Abstract: An ozone generator with a high voltage electrode and at least one counter electrode which limit a gap in which at least one dielectric is arranged and which is flowed through by a gas flow in the direction of flow. The high voltage electrode and the at least one counter electrode are provided with a connection for an electrical power supply to generate silent discharges. A fabric is arranged in the gas flow. The fabric includes a material combination including at least one wire and at least one electrically non-conductive fiber.

Abstract: A filter medium is provided with a first filter layer that retains particles and a second filter layer provided with an antimicrobial material and an anti-allergenic material. The anti-allergenic material contains polyphenols. The filter medium is designed particularly for filtering air for the passenger compartment of motor vehicles.

Abstract: An air purification method for use in an apparatus is provided. The air purification method includes: acquiring plant information associated with one or more plants located in a target detection region; determining, based on the plant information and predetermined reference plant information of an allergy-causing plant, that the target detection region contains the allergy-causing plant and the allergy-causing plant is in a blooming state; and in response to the determining, enabling an air purification function of an air purification device.

Abstract: A filter module configured for exhaust application, and a method and apparatus for testing the same are provided. In one embodiment, the filter module includes a downstream sampling port configured to allow a technician to sample flow, downstream of the filter module, from the cleanroom side of a filter module. In another embodiment, a shroud adapted to sealing engage a filter module under test is provided and includes a tube, disposed in the shroud, that couples a port to a downstream sampling port of the filter module.

Abstract: A highly alkalized humic and fulvic filter reagent for the removal of multiple contaminants from a gas is provided. The contaminants removed from the gas stream may include, but are not limited to, Carbon Dioxide, Sulfur Oxide, Nitrogen Oxides, Hydrogen Sulfides, radionuclides, mercaptans, ammonia, toxic metals, particulates, volatile vapors, and organics. The present invention further includes the disposal of the filter reagent by way of using the highly alkalized humic and fulvic filter for soil fertility, releasing the carbon dioxide from the filter reagent, converting the liquid filter reagent into a solid for disposal or for use as a contaminant removal filter for waters, wastes, and chemicals.

Abstract: Apparatus and method to mitigate the spread of respiratory emission of a sneeze are disclosed. The apparatus includes a spacer component and at least one filtration component. The at least one filtration component is disposed atop the spacer component. The spacer component includes a corrugated sheet, which forms a plurality of directional flutes to direct filtered air out of the apparatus. The least one filtration component filters the respiratory emission to produce the filtered air. In accordance with the method, the respiratory emission is filtered through at least one filtration component to produce filtered air, and the filtered air is directed through a spacer component comprising a corrugated sheet, which forms a plurality of directional flutes that direct the filtered air out of the apparatus.

Abstract: A system and method recover water from an ambient airstream. Dehumidification of the airstream is also achieved by removal of the water. A device of the system includes a chamber having a group of trays that hold respective amounts of liquid desiccant in each tray. A foam media absorbs the desiccant to increase an exposed surface of the desiccant to the airstream. Fans and valves are used to control airflow through the device. A charge cycle circulates air through the device to remove water vapor from the airstream. A subsequent extraction cycle removes water collected in the liquid desiccant by a condenser communicating with the chamber. An integral heat exchanger adds heat to the chamber during the extraction cycle. A controller is used to integrate and manage all system functions and input variables to achieve a high efficiency of operational energy use for water collection.

Abstract: A device for sanitizing objects using ozone is disclosed having a container defining an enclosed space and a selectively closeable opening for enclosing the space, an ozone generator, an ozone converter, a controller, and a timer working together to generate a predetermined concentration of ozone within the enclosed space and maintain approximately the same concentration for a predetermined period of time. Also disclosed are assemblies and methods detecting and warning of entrapment within the enclosure and halting ozone production when it occurs. Further disclosed are devices and methods for coupling a maintenance device to the sanitizing system to perform various maintenance operations such as adjusting operational control parameters, and observing conditions within the enclosed chamber in real-time such as temperature, humidity, and ozone concentration.

Abstract: A process for removing carbon dioxide (CO2) by means of an absorption medium from a cycle gas system, wherein the CO2 occurs within a process in which, in the gas phase, ethylene is oxidized by oxygen (O2) to ethylene oxide (EO) in the presence of a catalyst, in which, as by product, CO2 is generated, by using as absorption medium an aqueous solution of one or more amines, wherein, for further purification of the cycle gas stream obtained downstream of the CO2 absorption step, this cycle gas stream is brought into intimate contact with water to which no mineral acid and no higher glycol was added.

