Abstract: In a system for the adaptive camouflage of objects, particularly of vehicles, at least one panel-like layer (5) is provided, which is at least partially air-permeable. The air suctioned in from the surroundings can be controlled, before or while it is fed into the layer, to a temperature that is determined at least almost from the background of the object.

Abstract: Techniques described herein are generally related to a biofilter for living spaces. The biofilter may include an organic biofilter medium to serve as a growth base for both plants and one or more microbial colonies. Example embodiments include systems, articles, methods and apparatus, as well as other embodiments that are described and claimed.

Abstract: A ceiling-mounted air conditioner is provided.

Abstract: A ventilation inlet comprising a ventilation pipe to receive flow from a first flow zone and to deliver the flow to a second flow zone; a divider arranged to divide a portion of the ventilation pipe into a static pressure zone and a total pressure zone; and a deflector arranged to direct flow from the total pressure zone at least partially across the static pressure zone to restrict delivery of the flow from the static pressure zone to the second flow zone dependent on the pressure of the flow in the first flow zone.

Abstract: Openings 1a and 1a releasing, to the outside, positive and negative ions generated respectively by positive and negative ion generating parts 2 and 3 are formed in different inclined surfaces of a case (an air guiding member) 1 having a regular quadrangular pyramid shape. The positive and the negative ions are released in different directions, and hence recombination of the ions is suppressed. The case 1 guides the air to the openings 1a and 1a from which positive and negative ions are released respectively. The positive and the negative ions released into the guided air flow together with the air flowing, for example, in different directions K3c and K3d. This suppresses recombination of the ions and enhances diffusion of the ions.

Abstract: The invention relates to an induction unit for uniting air flows, comprising at least one induction duct (21) coordinated with a primary air duct (30) and having an upstream end and a downstream end and a straight reference line (A) passing through the ends, and at least one first opening (28) for a primary air flow (F1), connected to the primary air duct (30) and opening with concurrent flow into the induction duct (21). The induction duct (21) has a secondary air intake (22) for the intake of a secondary air flow (F2) from a space surrounding the induction unit and an outlet (24) designed to return an air flow (F3) resulting from the primary air flow and the secondary air flow to the space surrounding the induction unit. The secondary air intake (22) is arranged at the upstream end of the induction duct (21) and is directed substantially parallel to the center line (A) thereof.

Abstract: The present invention relates to an air intake grid (11) having a mesh (12) provided with elongate elements (16), two adjacent elongate elements (16) crossing at a node (14, 15). At least one elongate element (16) is surrounded by at least one anti-icing member (20), said anti-icing member (20) having a downstream portion (22) matching the shape of said corresponding elongate element (16) and an elongate upstream portion (21) that is resilient and that vibrates under the effect of vortices generated by a flow of air (30) passing through said grid (11) after ice has become deposited (31) on said upstream portion (21).

Abstract: The present invention provides a system and method for manually balancing the volume of air supplied through at least one duct to a conditioned space the system including a damper rotatably mounted within the air duct by a damper shaft having a first and second ends, an electronic pulse actuator responsive to an electronic pulse being associated with the first end, a housing associated with the electronic pulse actuator is generally adapted for operably connecting the electronic pulse actuator to the air duct and a remote positioning unit in electric communication with the electronic pulse actuator where the damper is rotated between an open and a closed position for manually balancing the conditioned space to receive the desired volume of air.

Abstract: The device (8) comprises a casing (10) defining an inner chamber (11) and having an inlet orifice (14) for fresh ventilation air (12), an inlet orifice (15) for recycled air (16), and blowing orifices (19) for blowing out air contained in the inner chamber, which are intended each to be connected to a reception room of the premises. Units (25) for heat-treating the air are each combined with a blowing orifice and are controlled independently of one another according to the setpoint temperature of the corresponding reception room. The method consists in feeding recycled air into the inner chamber only if that is necessary to achieve the setpoint temperature in a reception room, and in heat-treating the fresh ventilation air, and if appropriate the recycled air, independently room by room.

Abstract: An antimicrobial fabric and method for treating fabric to impart antimicrobial properties thereto by preparing an aqueous solution of eugenol, polyvinyl alcohol, and glyoxal, padding the fabric with the aqueous solution to achieve a preselected desired part by weight wet pickup, drying the fabric; and curing the fabric.

