Room air cleansing using hydroponic plants

Apparatus for cleansing air, wherein:

• the apparatus includes a plant-box, and the plant-box has a front wall, and enclosing walls, which enclose and define a plenum chamber;
• the plenum has an air outlet port, in one of the walls;
• the apparatus includes a powered fan, which is so disposed in the apparatus as to be effective to receive air from the plenum, through the air outlet port, and to discharge the air;
• the front wall of the plant-box includes a root matrix panel, which is made from air-permeable material, and is so arranged in the apparatus as to allow air to pass therethrough, into the plenum;
• the material of the root matrix panel is structurally solid, and is of such porosity or fibrosity as to enable the roots of plants to infiltrate thereinto, and to provide physical and mechanical anchorage and support for the roots and foliage of the said plants;
• the apparatus includes a mass of plants, the roots of which are infiltrated into and embedded in the material of the root matrix panel;
• the material of the root matrix panel of the plant-box is substantially inert with respect to microbiological actions and reactions associated with the mass of plants;
• the apparatus includes a hydroponic water and nutrient circulation system;
• the said system includes a storage tank containing hydroponic water, and a water outlet;
• the water outlet is positioned above the root matrix panel, and is so arranged that hydroponic water passes out from the outlet, down onto the root matrix panel;
• the apparatus is so arranged that hydroponic water trickles down, from the outlet, over and through the material of the root matrix panel, and over and through the roots of the plants embedded therein;
• the system is so arranged that the roots of the mass of plants are kept substantially constantly wetted by the hydroponic water;
• the system includes means for supplying nutrients for supporting and making viable the mass of plants into the hydroponic water;
• the root matrix panel of the front wall of the plant-box has a thickness T cm, as measured in the direction in which air passes through the panel, and the root matrix panel has a permeability area A sq cm, through which the air passes, as measured perpendicularly to the thickness T;
• the root matrix panel is disposed with the said area A of the panel having sufficient verticality that
• (a) the hydroponic water passes downwards, under gravity, over and through the material of the panel, and
• (b) air passes through the panel, into the plenum, in a direction that is at least roughly horizontal.