Abstract: A filter assembly for an additive manufacturing apparatus has a housing defining a gas inlet and a gas outlet. A filter element is located within the housing between the gas inlet and the gas outlet. The assembly includes valves that can be actuated to seal the gas inlet and the gas outlet. Additionally the assembly has a fluid inlet for allowing ingress of a fluid into the housing. The assembly allows a filter element, which may contain volatile particles, to be changed safely. By sealing the gas inlet and outlet and flooding the housing with a suitable fluid, volatile particles captured by the filter can be neutralised.

Abstract: In a bubble-column vapor mixture condenser, a fluid source supplies a carrier-gas stream including a condensable fluid in vapor phase. The condensable fluid in liquid form is contained as a bath in a chamber in each stage of the condenser, and the carrier gas is bubbled through the bath to condense the condensable fluid into the bath. Energy from condensation is recovered to a coolant in a conduit that passes through the liquid in the stages of the condenser. The bubble-column vapor mixture condenser can be used, e.g., in a humidification-dehumidification system for purifying a liquid, such as water.

Abstract: A block-base bag is for vacuum cleaners. The bag includes, in the interior thereof, a diffuser made of strips of material and/or sheet materials with oblong-shaped flow openings. Such bags are distinguished by excellent dust storage capacity and extension of the useful life.

Abstract: The airflow controlling device includes a bacteria counting portion counting bacteria of a controlled space; a first smoothing processing portion performing a first smoothing process on the bacteria count; a second smoothing processing portion performing a second smoothing process on the bacteria count; a bacteria reducing capability storing portion storing a bacteria reducing capability relative to each flow rate; a first flow rate evaluating portion selecting a flow rate matching a bacteria reducing capability compatible with an increase in a bacteria count forecasted from the processing result of the first smoothing processing portion; a second flow rate evaluating portion selecting a flow rate matching a bacteria reducing capability compatible with an increase in a bacteria count forecasted from the processing result of the second smoothing processing portion; and a flow rate determining portion selecting a flow rate into the controlled space based on the flow rates selected by the first and second flow r

Abstract: A non-woven textile based filter media is produced from polyester fiber generated using recycled polyethylene terephthalate (PET) beverage bottles, and that non-woven textile based filter media is used to make an air filter. By controlling the diameters and lengths of the PET derived polyester fibers, a non-woven textile based filter media that exhibits a natural Minimum Efficiency Reporting Value (MERV) of about 8 (without requiring electrostatic treatment) and a pressure drop of 2.9 PSI or less can be achieved. A related exemplary embodiment is an air filter fabricated entirely from recycled materials, including a recycled cardboard frame, the non-woven textile based filter media made from recycled PET derived polyester fibers, and a support structure made of recycled plastic or metal wire.

Abstract: A method and an apparatus are provided for deodorizing and disinfecting air and droplets from urinal, toilet bowl, and other receivers and holders of urine and fecal matter. The apparatus comprises a housing (1) having an air inlet (2) and air outlet (3), wherein the housing (1) encloses a droplet removal chamber (4) for removing droplets from airflow; a deodorization and disinfection chamber (5) for removing air contaminants in the airflow; and an delivery unit (6) for airflow generation. Being actively drawn into the apparatus, air contaminants such as odor, bacteria and virus are removed without discharge of contaminated air and causing secondary pollution. The apparatus and method provide odorless and comfortable environment and avoid disease transmission in both public and domestic toilets.

Abstract: A flat bag for vacuum cleaners includes, in the interior thereof, at least two diffusers made of strips of material and/or sheet materials with oblong-shaped flow openings. Such flat bags are distinguished by excellent dust storage capacity and extension of the useful life.

Abstract: A flat bag is for vacuum cleaners. The bad includes, in the interior thereof, at least one diffuser which forms an intermediate plane and is made of strips of material and/or sheet materials with oblong-shaped flow openings. Such flat bags are distinguished by excellent dust storage capacity and extension of the useful life.

