Influence of green walls on indoor air quality. A comparative analysis based on chosen parameters - Formaldehyde, Particulate Matters, and moulds

Abstract

The use of plants as a phytoremediation tool for air pollution in indoor environments has become more and more popular since the 1980s (Fleck et al., 2020). Humans spending a chunk of their time indoor (Fermo et al., 2021), and indoor air quality being of high stakes, the deployment of Green walls in indoor spaces (Liu et al., 2018) abounds today. This research project was aimed at finding out what the real effect of passive green walls is on pollutants that matter as far as indoor air quality is concerned. Given its scope, the project was split into four segmented but related parts to allow the participants to focus on specific interests. In this one, the focus was put on Formaldehyde, Particulate Matters, and moulds. The identification of the types of moulds was not worked on as the study was only based on general concentrations. The research was done in an experimental building in which conditions of an indoor space are simulated with desired temperature, humidity conditions as required to achieve one thing or the other. Results notwithstanding the non-perfect comparability of the observations due to relatively different conditions show that formaldehyde concentrations in the chamber dropped after the installation of the green walls. Mould concentration on the hand increased but stayed within generally acceptable limits. Concerning PMs, the widely available literature on how green walls help reduce PMs concentrations did not materialize. We suspected however that the instrument used in monitoring PM levels was sensible to the augmentation of moulds and therefore might have been the cause of that observation.