Analysis for the effect of roof greening in warehouse by mean of simulation

Abstract

Roof greening in warehouse is expected not only to improve the environment but also to reduce the heat island effects by evapotranspiration from the soil and plants. Effects of roof greening on room air temperature in warehouse and cooling load in summer were investigated using simulation model. In this study, two types of roof greening were assumed, roof greening with soil (greening type 1) and without soil (greening type 2). Our results showed that room air temperature in warehouse was decreased by 18.1°C for greening type 1 and 9.5°C for greening type 2 compared with no roof greening. In greening type 1, the room air temperature was decreased with increasing the coefficient of transpiration from the plants. The maximum room air temperature was decreased with increasing the light interception ratio and decrease in room air temperature with increasing light interception ratio in greening type 2 was larger than that in greening type 1. Daily cooling load with greening type 1 was lower than that with greening type 2. Electricity cost for air-conditioning in summer was reduced by 135 yen for greening type 1 and 63 yen for greening type 2 compared with that for no greening when set temperature for cooling was 26°C. These results suggested that roof greening with soil can maintain lower air temperature in warehouse and save more cooling load than that without soil due to the latent heat with evaporative cooling from the soil.