Beyond green façades: active air-cooling vertical gardens

Purpose

Vertical gardens offer multiple benefits in urban environments, including passive cooling services. Previous research explored the use of “active vertical gardens” as potential evaporative air-cooling units by developing a mathematical model based on the FAO-56 Penman Monteith equation. Further research showed that active vertical gardens function best by creating an airflow in the cavity behind the garden such that air is cooled by flowing over the water-saturated garden substrate. The purpose of this paper is to improve the quantification of active vertical garden performance.

Design/methodology/approach

A building-incorporated vertical garden was built in Quito, Ecuador, with an air inlet at the top of the garden, an air cavity behind the garden and where air was expelled from the base. Measurements were made of air temperature, humidity and velocity at the air inlet and outlet.

Findings

The active vertical garden cooled the air by an average of 8.1 °C with an average cooling capacity of 682.8 W. Including the effects of pre-cooling at the garden inlet, the garden cooled the air by an average of 14.3 °C with an average cooling capacity of 1,203.2 W.

Originality/value

The results are promising and support the potential for active vertical gardens to be incorporated into building services and climate control.