EVALUATION OF HEAT BALANCE OF WALL GREENING(Environmental Engineering)

Abstract

In order to 己valuate the mitigating effects of urban heat island l 〕 y wall greening ， an experiment to characterize the evaporation effect of a greening system and to quantify its heat balance was carried out ， At heat balance analysis， sensible heat flux is calculated using heat transfer coef 丘cient estimated by measurements with SAT （ Sol − air Temperamre ） meter ． As a result， it is confirmed that wall greening has the mitigating effects ofheat island due to the sensible heat reduction by consuming the latent heat by evapotranspiration 、 And it is able to evaluate the effects of wa 】 1 greening system using evaporation ef［ iciency as an index ofevapotranspiration ability ． 1． は じ め に

Transpiration cooling effect of climber greenwall with an air gap on indoor thermal environment

“…Several studies have attempted to distinguish and quantify the transpiration cooling effect by comparing GWs against nonbiological shading devices (Hagishima et al, 2005;Misaka et al, 2006;Stec et al, 2005;Suzuki et al, 2007). However, the nonbiological shading devices used in these studies possessed thermal properties different from real plants, and data did not take vegetation coverage into consideration.…”

“…Stec et al (2005) showed, using a total building simulation, that a double skin façade with plants reduced cooling energy consumption by about 19% as compared to the one with blinds instead of plants. Hagishima et al (2005), Misaka et al (2006), and Suzuki et al (2007) used artificial plastic plants to measure sensible heat flux and determined the convective heat transfer coefficient, enabling the calculation of latent heat flux. However, thermal properties, such as a solar absorptivity and specific heat, are quite different between these artificial materials and real plants; therefore, these studies may have overestimated the transpiration cooling effect.…”