An apparatus (10), including a gas recirculation circuit comprising a mini environment chamber (14), a gas pump (16), a filter assembly (22) which are connected by a recirculation channel (20). The apparatus additionally includes an air supply conduit (18) for supplying air to the gas recirculation circuit and having an air supply conduit inlet (18a) which opens into the ambient air and an air supply conduit outlet (18b) which opens in the recirculation circuit. In use, a mini environment chamber pressure (P.sub.me) is maintained higher than the ambient pressure (P.sub.am). The gas recirculation channel (20) includes a substantially frictionless recirculation restriction embodied as a throat (30). At downstream end of the throat which forms the narrow part of the throat, in use, the static pressure is below the ambient pressure. The air supply conduit outlet opens at the downstream end (30a) of the throat.

Improvements in an outside house vent that blocks embers, water and rain that can cause damage to a house of building. The prevention of fire and ember intrusion into a building prevents fires in homes where invalids and children are left alone. The prevention of water into structure further reduces the potential for mold growth in the attic or walls of a home or structure. The filtering further prevents intrusion of creatures such as but not limited to bugs, insects, bees, wasps, animals, critters and other flying and crawling animals from entering the building. The vent is a fireproof set of louver or filter pads with fire arresting screens that is passed through a wall that vents into the building. The vent can be installed on old and new construction to provide improved fire prevention, increase the value and salability in fire prone areas.

Contaminants present in air ducts or other components of HVAC systems may be carried by moving air passing through the HVAC system and ultimately delivered as air contaminants to rooms in which such contaminated air may be breathed in by humans. An air filter system is described for removing air contaminants from moving air passing through a register or grille between an air duct of a HVAC system and a room. The air filter system includes one or more air filters within an interface housing or secured by a frame that is attached or adhered to the register or grille so that the air filter removes at least some of the air contaminants in the moving air passing from the air duct through the register or grille before it enters the room. Methods for assembling and manufacturing air filter systems are also described.

A venting system includes a frame and a register cover attached to the frame. The register cover includes a plurality of alternating open areas and air diverting fins vertically orientated on the register cover. Three open areas among the plurality of open areas are disposed proximate a central portion of the register cover. A tool engagement feature is located at the central portion of the register cover and includes a plurality of concave surfaces formed on at least four of the air diverting fins among the plurality of air diverting fins. The tool engagement feature further includes a forwardly projecting knuckle arranged at a center of each of the three open areas disposed at the central portion of the register cover.

The present invention relates to an air filter housing for supplying air to a space, said air filter housing being configured to be arranged in a ceiling of said space, said housing having a mouth facing downward, said mouth comprising a sealing surface configured to receive a panel type air filter comprising a frame and a filter medium held within said frame, such that a sealing connection between said sealing surface and said frame is achieved, characterized in that said filter housing further comprises at least one resilient member arranged below the sealing surface such that when a panel type air filter is inserted into the mouth, the resilient member will be deformed by the filter frame as the filter passes the resilient member, and resume its original shape once the filter has passed, such that the filter is retained between the sealing surface and the resilient member. The present invention further relates to the use of a filter housing in a cleanroom, and to a method of mounting a panel type air filter in an air filter housing.

A frame assembly for an air distribution system includes a damper assembly, a louver assembly, and a screen frame. Air flows through the damper assembly and the louver assembly, where the damper assembly terminates in a first flange and the louver terminates in a second flange. The first flange and the second flange are coupled to one another about a screen frame such that the screen frame is captured by abutting the first flange and the second flange.

A ventilation device 21 configured to be connected to a mouth of a ventilation duct 9 between the ventilation duct and an outside space. The ventilation device comprises an airflow opening 27 for passage of an airflow 30 between the ventilation device and the outside space. An air-permeable material 29 is arranged in the airflow opening 27.

Examples of the present disclosure are related to systems and methods for replaceable multiple filter units. More specifically, embodiments describe replaceable filter units that are configured to simultaneously filter fresh and return air.

The present disclosure envisages an air grille. The air grille comprises a front face and a duct face end. The duct face end is in the opposite of the front face. A plurality of flaps are configured on the duct face end, wherein the flaps are capable of collapsing. During shipping the flaps are collapsed whereas before installation the flaps are uncollapsed to facilitate containment of an air filter. The air grille has first thickness when the flaps are collapsed and second thickness when the flaps are uncollapsed, wherein the first thickness is less than the second thickness.

In-situ calibration of a flow measurement device in a forced air HVAC system. A flow measurement that is obtained by a flow measurement device that is temporarily installed in the HVAC system is used to calibrate a flow measurement device that is permanently installed in the HVAC system. The calibration described herein can be aided by a technician installing or servicing the HVAC system.