Problem:

Cities are getting more polluted by the day, insects are dying and you can’t call a big city quiet, but there is no solution for people with limited money to fight all 3 problems.

Solution:

A cheap D.I.Y. moss wall for noise absorption, air filtration in cities and a small insect hotel.

Explanation:

The wall is built in a simple and cost-effective way, which allows other people to reconstruct it, if they have the blueprint and the materials, latter can be bought in any hardware store. The moss wall consists of a chipboard with a hydrophilic fabric attached to the board and a coconut mat on top of that. We use the coconut mat to facilitate the growth of the moss, because it is not fixed in the vertical from the beginning. Additionally, it stores about 1 ml of water per cm². The moss we used is silver green bryum moss, because it subsists on nitrogen(1), which it obtains from nitrogen oxides, stores CO₂ and indicates heavy metals, all of these things can be found in car emissions, making the moss perfect for our project. The needed water comes from a cistern, connected to a dropper and gets transported to the moss using the capillary forces of the hydrophilic fabric, the coconut mat absorbs the water and the moss can pull it from there. On warm days the dropper can be set to a summer mode, reducing the used water, furthermore the moss does not require much water and can easily survive in dry environments (2). It is intended to have only houseleek(s?) on the north side of buildings, a mix of houseleek(s) and moss on the west and east sides, and only moss on the south side. Also attached to the board are a piece of wire fence, which helps the moss grow onto the coconut mat and prevents storm damage, and an insect hotel with different hole sizes for different insects. Because one of the goals was noise absorption, we conducted some test and learnt that the wall can absorb up to 25% of the noise, at 500-520Hz.

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