Abstract: An arrangement for measuring air flow includes a source of measurement values and a processing unit. The source of measurement values is operable to generate measurement values representative of a difference in pressure from air obtained on a first side of an obstruction and air obtained on a second side of the obstruction. The processing unit is configured to, in one case, convert any negative measurement values of the measurement values to a less negative value. The processing unit is further configured to perform low pass filtering on the measurement values and convert the filtered measurement values to a flow value.

Abstract: Various aspects provide for ventilating a circular building, including an external wall of the building in the shape of a circular polygon, a plurality of vertical wall sections each forming a side of the polygon, each vertical wall section secured to an adjacent vertical wall section at a vertex of the polygon and a metallic frame for supporting the vertical wall section. A glass skin may be secured to the metallic frame of the vertical wall section, the glass skin including an exterior opening and a vent chamber configured for receiving air from the exterior of the building through the exterior opening in the glass skin. The vent chamber may include an interior opening for communicating air from the chamber into the interior of the building and a movable flap for controlling a flow of air through the vent chamber.

Abstract: Air treatment modules, systems and methods for removing contaminants from indoor air are provided. Device embodiments may include one or more air inlets, one or more air outlets and a plurality of inserts which each include at least one adsorbent material. The inserts may be arranged separate from each other to form a plurality of substantially parallel air flow paths between the one or more air inlets and one or more air outlets. The adsorbent material may be arranged for regeneration within the air treatment module using thermal swing desorption and/or pressure swing desorption. Related systems, methods and articles of manufacture are also described.

Abstract: A high-rise building has a stairwell, an air supply shaft, inlet openings connecting the air supply shaft to the stairwell, and a pressure system for keeping the stairwell free from smoke. The stairwell is vertically divided into several partial spaces. The separation is performed by at least one partition. Each partition has a door enabling a passage from one partial space of the stairwell into an adjacent partial space.

Abstract: A device for a supply air ceiling of the laminar flow type, a so-called LAF ceiling, which is zoned and where the individual zones are adapted to be supplied with cleaned air with controllable temperature, humidity and volume per time unit. At least one of the clean air zones is adapted to cooperate with or be constituted wholly or partly by a nozzle-equipped unit which is separately supplied with clean air with controllable temperature, humidity and velocity, and where the air velocity out of the nozzle(s) in the unit is higher than the air velocity out of said at least one zone or zones adjacent to the unit. Upstream of the nozzle part of the unit there is arranged a clean air filter and the area of the clean air filter is greater than the cross-section of the said nozzle part.

Abstract: A vent apparatus (10) comprises a perforated screen (12), a door (18), a guide (24), and a handle (26), and a lever assembly (30). The door is adjacent a first face (13) of the screen and includes at least one arm (20, 22) that extends through at least one slot in the screen. The guide (24) is mounted adjacent a second face (14) of the screen. The handle (26) is in pivoting connection with the at least one arm and is operative to move relative to the guide to cause the door to move between a closed position (62) to an open position (64). A lever assembly (30) extends from the handle in pivoting connection with the guide. As the handle moves, the lever assembly is adapted to maintain the handle sufficiently close to the guide such that at least a portion of the handle is operative to slide along the guide.

Abstract: Embodiments of a flow control system and method are disclosed. An exemplary method may include causing air to move along an air flow path through at least one inlet formed in the housing over at least a portion of an electronic device, causing the air to move adjacent one or more component of the electronic device, and causing the air to move through at least one outlet formed in the housing. The method may also include adjusting at least one baffle in the air flow path between different positions based on configuration and power requirements of the electronic device to control the air flow through the housing along the air flow path.

Abstract: A one piece, nestable, portable mini-greenhouse and plant protector for use in a substrate, such as soil, to protect plants and seedlings from extreme weather elements, bugs and pests. The mini-greenhouse has a light-transmitting shell that forms a protective chamber and integrated legs that act to anchor as well as support the shell. The legs can be fully or partially inserted in the soil providing options for a closed or ventilated protective chamber. The unit has concave channels that facilitate watering without disturbing the apparatus. It has unique light filtering and dispersing properties to aid creating a nurturing and growing environment.

Abstract: An aircraft chaff dispenser includes an elongated hollow housing intended to be fixed to the structure of the aircraft so as to be oriented in the longitudinal direction of the aircraft. The housing has a pair of side walls and the front of each side wall is provided with a pair of lateral air intakes each having a circular through-hole with a diameter d and a fence located behind the hole in the longitudinal direction, or in the direction of travel, of the aircraft at a distance 1 from the center of the hole and having a shape in the form of a horizontally lying V with its vertex directed away from the hole. The diameter d of the hole is between 8 and 12 mm. The ratio h/1 between the height h of the fence at the vertex of the V and the distance 1 is between 0.8 and 1, while the ratio h/d between the height h and the diameter d is between 1.5 and 2.