Abstract: Vacuum cleaner filters, in particular replaceable vacuum cleaner filters suitable for both dry and wet/dry type vacuum cleaners are disclosed, as well as systems incorporating the use of such filters and methods for their use. The filters include a plurality of adjacently positioned pleats arranged in a closed circumferential, cylindrically-shaped path, a top end cap having a central orifice capable of constricting a post on a vacuum filter cage, and optionally a molded end ring oppositely-spaced from the top end cap for engagement with the motor housing of a vacuum cleaner.

Abstract: A method and an apparatus are provided for deodorizing and disinfecting air and droplets from urinal, toilet bowl, and other receivers and holders of urine and fecal matter. The apparatus comprises a housing (1) having an air inlet (2) and air outlet (3), wherein the housing (1) encloses a droplet removal chamber (4) for removing droplets from airflow; a deodorization and disinfection chamber (5) for removing air contaminants in the airflow; and an delivery unit (6) for airflow generation. Being actively drawn into the apparatus, air contaminants such as odor, bacteria and virus are removed without discharge of contaminated air and causing secondary pollution. The apparatus and method provide odorless and comfortable environment and avoid disease transmission in both public and domestic toilets.

Abstract: An air purifier has a housing with an inlet for receiving air and an outlet for exhausting air. The housing provides an air flow path for the flow of air in a downstream direction, from the inlet towards the outlet. Particulate pre-filtration is located within the housing downstream from the air inlet. VOC pre-filtration is located within the housing downstream from the particulate pre-filtration. UV filtration is located within the housing downstream from the VOC pre-filtration. VOC post-filtration is located within the housing downstream from the UV filtration. Final particulate filtration is located within the housing downstream from the VOC post-filtration.

Abstract: An air purifier has a housing with an inlet for receiving air and an outlet for exhausting air. The housing provides an air flow path for the flow of air in a downstream direction, from the inlet towards the outlet. Particulate pre-filtration is located within the housing downstream from the air inlet. VOC pre-filtration is located within the housing downstream from the particulate pre-filtration. UV filtration is located within the housing downstream from the VOC pre-filtration. VOC post-filtration is located within the housing downstream from the UV filtration. Final particulate filtration is located within the housing downstream from the VOC post-filtration.

Abstract: Disclosed is an air distribution control unit or a filtration/ventilation unit which is portable and/or can be mounted on or integrated in furniture e.g. as a cabinet of at the head region of a bed. The filtration/ventilation unit cleanses air from a person/patient by aspirating the person's/patient's exhalation air into the filtration/ventilation unit. To construct an at least partly isolated area around the patient, filtered air can be directed e.g. vertically out of the filtration/ventilation unit to perform an air curtain. Use of the filtration/ventilation unit reduces the risk of dissipation of air-borne diseases and health hazardous matter, and reduces the amount of air to ventilate a room with patients.

Abstract: A suction nozzle for use in a vacuum cleaner includes a suction opening through which air is drawn in from a surface to be cleaned, a sterilization chamber having at least one inlet and at least one outlet, the sterilization chamber being in fluid communication with the suction opening through the at least one inlet, and a sterilization unit disposed in the sterilization chamber to sterilize the air drawn into the sterilization chamber. The air drawn into the sterilization chamber revolves while moving from the at least one inlet to the at least one outlet.

Abstract: The present invention provides a method and apparatus for removing chemical sterilant molecules from a medium, such as a carrier gas. In one embodiment, the apparatus includes a housing that defines an internal cavity. The housing has an inlet and an outlet fluidly communicating with the internal cavity. An electrode is dimensioned to be received in the internal cavity of the housing. The electrode is made of a material that is chemically active with respect to molecules of a chemical sterilant and conductive to electricity. The electrode is connected to a source of an electrical charge such that an electrical field gradient is formed in a region of space surrounding the electrode. The electrical field gradient is operable to force the chemical sterilant molecule toward the electrode.

Abstract: The present invention discloses an article with an antimicrobial property, and a manufacturing method thereof which gives the antimicrobial property to a surface of the article in which bacteria or viruses may contact to proliferate themselves. The antimicrobial property is obtained by coating Kimchi lactic acid bacteria culture fluid with a wide antibacterial spectrum singly or in combination with nano metal particles on the surface of the article.

Abstract: The invention relates to vacuum cleaner filter bag with a bag wall made of a filter material, wherein the bag wall and/or the interior of the vacuum cleaner filter bag comprise fibres containing a biopolymer and having an antibacterial effect and/or a powder produced from a biopolymer and having an antibacterial effect.

