22°C can save as much energy as insulation implementation.•EPS insulation is more effective than integrated greenery in extremely hot climate.•Extreme future temperatures will render EPS insulation, green roofs and green walls ineffective.•Increased future temperature will necessitate air conditioning in winters.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The objective of this techno-economic analysis (TEA) was to define the production cost of the microalga Tetraselmis suecica in a 1-ha plant made of “Green Wall Panel-II” (GWP®-II) photobioreactors. ...The study was based on an energy analysis carried out for a similar plant located in Tuscany (Italy) and considers the steps from inoculum preparation to the wet algal paste. Costs of equipment and materials were obtained from manufacturers and suppliers, while operating costs and output data (e.g. biomass composition and productivity) were collected during several years of trials at the Fotosintetica & Microbiologica S.r.l. facilities (Florence, Italy). Other data were obtained from Microalghe Camporosso S.r.l. (Imperia, Italy), where a commercial 1500-m2 GWP®-I plant is in operation and two 250-m2 GWP®-II modules were built and used in the framework of the EU project BIOFAT. This TEA shows that, given a productivity of 36tonnes per hectare per year, T. suecica biomass can be produced at a cost of €12.4kg−1 (dry weight). Using conservative assumptions it was estimated that at the 100-ha scale the cost will be €5.1kg−1. Locating the plant in more favorable climatic conditions (e.g. in Tunisia) will allow reaching 54tonnes per hectare annually and reducing cost to €6.2kg−1 at the 1-ha scale and to €3.2kg−1 at the 100-ha scale. The major cost factors are labor at 1-ha scale in Tuscany and capital expenses in all the other cases. This TEA confirms that microalgal technologies have high potential not only for high-value, but also for medium- and low-value products, while the production of biofuels, protein, food and feed seems currently out of reach. However, the global scenario of agriculture commodities is rapidly changing and other factors (e.g. sustainability), besides a pure economic evaluation, will assume greater importance in the future.
•In Tuscany, with a productivity of 36tonnesha−1 y−1, biomass cost is €12.4kg−1.•In Tunisia, with a productivity of 54tonnesha−1 y−1, biomass cost is €6.2kg−1.•At 100-ha scale in Tuscany biomass cost is €5.1kg−1.•At 100-ha scale in Tunisia biomass cost is €3.2kg−1.•Labor is major cost at 1-ha scale in Tuscany and CAPEX in all the other cases.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
During the last decade, vertical greenery systems are increasing their presence in building designs, providing several urban ecosystem services. One of them is the potential to provide energy savings ...in buildings, which develops an important role, however, data about its performance during winter periods is still scarce. Therefore, the main objective of this paper is to compare at real scale the thermal performance of two different vertical greenery systems implemented in experimental houses-like cubicles for both cooling and heating periods. A double-skin green facade has been installed in the first cubicle that uses deciduous creeper plants, while the second one is designed with green walls made with evergreen species. Finally, a third identical cubicle without any green coverage is used as reference. Two different types of experiments have been carried out to test the performance of the house like-cubicles. One consists of controlling the internal ambient temperature providing heating or cooling to maintain the desired comfort conditions. On the other hand, to study the thermal response of the construction system, the heating, ventilation and air conditioning system was disconnected and the cubicles were tested under free floating condition. First results showed a high potential for energy savings during cooling season for green wall (58.9%) and double-skin green facade (33.8%) in comparison to the reference system. On the other hand, for heating periods no extra energy consumption was observed for evergreen system.
•A seasonal evaluation of the energy consumption of vertical systems was performed.•Green walls showed higher heating and cooling performance than green facades.•A direct correlation between solar irradiation and energy savings was found.•The influence of vertical greenery systems according the orientation was studied.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
PDF
