(A) Photocatalytic and ordinary tiles [81]; (B) manufacturing and assembling processes of PC-Trombe wall system [82]; (C) an air cleaner (AX7000, Samsung) equipped with two 001-TNT filter units and 30 UV-LEDs (Seoul Viosys, CUN66A1B) [25]; (D) schematic diagrams of the VUV-PCO air purifier [83]; (E) photocatalytic reactor of biological sampling system (left) and reactor frontal view (right) [84]; (F) a test chamber (8 m³) with the air purifier for VOC removal experiments [85]; (G) schematic representation of the photocatalytic air purifier prototype [86].