Abstract: A sealed air purifier is disclosed. A housing is formed by connecting a first shell and a second shell. The first shell and the second shell communicate via separable connecting base and connector. A retractable bag encloses the connecting base and the connector. A sealing structure is provided between both ends of the bag. The first shell has an air inlet connecting the inside and the outside and a gate to control the airflow. A compression assembly is disposed in the first shell. The second shell has an air outlet connecting the inside and the outside and a blocking element to control the air outlet. The second shell has a sterilizing device and a super ULPA filter. When the gate closes the air inlet, the compression assembly, sterilizing device, and the air outlet close correspondingly, so that the inside of the housing is isolated. Thus, the viruses remaining therein do not spread with air.

Abstract: An air filter system (10) has a filter housing (11), an air filter media (12), and an electrical circuit (13) electrically coupled to the media. The filter media consists of a pleated air filter material (23) with front pleat apexes (25) and rear pleat apexes (26) which are coated with an electrically conductive material to form front vertical strips (27) and rear strips (28). The electrical circuit includes a positive front electrical contact (30) and a rear electrical contact (31). The front electrical contact has a rear surface (30?) in electrical contact with an elongated front electrical contact bar (33), oriented horizontally across and in electrical contact with the filter front strips of conductive ink. Similarly, the rear electrical contact has a front surface (31?) in electrical contact with an elongated rear electrical contact bar (34), oriented horizontally across and in electrical contact with the rear strips of conductive ink.

Abstract: An air cleaning humidifier which minimizes interference or resistance between cleaned air and a disc assembly mounted to the humidifier to perform the humidifying function while the cleaned air is being passed through the disc assembly by a ventilation fan. The air cleaning humidifier includes a body frame having an air discharge port, a water tub disposed in the body frame, a ventilation fan generating an air current in the body frame, and a disc assembly arranged around the ventilation fan and rotated with a part thereof submerged in the water tub. The disc assembly includes a ring portion forming a circumferential body thereof and a cut portion formed by cutting a part of the ring portion and disposed near the air discharge port.

Abstract: A filter membrane includes a substrate, a polymer layer provided on the substrate and a plurality of filter openings each having a width of from about 2 nanometers to about 5 nanometers provided in the polymer layer. A method of controlling pore size of a filter membrane and a method of decontaminating a filter membrane are also disclosed.

Abstract: An onsite chemistry air filtration system to remove gaseous contaminants from air is disclosed. The onsite chemistry air filtration system of the present invention comprises: a conventional particulate filtration section, a photochemical filtration section, a static gas phase filtration section and a catalytic filtration section. The conventional particulate filtration section captures solids and condensables. In the photochemical filtration section, UV lamps generate bio-destruction and surface photochemical activity on a semiconductor catalyst material, provide a radiation source to irradiate airborne contaminant molecules and to energize their states to promote reactions and generate airborne ozone and radicals. In the static gas phase filtration section, gas phase filtration media is used to capture contaminants, concentrate them in a relatively confined space and allow airborne generated chemistries to concentrate and react in-situ, thereby creating a regeneration effect on the media.

Abstract: A storage compartment comprises an enclosure defining a storage space and an air treatment system in fluid communication with the interior space. The air treatment system includes a light source and a catalyst and configured to treat air without the use of ozone.

Abstract: A sanitizing and cooling apparatus particularly for motor vehicle cabins includes a ventilation and climate control device connected to a plurality of main ducts provided with vents and includes a plurality of flow redirection devices. The particularity of the present invention resides in that it includes an extraction and sanitizing means which is connected to the main ducts and cooperates with the ventilation and air-conditioning device and with the flow redirection devices.

Abstract: A water treatment system comprising a separable water treatment component and a host water treatment apparatus is described. The component is useable in the host apparatus, and has an electronic circuit which is adapted to co-operate with an electronic circuit in the host apparatus. In typical operation, the electronic circuit of the component includes at least a data tag, and the presence of the data tag is identified by the electronic circuit of the host apparatus upon correct fitment and/or installation of the component, which creates a two-way communication protocol. The host apparatus can then upload relevant data from the data tag, etc., and the component's circuit can download the relevant information from the host apparatus. The present invention provides the benefits of electrical co-operation and data tagging.