Abstract: A mobile boarding bridge (101) is equipped with climate control facilities. The mobile boarding bridge is furnished with multiple collapsible tunnels (110, 120). A heating/cooling device (160) comprising a climate controller (161) generates hot or cold air and is furnished on the outside of the first tunnel (110) of said tunnels. A connection pipe (163) that connects to ducts (164) within the tunnel is attached to said climate controller (161). A duct (164) connected to said connection pipe (163) directs air that has been heated/cooled by the heating-cooling device (160) to the interior of the first tunnel (110). An aspirator comprises an air intake (171) which intakes air from the interior of the tunnel and an intake pipe (172) which leads air taken in at said air intake (171) to the interior of the climate controller (161).

Abstract: A covering apparatus for an enclosure presenting a ventilating barrier curved with respect to a barrier axis includes a segmented panel member having a plurality of louvered areas. Respective adjacent louvered areas of the plurality of louvered areas are separated by a respective bend structure. Each respective bend structure has a first section departing in a first direction from a first bend axis and a second section departing in a second direction from a second bend axis. The first and second bend axes are generally parallel with the barrier axis. The first direction is generally away from the second bend axis. The second direction is generally away from the first bend axis. The bend structure further has a third section extending from the first and second bend axes to a third bend axis. The third bend axis is non-coplanar with the first and second bend axes.

Abstract: The invention relates to a solar air heater comprising—at least one transparent or translucent front panel comprising at least one first flow passage, said first flow passage substantially elongated and extending along the surface of the front panel,—a back panel preferably substantially parallel with the front panel,—at least one heat absorbing element, preferably located between the front panel and the back panel,—at least one air inlet,—at least one air outlet,—at least a second flow passage between the front panel and the heat absorption element, and—at least a third flow passage between the heat absorption element and the back panel, whereby air flowing through the solar air heater from an air inlet to an air outlet will pass at least a first, a second and a third flow passage.

Abstract: A building (20) has an atrium (24) and an elevator hoistway (40). To mitigate a stack effect in the atrium, a fan (62) may provide a downward airflow (60) through the hoistway.

Abstract: A safety cabinet has a body adapted to contain hazardous substances and having an upright front side, a base underneath the cabinet and adapted to support the cabinet spaced above an underlying floor. The base having an upright front wall below the body, set back from the front side thereof, and formed with a plurality of air intake openings, and structure in the base forming a suction-vent passage extending from the intake openings.

Abstract: An air handling system with an air intake device is provided. The air intake device includes first and second air/water separators having a baffle device positioned between the two separators to redirect the air flow from the first separator so that it is flowing generally longitudinally of the air intake device flow passage. A heater is provided to heat flowing air and snow for collection on a second separator having a foraminous device for subsequent collection and drainage from the air intake device.

Abstract: A solar heating system for a building and other architectural structures including a solar heating system. The solar heating system comprises a solar heating module with an enclosure of panels bounding a plenum. An interior panel is disposed inside the enclosure. A collector panel, which is separated from the interior panel to define a heating chamber, is exposed to, and heated by, solar radiation. Outside air enters the heating chamber though passages in the collector panel, where the air is heated by heat transferred from the collector panel. An air-moving device is coupled with an air outlet from the plenum. The air-moving device applies a negative pressure in the heating chamber effective for drawing the outside air through the passages into the heating chamber and for withdrawing the heated air from the heating chamber through a delivery opening to the plenum for subsequent removal through the air outlet.

Abstract: Provided are methods and devices for improving microvascular function in humans and mammals. Reduction of exposure to airbourne fine particles using air treatment systems increases microvascular function in persons at cardiovascular risk. Preferred treatment systems provide a zone of clean air having >75% reduction in airbourne particle counts around a person at cardiovascular risk. The devices and methods can be optimally used during sleep, when the user is stationary for an extended period.

Abstract: A SDHV damper assembly and methods to assemble and install the SDHV damper assembly are disclosed. The SDHV damper assembly includes a first damper housing half comprising a substantially cylindrical tube having a first open end and a second open end. The SDHV damper assembly further includes a second damper housing half comprising a substantially cylindrical tube having a first open end and a second open end. The first open end of the second damper housing half is joined to the first open end of the first damper housing half to form an assembled damper housing. A recess is formed in the damper housing either diametrically or longitudinally. The expandable damper member is received within the recess and expands to restrict flow in the damper housing and retracts to allow laminar flow through the damper housing.

