The present disclosure relates to air filters. More particularly, it relates to air filters including pleated filter media that can be uniformly expanded and contracted. In some embodiments, the air filters are adjustably sized air filter systems. In some embodiments, the air filters can be used in a window opening.

Apparatus allowing ventilation through a ventilation shaft to an underground ventilation duct fluidly communicating through the ventilation shaft to an atmospheric opening of the shaft and on threat of flooding operable to prevent downward flow of surface water into the underground ventilation duct includes support sidewalls fitting in the shaft providing a ventilation passage between support top and bottom openings and a suspension member supported on opposed lateral sidewalls unobstructively horizontally spanning the passage proximate the top opening and holding one or more hinge connected panels in the passage that manually release to rotationally close the passage and prevent flooding and are manually rotationally liftable to a home position allowing ventilation. The suspension member is liftingly removable from the support and may include end keys received in keyed supports to allow the suspension member to fit in the supports so a specific panel closes to a specific sidewall.

An assembly type ventilation device for windows and doors is disclosed. The assembly type ventilation device for windows and doors comprises: a filter frame provided with an insertion part into which an air filter module is detachably inserted and fixed; a first fixing part installed on one side of the filter frame and fixed to a window; and a second fixing part installed on the other side of the filter frame and fixed to a window frame.

Hollow core door apparatus for preventing the build up of pressure in a room having a register through which air flows into the room and the door includes an inside door skin and an outside door skin, and the door skins includes openings through which air flows and a center panel between the skins and spaced part from the skins. The center panel has an outer perimeter greater than the inner perimeter of the openings. The center panel is spaced apart from the skins, and also from the adjacent stiles and rails. A chamber is formed about the panel and between the adjacent stiles and rails and the openings in the skins. Air flow from the room is through the opening in the inside skin into the chamber, around the outer periphery of the panel, and outwardly through the opening in the outside skin in a non-linear manner.

Hollow core door apparatus for preventing the build up of pressure in a room having a register through which air flows into the room and the door includes an inside door skin and an outside door skin, and the door skins includes openings through which air flows and a center panel between the skins and spaced part from the skins. The center panel has an outer perimeter greater than the inner perimeter of the openings. The center panel is spaced apart from the skins, and also from the adjacent stiles and rails. A chamber is formed about the panel and between the adjacent stiles and rails and the openings in the skins. Air flow from the room is through the opening in the inside skin into the chamber, around the outer periphery of the panel, and outwardly through the opening in the outside skin in a non-linear manner.

The invention relates to an air purification apparatus. The apparatus is disposed in a window for separating an indoor space and an outdoor space. The apparatus comprising: an inlet chamber having a first inlet, a second inlet and an outlet, wherein the first inlet is operatively open to the outdoor space and the second inlet is operatively open to the indoor space; an air pumping unit for pumping air from the inlet chamber to the indoor space through the outlet, wherein the air is pumped into the inlet chamber through the first inlet or through the second inlet; and a filtering unit disposed upstream of the air pumping unit, for filtering pollutants in the air.

The invention relates to an air purification apparatus. The apparatus is disposed in a window for separating an indoor space and an outdoor space. The apparatus comprising: an inlet chamber having a first inlet, a second inlet and an outlet, wherein the first inlet is operatively open to the outdoor space and the second inlet is operatively open to the indoor space; an air pumping unit for pumping air from the inlet chamber to the indoor space through the outlet, wherein the air is pumped into the inlet chamber through the first inlet or through the second inlet; and a filtering unit disposed upstream of the air pumping unit, for filtering pollutants in the air.

A window vent stop for use in a sliding sash window assembly or a sliding door assembly. The vent stop has a housing adapted to be disposed in a recess in the non-movable sash member. This housing includes a cavity with a bottom plate therein. The tumbler has at least one pivot for pivotally securing the tumbler to the housing for movement between an extended position to prevent movement of the sliding member and a retracted position, to allow movement of the sliding member. Also within the housing is a spring for biasing the tumbler. The housing has one or more flexible members extending from the end walls of the housing that secure the housing to an opening in a window sash when a portion of the window sash is positioned between the underside of a lip on said housing and the flexible member.

The present disclosure relates to air filters. More particularly, it relates to air filters including pleated filter media that can be uniformly expanded and contracted. In some embodiments, the air filters are adjustably sized air filter systems. In some embodiments, the air filters can be used in a window opening.

The present disclosure relates to air filters. More particularly, it relates to air filters including pleated filter media that can be uniformly expanded and contracted. In some embodiments, the air filters are adjustably sized air filter systems. In some embodiments, the air filters can be used in a window opening.