Abstract: Sterilisation of airflow in a duct may be achieved by irradiating the air with light in the ultraviolet spectrum. Electrodeless bulbs may be enclosed in part of a duct and fed with RF energy in order to energize the bulb. The RF energy may be contained using grids dimensioned to be opaque to the selected RF wavelength.

Abstract: An apparatus for air treatment includes at least one reservoir which can be filled with a liquid, an air-conveying device and a device which ensures that for the treatment of the air to be treated the air comes into contact with at least a part of the liquid. A circulating device is provided, by which liquid in the reservoir is conveyed in a circuit out of the reservoir and back into the latter. For the purpose of sterilising the liquid, a device for mechanico-physical opening of cell membranes, for instance by electroporation or cavitation, is provided in the circuit. Such an apparatus can also be used for purifying exhaust air in a surface treatment installation.

Abstract: A filter assembly for an air purifier is provided. The filter assembly includes base plates that are curved and have a lamp insertion hole formed at its center so that an ultraviolet (UV) lamp can be inserted thereto, a gap retaining member that keeps the base plates spaced apart from each other and combined with each other. Surfaces of the base plates are coated with either a photocatalyst material and silver nanoparticles. According to the filter assembly, the sterilizing and disinfecting capability can be enhanced by increasing a contact area between each of base plates and silver nanoparticles. In addition, since the filter assembly is easily assembled, length adaptability of the filter assembly can be achieved.

Abstract: An integrated and modular infrastructure resource system (IRS) is herein described. The IRS includes one or more infrastructure modules adapted to fulfill a given infrastructure needs such as electrical power, communications, water purification, and air filtration. The IRS may be controlled locally by a control module coupled to the infrastructure modules by a power bus and a control bus or remotely by a remote control-panel that communicates with the IRS by means of a communications module that includes a two-way communications device. The power bus and control bus act to network all of the provided infrastructure modules into an integrated system. Maintenance and logistics for a plurality of IRS's may be managed remotely by a single remote control panel.

Abstract: An antimicrobial purification device for ventilation, heating and/or air conditioning systems diffuses a volatile purification agent. The antimicrobial purification device includes an air filter (1) having a frame (2) holding a filtering agent (3). The filter (1) comprises at least one means for integrating substrate (5) holding the purification agent, consisting of a housing (4) holding the substrate (5) positioned in the frame (2) of the filter (1) or in a container mounted on this frame (2). A cap (6) sealing the housing (4) is fitted with a pin (18) to pierce a protective cover (19) in order to diffuse the purification agent as required.

Abstract: A refrigerated appliance is disclosed. The refrigerated appliance comprises an enclosure defining a cooled space and having an outer wall and an inner wall spaced apart from the outer wall to define an air duct. The refrigerated appliance further includes an evaporator disposed at least partially in the air duct and configured to cool air in the air duct, and the evaporator fan is configured to move air from the air duct into the cooled space, and an air treatment system at least partially located in the air duct. A portion of the air passing through the air duct passes through the air treatment system. The air treatment system comprises a filter cartridge or module, a base with a receptacle configured to receive the filter cartridge, and a mounting or coupling mechanism configured to move the filter cartridge into and out of engagement with the base. The mechanism has a release handle such that both the release handle and the cartridge are accessible from the cooled compartment.

Abstract: The present invention relates to an air cleaning and filtering system, comprising an air intake filtering part and an air outlet filtering part, wherein the air intake filtering part further comprises filtering devices which connect with the air inlet and the air outlet of the air intake filtering part, wherein the air intake filtering part and the air outlet filtering part further comprise sterilizing units. The air cleaning and filtering system of the present invention can provide filtering and sterilization to the incoming and outgoing air of a room to purify and circulate the indoor air and prevent the backflow of the infected air, thus preventing disease spreading through air flow. The air cleaning and filtering system of the present invention can be widely used in hospital, mobile treatment room, clinic, hotel, theatre, office, toilet, public vehicles and home, etc.

Abstract: An onsite chemistry air filtration system to remove gaseous contaminants from air is disclosed. The onsite chemistry air filtration system of the present invention comprises: a conventional particulate filtration section, a photochemical filtration section, a static gas phase filtration section and a catalytic filtration section. The conventional particulate filtration section captures solids and condensables. In the photochemical filtration section, UV lamps generate bio-destruction and surface photochemical activity on a semiconductor catalyst material, provide a radiation source to irradiate airborne contaminant molecules and to energize their states to promote reactions and generate airborne ozone and radicals. In the static gas phase filtration section, gas phase filtration media is used to capture contaminants, concentrate them in a relatively confined space and allow airborne generated chemistries to concentrate and react in-situ, thereby creating a regeneration effect on the media.

