Quantitative Evaluation of Mitigation Effect for Thermal Load of Solar Radiation Through the Glass Window by Wall Greening

Abstract

In this study, the wall greening by vine with a simple net was constructed on the west side wall. For the purpose of quantitative evaluation for mitigation effect of thermal load by using wall greening, the model to estimate the solar radiation through the glass window was discussed. Estimated cumulative thermal load of solar radiation was corresponding to observed value. The mean error of transmissivity estimation every two hours from 9 AM to 5 PM was 0.90%, 0.89%, 2.02% and 3.17%, respectively. Our model tended to overestimate the sun-shading effect by wall greening from 3PM to 5PM in sparsity leaf condition of which the LAI was under 1.0. The relationship between the LAI of greening wall and the mean of solar radiation transmissivity through the window has a negative correlation. Each same time period, observed mean of solar radiation transmissivity through the window was reduced 4.40%, 4.15%, 6.53% and 10.13%, respectively with increase of LAI per unit.

Quantitative assessment of plant water consumption in the summer after creating a green curtain by using ivy morning glory on a south-facing wall

“…Ivy morning glory increased in popularity in recent years as a suitable plant that is suitable for green curtains. In those our study, an elementary school with green walls on the south side exhibited a reduction in total thermal load during the day by 75 % to 78 % (Takayama et al, 2011(Takayama et al, , 2012. Although wall greening is useful for mitigating heat, the spread of greenery in urban areas generates an increased demand for water resources.…”

“…In general, the leaf area index LAI g is equal to the leaf area index (LAI). The purpose of using LAI g here was to distinguish it from LAI, which was used as the leaf area per unit of building wall area in related research (Takayama et al, 2011;Takayama et al, 2012) that discussed quantifying the effect of reducing the heat load by wall greening 3.3 Calculation of the reference evapotranspiration and water consumption In general, the water consumption of greening plants is mainly determined by climatological factors and the degree of plant growth. We examined the relationship between daily water consumption and some climatological factors or LAI g .…”

A Simple Method to Evaluate Adaptation Measures for Urban Heat Island

“…From the heat countermeasure guidelines by the Japanese Ministry of Environment [5] Green shade [16]…”