Abstract: A structure for supporting an air guide vane in a supply opening for air conditioning prevents abrupt changes of load resistance to rotation of the air guide van and provides a good operational feel when rotating the air guide vane. A supporting member of the air guide vane is an olefin-based thermoplastic elastomer having a hardness of between Shore A80 and Shore D60. The degree of mold transferability of olefin-based thermoplastic elastomer is characteristically lower than that of other thermoplastic elastomers. By virtue of molding an olefin-based thermoplastic elastomer microscopic concavities and convexities are formed on the surface of the supporting member. The rotation shaft of the air guide vane is supported by multiple point contacts with the inner surface respective through-holes.

Abstract: A ventilation member and a ventilation member kit are provided that can extend the time until fogging will be produced in a housing and also can shorten the time until the produced fogging will be cleared up even when the interior of the housing has been fogged. A vented housing and a vented tank using them are also provided. A ventilation member includes: a first gas permeable membrane, a second gas permeable membrane, and an absorbing layer allowing a gas passing through an opening of a housing or a tank to permeate therethrough, with the ventilation member being fixed to the opening; a support body for supporting the first gas permeable membrane, the second gas permeable membrane, and the absorbing layer; and a first one-way valve disposed so as to cover the first gas permeable membrane. The first gas permeable membrane and the second gas permeable membrane are disposed in such a manner that the gas permeates through the gas permeable membranes independently of each other.

Abstract: A ventilation device comprises a body (11) having first and second ports (14, 15) and a ventilation passage (13) that extends through the body between the ports to allow airflow through the body. The ventilation device also comprises a noise attenuation device (21) arranged to attenuate noise transmission through the passage in at least one direction from the first to the second port. The noise attenuation device comprises at least one array (22, 23) of noise attenuation tubes disposed in the ventilation body. In one form, the noise attenuation device (21) include two arrays of attenuator tubes disposed on respective opposite sides of the passage (13). The tubes each have a mouth (27) that opens to the passage and a central axis that extends from the mouth in the direction of elongation of that tube.

Abstract: A ventilating exhaust fan housing substantially is a two-piece construction formed from a first structural member and a second structural member. The housing has six sides surrounding and defining an interior space of the housing. The six sides include five sides defined by walls of the housing, and a sixth open side acting as a fluid inlet. The first structural member substantially defines the walls of four sides of the housing, and one of the walls of the four sides defines a fluid outlet penetrating therethrough. The second structural member substantially defines the wall of fifth side of the housing. Therefore, the first structural member and the second structural member cooperatively form a compact ventilating exhaust fan housing.

Abstract: A heat dissipation module including a supporting frame, a driver, a linkage, a first magnet and a plurality of magnetic blades is provided. The supporting frame has a chute. Moreover, one end of the linkage has a protrusion passing through the chute. The other end of the linkage is connected to the driver. The first magnet is disposed on the protrusion. In addition, the repelling magnetic blades are pivoted on the supporting frame. The outermost magnetic blade faces the first magnet and they repel each other.

Abstract: A complete plastic HVAC system assembled using individual plastic components for ensuring the efficient and quiet distribution of air from a central air unit to multiple distribution points and preventing heating and cooling losses, the need for installers to stock multiple sized and shaped components, the accumulation of dust, dirt and pollens during storing, installing and use on the surfaces of the individual components. The fittings have a collar sizable to fit both 6 and 7-inch pipe, whether flexible or rigid. The use of plastic fittings, duct and pipe removes the potential of injury commonly associated with conventional metal ductwork, while providing seamless components that can be configured for any type of installation and insure an air tight connection between adjoining surfaces. The individual fittings include a register boot, torpedo boot, straight boot, rigid and flexible pipe and couplers, straight and 90-degree takeoffs, a plastic duct and duct end cap.

Abstract: A solar heating system for a building and other architectural structures including a solar heating system. The solar heating system comprises a solar heating module with an enclosure of panels bounding a plenum. An interior panel is disposed inside the enclosure. A collector panel, which is separated from the interior panel to define a heating chamber, is exposed to, and heated by, solar radiation. Outside air enters the heating chamber though passages in the collector panel, where the air is heated by heat transferred from the collector panel. An air-moving device is coupled with an air outlet from the plenum. The air-moving device applies a negative pressure in the heating chamber effective for drawing the outside air through the passages into the heating chamber and for withdrawing the heated air from the heating chamber through a delivery opening to the plenum for subsequent removal through the air outlet.