Abstract: An air treatment system includes a housing defining a chamber, and an ultraviolet lamp positioned within the chamber. The housing further defines an air inlet at a first end portion of the housing and an air outlet at a second end portion of the housing opposing the first end portion. The chamber provides flow communication between the air inlet and the air outlet. At least one ultraviolet lamp is positioned within the chamber. The at least one ultraviolet lamp is positioned about a first axis and includes a first end and a second end spaced with respect to the first end along the first axis. The at least one ultraviolet lamp is configured for facilitating inactivating contaminants within air channeled through the chamber.

Abstract: Devices and systems are provided, that entrain ambient air within a primary stream of pressurised air, for use in a variety of applications including aircraft, buildings and other stationary structures. The ambient air is drawn through an air treatment such a filter before entrainment within the primary stream. The combined streams are then delivered to a ventilation system, an air curtain or other suitable recipient of treated, thermally conditioned air. The systems include air curtain systems and ventilation systems for aircraft and other vehicles.

Abstract: An air purifier to improve air quality for breathing is disclosed. A magnetized torch module that passes a large air flow is designed. The emission spectroscopy of the torch indicates that the plasma effluent carries an abundance of reactive atomic oxygen (RAO), which can effectively kill all kinds of microbes. The invention employs two torch modules which run alternately to generate non-thermal plasma for air treatment via both thermal/non-thermal processes. The air flow through the on-torch module is mainly treated thermally. A controlling air valve is designed to direct the exiting airflow of the off-torch module to pass through the plasma torch of the on-torch module for non-thermal treatment. The controlling air valve also works to turn the torch modules on and off synchronizing with the closing and opening of the two air valves in the controlling air valve. This device purifies ambient air in a fast rate and kills microbes thoroughly.

Abstract: The apparatus and method provide an airflow to a person or group of persons or a space such as within an airplane cabin or cockpit, operating in conjunction with an air supply which produces a high velocity air stream, such as an aircraft gasper (14). Existing systems may filter, purify and/or clean the air supplied to the occupant, and the air exiting the personal air outlet may be adjusted to a relatively high velocity. The narrow, high velocity stream of air forms a turbulent boundary layer, which tends to entrain potentially foul air from the surrounding region and directs it towards the passenger. The airflow from the apparatus and method may have reduced velocity and lower thermal and humidity gradient and may be treated to remove locally-originating contaminants. The apparatus includes a housing which receives a primary stream of air, such as from an aircraft gasper (14) or personal air outlet.

Abstract: The air clarifying apparatus includes a negative ion generator and an indoor air circulator. It further includes an ozone generator having a capability of maintaining the average concentration value of ozone in an indoor atmosphere at 0.02 to 0.05 ppm, while the average concentration value of negative ions in the vicinity of the blowout port of the negative ion generator is maintained at 200,000 to 1,000,000 pieces/cc. With this configuration, the negative ions coexist with ozone having a low concentration.

Abstract: An interfloor noise reduction panel with an air purifying function for buildings is capable of reducing impact due to the dropping of a weight and electromotive forces of machinery as well as noise and vibration transmitted through the floor of the building through the structure in which a plurality of springs, a sound-absorbing material, an ion mortar layer are disposed in a base panel such that noise generated by pressure applied to the panel above is absorbed and thus maximally extinguished.

Abstract: In a particular embodiment, an air purifier assembly is disclosed and can include a housing assembly. The air purifier assembly can include a first fluid communication channel within the housing assembly. The first fluid communication channel can have an air inlet formed in a back of the housing assembly and an air outlet formed in a first side of the housing assembly. Further, the air purifier assembly can include a second fluid communication channel within the housing assembly. The second fluid communication channel can have an air inlet formed in a back of the housing assembly and an air outlet formed in a second side of the housing assembly, opposite the first side of the housing.

Abstract: Ultraviolet radiation is used to disinfect air (105) in a flow tube (110), where the flow tube (110) includes total internal reflecting features (120) on a portion of its external surface and said ultraviolet radiation propagates through a portion of the flow tube via total internal reflection.