A system includes a plurality of carbon dioxide sensors each located in one of a plurality of spaces in a building and a plurality of air purification systems each located in one of the plurality of spaces and each including a UVC light source arranged within an internal space of a purification chamber and adapted to irradiate the internal space with UVC, an airflow system arranged to introduce environmental air from outside of the air purification system into the internal space of the purification chamber and expel purified air from the purification chamber back outside of the air purification system wherein each of the plurality of air purification systems is operable to purify air in response to an indication that an associated carbon dioxide sensor has sensed a level of carbon dioxide in excess of a predetermined threshold.

An air purification device including a flow passage through which air circulates; an electrical precipitator unit that is disposed in the flow passage and that includes a discharge electrode having a body unit and a corona discharge unit for corona discharge which protrudes from the body unit, and a collecting electrode disposed opposing the discharge electrode; an ozone removal unit that is disposed in the flow passage, and that is capable of removing ozone included in the circulating air, and a control unit that switches between a first mode in which air from which ozone has been removed is supplied from a downstream section of the flow passage to the outside, and a second mode in which air including ozone is supplied from the downstream section of the flow passage to the outside.

An electronic device includes a housing, a photocatalyst filter, at least one first sensor provided in the housing, a blower fan configured to introduce air into the housing, a light source configured to emit light to the photocatalyst filter, and a processor configured to control the blower fan and the light source, determine a degree of contamination of the photocatalyst filter based on a difference in sensor values between the at least one first sensor provided in the housing and at least one second sensor outside of the housing or a rate of change in sensor values between the at least one first sensor provided in the housing and the at least one second sensor outside the housing, and recycle the photocatalyst filter based on the determined degree of contamination of the photocatalyst filter.

A photocatalyst filter is provided. The photocatalyst filter includes: a base in which an internal space is formed. The internal space is permeable to fluid, and a plurality of photocatalyst beads are provided in the internal space, wherein a surface of the internal space is reflective.

A multi-functional air purification filter includes: a breathable support layer; a mesh layer provided on the breathable support layer; and a filter layer provided on the mesh layer, wherein at least a portion of the multi-functional air purification filter has a plurality of bends, and the mesh layer includes a coating layer of at least one of a photocatalytic material, an adsorption material, or a sterilizing material.

An air purification system includes a conduit extending between an inlet and an outlet, each in fluid communication with an enclosed environment. Ambient air from the enclosed environment enters the conduit via the inlet and treated air exits the conduit and enters the enclosed environment via the outlet. The system further includes a fibrous filter disposed within the conduit and configured to treat the ambient air thereby generating the treated air, and a renewal unit disposed within the conduit and configured to renew the fibrous filter.

Provided is an air cleaner, and more specifically, to an air cleaner in which a filter part using a photocatalyst is formed in a module type to facilitate replacement and cleaning and which includes an insert fan which is disposed inward from a suction port of a casing forming an exterior and including the suction port disposed at one side and a discharge port disposed at the other side, and suctions ambient air, a driving motor provided to be axially detachably coupled to the insert fan in a direction from the discharge port, and a suction unit fixing part in which an accommodation space, into which the insert fan and the driving motor are fixedly inserted in the direction from the suction port toward the discharge port and which is finished by inserting a cover member in the direction from the discharge port.

A filtering system includes a catalyst filter including a plurality of channels through which air is introduced, and a light-emitting device arranged to irradiate light to the catalyst filter for catalyst activation, where the light-emitting device includes a light source array including a plurality of first light sources corresponding one-to-one with the plurality of channels. Each of the plurality of first light sources may include a substrate, a first light-emitting device on the substrate, and a capsule which seals the first light-emitting device on the substrate. Only one first light-emitting device is provided in the capsule, or a second light-emitting device is further provided together with the first light-emitting device in the capsule.

Embodiments of the present invention include a filter element for decomposing contaminants including a substrate, and a photocatalytic composition comprising at least a photocatalyst and a co-catalyst. The embodiments of the present invention also includes a system for decomposing contaminants including a substrate, and a photocatalytic composition comprising at least a photocatalyst and a co-catalyst; and a method using the system.

Described herein are heterogeneous materials comprising a mixture of a first n-type semiconductor and a second n-type semiconductor. The first n-type semiconductor may be a single or plural phase TiO.sub.2 material. The second n-type semiconductor includes a metal titanate and/or a noble metal. Upon activation with ultraviolet light, the photocatalytic material mixtures described herein efficiently decompose volatile chemical compounds. Furthermore, the photocatalytic materials disclosed herein are observably more stable, relative to known semiconductor materials, to inactivation by deposition.