Door

Apart from providing access into and out of a space, doors may have the secondary functions of ensuring privacy by preventing unwanted attention from outsiders, of separating areas with different functions, of allowing light to pass into and out of a space, of controlling ventilation or air drafts so that interiors may be more effectively heated or cooled, of dampening noise, and of blocking the spread of fire.

[1] Doors and doorways frequently appear in literature and the arts with metaphorical or allegorical import as a portent of change.

[2][3] Ancient doors were hung by pintles at the top and bottom of the hanging stile, which worked in sockets in the lintel and sill, the latter in some hard stone such as basalt or granite.

Cosmas and Damiano, in Rome, are important examples of Roman metal work of the best period; they are in two leaves, each with two panels, and are framed in bronze.

The Greek scholar Heron of Alexandria created the earliest known automatic door in the first century AD during the era of Roman Egypt.

[4] The first foot-sensor-activated automatic door was made in China during the reign of Emperor Yang of Sui (r. 604–618), who had one installed for his royal library.

The exact period when the builder moved to the hinge is unknown, but the change apparently brought about another method of strengthening and decorating doors—wrought-iron bands of various designs.

As a rule, three bands with ornamental work constitute the hinges, with rings outside the hanging stiles that fit on vertical tenons set into the masonry or wooden frame.

Doors of the mosques in Cairo were of two kinds: those externally cased with sheets of bronze or iron, cut in decorative patterns, and incised or inlaid, with bosses in relief; and those of wood-framed with interlaced square and diamond designs.

The doors of the palace at Palermo, which were made by Saracenic workmen for the Normans, are fine examples in good preservation.

A somewhat similar decorative class of door is found in Verona, where the edges of the stiles and rails are beveled and notched.

In the Renaissance period, Italian doors are quite simple, their architects trusting more to the doorways for effect; but in France and Germany the contrary is the case, the doors being elaborately carved, especially in the Louis XIV and Louis XV periods, and sometimes with architectural features such as columns and entablatures with pediment and niches, the doorway being in plain masonry.

The south door of Beauvais Cathedral is in some respects the finest in France; the upper panels are carved in high relief with figure subjects and canopies over them.

In St. Maclou at Rouen are three magnificently carved doors; those by Jean Goujon have figures in niches on each side, and others in a group of great beauty in the center.

The other doors, probably about forty to fifty years later, are enriched with bas-reliefs, landscapes, figures and elaborate interlaced borders.

High-speed cleanroom doors, usually consisting of a transparent material on a stainless steel frame, are used in pharmaceutical industries to allow passage between work areas while admitting minimal contaminants.

The powerful high-speed doors have a smooth surface structure and no protruding edges, allowing minimal particle retention and easy cleaning.

High-speed refrigeration and cold-room doors with excellent insulation values have also been introduced for green and energy-saving requirements.

It is important to get the hand and swing correct on exterior doors, as the transom is usually sloped and sealed to resist water entry, and properly drain.

An overhang is a roof, porch area or awning that helps to protect the door and its finish from UV rays.

German-made passive house doors use multiple weatherstrips, including magnetic strips, to meet higher standards.

That is split into four or five horizontal sections so that they can be raised more easily and do not require a lot of additional space above the door when opening and closing.

[25] The newer DIN 18101/2014 drops the definition of just five standard door sizes in favor of a basic raster running along 125 mm increments where the height and width are independent.

According to the US General Services Administration, discussing child care centres: ...It is essential that children's fingers be protected from being crushed or otherwise injured in the hinge space of a swinging door or gate.

Instead, an inexpensive device fitting over hinges is available on the market and should be used to ensure safety...[28]Whenever a door is opened outward, there is a risk that it could strike another person.

Doorstops are simple devices that prevent a door from contacting and possibly damaging another object (typically a wall).

Anti-finger trapping devices in front may leave the rear hinge pin side of doors unprotected.

Vehicle doors present an increased risk of trapping hands or fingers due to the proximity of occupants.

[31] In aircraft, doors in a pressurized cabin or cargo hold could pose risk if they open during flight, causing decompression.

Air may rush out of the fuselage with sufficient velocity to eject unsecured occupants, cargo, and other items, and drastic pressure differences between compartments may cause aircraft floors or other interior partitions to fail.