Abstract: An elevator system (20) includes at least one vertical shaft (32) extending between at least two levels (24, 36) of a building (22). One of the levels (24) includes at least one passageway (28) between an interior of the building and the outside environment. At least one second shaft (40) extends between the other building level (36) and at least one other level within the building. The interior of the second shaft (40) is isolated from airflow on the building level (24) that includes the passageway (28) to the outside environment. Disclosed examples include enclosures (52) for isolating the first shaft (32) from airflow on at least one of the levels to which the first shaft provides access.

Abstract: A flotage trapping device comprises at least one plus electrode and at least one minus electrode. The plus electrode and minus electrode are alternately disposed. The electrodes trap the flotage floating in the air. Another flotage trapping device comprises at least one electrode of a single polarity and a space ion generating device for generating ions of polarity opposite to that of the electrode so as to form an ion space around or adjacent said electrode. A flotage repelling device comprises at least one electrode of a single polarity, and a space ion generating device for generating ions of the same polarity as that of the electrode so as to form an ion space around or adjacent of the electrode.

Abstract: A security housing contains a housing body having ventilation openings for supplying air to a heat source, in which air convection takes place for dissipating heat. First air guide elements are disposed in the housing body on a first side of each of the ventilation openings and are shaped for partly covering the ventilation openings. The first air guide elements each have a base integrally molded on the housing body, the bases are spaced apart from each other such that, in each case one of the ventilation openings is further defined. A removable security housing part is disposed inside the housing body and forms an air guide duct. Second air guide elements are disposed in the air guide duct and are shaped such that they cover the ventilation openings and the first guide elements such that, non-rectilinear air guidance is ensured.

Abstract: An HVAC duct sealing system has an air duct wall, a sealing surface, such as an HVAC case, against which the air duct wall is biased, and a seal member interposed between the duct wall and the sealing surface. The seal member is interposed between the air duct wall and the sealing surface and is molded directly onto the air duct wall using a two-shot or double shot method of forming. The seal can be rubber or any flexible, pliable material capable of creating a seal with a surface. The seal has a seal base that is attached to and surrounds an end part and two sides of the air duct wall. The seal has a flexible tip portion extending from the seal base that is biased against and bends against the sealing surface in accordance with an amount of pressing force to create a seal. The flexible tip bends between 0 and 100 degrees from its pre-installation position.

Abstract: A device comprising a rotor and fan rotatably mounted on a shaft which is rigidly fixed relative to a vehicle surface. The device is fixable on a vehicle surface by means of two clamping portions which are moveable towards each other along the shaft to press against a surface between them.

Abstract: An apparatus for accurately sensing room conditions and positioned in the air stream to the return air plenum. The apparatus is a combination of a temperature and volatile organic compound (VOC) sensor. The sensor module is built into a ceiling grid system with the body of the sensor module extending into the return air plenum. The ceiling grid has a slot fabricated into its face which allows the air stream from the room to flow by the sensors on its way to the plenum. This enables both the temperature and the composition of the air to be monitored at the optimal location. A portable pollution sensor device that measures and monitors leading indicators of indoor air quality and the extent of pollution is used in conjunction with the ceiling grid mounted sensor modules. The portable device documents and benchmarks air quality both in buildings under construction and in existing buildings. The portable device is network-enabled so as to simultaneously transmit the data to various control devices.

Abstract: A guard device for an externally mounted vehicle refrigeration unit is provided, comprising an open frame assembly constructed from steel tubing, and having a mounting base, wherein the mounting base includes at least two rigid members adapted to connect to a vehicle body. The guard device includes a front airflow portion, a top access port, and a bottom access port. A front airflow panel is connected to and covers the front airflow portion. A pair of side access ports are also provided within the frame assembly, wherein each side access port is adjacent to the front airflow portion. The side access ports are each covered by reinforced side access panels.

Abstract: Pentapost type air handling unit casing comprising panels arranged side by side and perpendicularly, and side profiles embodied between the perpendicular panels and middle profiles embodied between side by side panels whereby side profiles (2) comprises at least two joined partitions having a predetermined height and width difference with respect to cross-sections thereof and the middle profiles (3) having the same thickness with the side panels are provided with steps on two opposite directions around circumference of the middle profiles (3) and self-drilling screws located inside of plastic bushings (10) for connection of the panels and side, middle profiles and gasket (19) means for air leakage between casing and surroundings thereof.

