Sick building syndrome (SBS) refers to a well-defined symptom pattern that manifests itself in a large number of buildings [...]
Numerous investigations of buildings where health or comfort problems were reported found that the predominant problem (in almost half of the cases) was inadequate ventilation.

Many chemicals in indoor air are known or suspected to cause irritation or stimulation of the sensory system and can lead to sensory discomfort and other symptoms commonly seen in SBS. Some studies conducted in offices and other public-use buildings in several countries have found that the incidence of disorders among occupants ranges from 15% to 50%.

Excerpt from the website of the Italian Ministry of Health.

A typical heating, ventilation and air conditioning (HVAC) system is generally responsible for about 40% of a building's total energy consumption. Mechanical ventilation systems are the simplest and most commonly used method to control air and filter suspended particles in enclosed spaces. However, this technique does not retain the gasses and the filters gradually become saturated by the particles. As a result, they tend to lose pressure and greatly reduce their separation efficiency over time until the filter needs to be replaced. Exhausted filters then become new sources of contamination due to the accumulation of dust, which favors the growth of harmful microorganisms.

In 2016, large buildings were responsible for about 41% of energy consumption, 60% of electricity consumption and 36% of CO2 emissions.

The application of a breathing green wall as a biofilter can save about 60% of energy in summer and 50% in winter, guaranteeing significant energy savings in HVAC systems and a reduced environmental impact of the building.

We have estimated that 1 square meter of the Aura wall, with more than 50 plants installed, can absorb 5.5 g of CO2 per hour.