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

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.