the space behind the door.
Screen Doors
Although not technically storm doors, since they do not provide a barrier to wind and rain, plain screen doors have been in use for more than a century. Designed to allow the breeze, while preventing flies and other insects from entering your home, screen doors are typically built with a light aluminum or wooden frame. They swing on face mounted hinges, and are typically connected to a spring or pneumatic closer to keep the door shut.
Full Glass Doors
Full glass or unvented doors are designed not to obstruct the view while still maintaining some climate control. Unvented doors typically have a single, uninterrupted glass panel running from the frame at the top to the frame at the bottom. Some are constructed with a short metal panel at the bottom of the glass. Unvented storm doors are mounted in a metal frame that attaches to the face of the entrance door's jamb.
Lower Vents
Traditional storm doors have a metal panel at the bottom about 1/3 the height of the door. Directly above this the glass is divided horizontally into two panes. The lower pane is a sliding glass panel that can be raised to open and slides down to close. The glass panel, or vent, slides in channels at the sides of the door and features spring loaded tabs at the bottom corners to lock the glass in the down position. A screen on the outside of the door keeps insects out. When the tabs are released in the up position, the vent will stay open at the desired height.
Upper Vents
Some full-glass and half-glass doors also have upper vent panels. On the full-glass models, the glass drops down behind the lower glass and features a screen on the outside. On the half-glass models, the glass is divided into two panes, much like the lower vent models. The lower pane of this vent lifts up to open. A screen mounted from the outside keeps flies and other bugs away.