Experimental investigation on the energy performance of Living Walls in a temperate climate

• We performed field measurements of three outdoor Living Walls.
• We compared results of the field measurements.
• Living Wall summer outgoing heat flux is higher than Bare wall outgoing heat flux.

Living Walls, a type of vertical greenery system, are relatively light structures for architectural green cladding. They embed a thick curtain of plants nurtured by an automated watering system. Three Living Wall field tests are presented for investigating potential effects of the energy behavior on building envelopes. In particular, Living Walls were monitored in a Mediterranean temperate climate context at the latitudes of Northern and Central Italy.As a result, the dependence on the solar radiation forcing came out clearly. During sunny days, difference in temperature (monitored on the external surface) between the bare wall and the covered wall ranges from a minimum of 12 °C (case C) to a maximum of 20 °C (case A). The analysis was extended also to heat flux. The incoming (positive) heat flux through the bare wall was found to be higher compared to the Living Wall. Considering an overall thermal balance during the monitoring period, the outgoing heat flux through the Living Wall was higher. These results indicate that the use of green architectural cladding can significantly contribute to cooling energy reduction and offer a valuable solution for retrofitting existing buildings.