Abstract: A hidden ventilating sill plate is fundamentally a new building product, installed along the top surface of the exterior perimeter foundation. It replaces the existing wood sill plate. The invention has a continuous set of air slot channels of a proscribed size perpendicular to the longitudinal axis, along its base, communicating natural air flow from the exterior to the interior of the crawlspace. The exterior side of the slot channels can open earthwards to allow the venting to be completely hidden from view, when the sill member extends out beyond the exterior face of the foundation and wall. The vent concealment feature also functions as a base to the siding and an integral drip edge. Insect mitigation is achieve by adding a mesh screen over the exterior exposed slotted openings. The preferred material for this invention is a plastic-fiber composite, allowing rot resistance, shear capabilities and, rapid extrusion or molding of the sill profile.

Abstract: A ventilation member having: a breathable film transmitting gas passing through an opening portion of a housing in a state in which the breathable film is fixed to the opening portion; and a support including a supporting portion for supporting the breathable film and an insertion portion to be inserted into the opening portion of the housing; wherein the insertion portion has a lock portion in an insertion-start-side end portion thereof, the lock portion having a tapered forward end, while the insertion portion is divided into a plurality of parts circumferentially at least on an insertion start side thereof.

Abstract: A snow removal device for use with an air handler or HVAC system includes an extractor plate and a heater for heating the extractor plate. The extractor plate has a plurality of holes and may be bent to define a series of connected “Vs”. The heater may be a heater core, which may be coupled with a snow sensor. Air deflectors may be provided to deflect incoming air towards the hottest part(s) of the extractor plate. The holes in the extractor plate should be sized such that it does not act as a filter. If the heater is a heater core, it may be coupled with the extractor plate using bent metal retainers.

Abstract: A ventilation duct and methods of ventilation are disclosed. The ventilation duct provides a plurality of inner and outer sound absorbing members. The inner and outer sound absorbing members lying in separate planes with portions of the inner and outer sound absorbing members overlapping one another to inhibit the transmission of sound through the duct. The inner and outer sound absorbing members each including a longitudinal cavity filled with a sound absorbing material and having a plurality of sound transmission passages extending through the members to expose the sound absorbing material to incoming sound waves. In addition, the members may be shaped to have a reverse megaphone effect to further reduce the sound transmitted across the duct.

Abstract: The present invention relates primarily to the provision of a Sound Proof Chamber (10), and optionally also relates to an Electronic Surveillance Bug Proof Chamber. Both embodiments comprise a sealed cavity located within all walls, roof, and optionally the floor surfaces of said chamber, which cavity is kept under a Partial Vacuum. The type of chamber which is fabricated is dependent on its intended use. For example, in high level applications, an additional combination of absorbing acoustic, and radio frequency blocking surfacing, and electronic sounds detector can be used to further restrict or detect the transmission of sounds within said enclosure. In lower level applications, the vacuum cavity may have sufficient noise suppression capability. The chamber is of the present invention is preferably manufactured using modular components in an assembly kit form in order to provide the consumer with a variety of chamber shapes, colors and incremental sizes.

Abstract: A ventilation device for electrical control devices is provided in a housing wall of a housing. The ventilation device includes a wall with an inner opening that is open with respect to the space inside the housing and is intended for receiving and delivering a gas from and to the space inside the housing. The wall of the device also includes an outer duct opening that is open with respect to the housing surroundings and is intended for receiving and delivering a gas from and to the housing surroundings. The inner opening and the outer duct opening are connected to each other for leading the gas between the openings through a ventilation duct unit in which a membrane unit is disposed. The inner opening and the outer duct opening are offset laterally with respect to each other such that they do not overlap each other.

Abstract: A ventilation duct and methods of ventilation are disclosed. The ventilation duct provides a plurality of inner and outer sound absorbing members. The inner and outer sound absorbing members lying in separate planes with portions of the inner and outer sound absorbing members overlapping one another to inhibit the transmission of sound through the duct. The inner and outer sound absorbing members each including a longitudinal cavity filled with a sound absorbing material and having a plurality of sound transmission passages extending through the members to expose the sound absorbing material to incoming sound waves. In addition, the members may be shaped to have a reverse megaphone effect to further reduce the sound transmitted across the duct.