Living Wall Health

Based upon typical living wall dimensions and previous work undertaken by the partners, a combination of industry standard soil moisture, temperature and electrical ​conductivity sensors and a new type of thermal moisture sensor for use in organic growth substrates were installed in both commercial and experimental living walls.

Sensor data from multiple measurement points across living walls was gathered and transmitted on an hourly basis using a custom configured CultinovaEDGE™ sensor system via a mobile Internet connection to a cloud data storage service. Measurement results were used to establish the relationship between irrigation scheduling, fertigation, plant and substrate type and wall environmental conditions - in particular heating due to building insulation performance and external urban heat-island effects.

Of particular interest was the relationship between temperature, irrigation, substrate type and unwanted nutrient build-up, the latter being as issue in certain types of wall design.

A specific challenge was the accurate sensing of the moisture level in wall using organic substrates where the substrate degraded (become porous) over the period of testing. In this case, traditional methods of measuring moisture using the dielectric constant of the substrate became problematic as voiding in the substrate increased.

To address this problem, a new type of thermal moisture sensor was utilised to measure volumetric water content, the first time this was undertaken in a living wall structure.

The results of the testing enabled imprvements to be made in living wall design and irrigation and fertigation scheduling, leading to an improvement in wall reliability and a reduction in living wall failure.