<Document>
  # Air Vent
  The air vent is a standard vent, found in all rooms that you want to pressurize with a breathable atmosphere.
  Its primary job is to transfer gasses into the atmosphere it's exposed to until it reaches a set pressure.

  <Box>
    <GuideEntityEmbed Entity="GasVentPump"/>
  </Box>

  The air vent requires [textlink="power" link="Power"] through a nearby [textlink="LV cable" link="VoltageNetworks"] to function.

  The air vent can be welded with any welding tool to stop it from functioning.

  ## Default Operation
  The default behavior of an air vent is to simply output gas to the exposed atmosphere at a pressure of [color=orange][protodata="GasVentPump" comp="GasVentPump" member="DefaultExternalBound"/] kPa[/color].

  The speed of the air vent scales with the difference between twice the connected [textlink="pipenet's" link="PipeNetworks"] pressure and the pressure of the exposed atmosphere.
  To put it in a word equation:
  <Box>
    [italic]Speed = 2 × Pipenet Pressure - Exposed Atmosphere Pressure[/italic]
  </Box>

  For example, this means that an air vent will be unable to pump to 101.3 kPa if the gas inside the vent goes below half that.

  ## Pressure Lockout
  Air vents will enter [color=red]pressure lockout[/color] when the pressure of the atmosphere it's exposed to is below [color=orange][protodata="GasVentPump" comp="GasVentPump" member="UnderPressureLockoutThreshold"/] kPa[/color].
  This is to prevent wasting useful gasses to space if a room is not sealed.
  The lights on the air vent will turn [color=yellow]yellow[/color] to highlight this change.

  This can be [color=green]overridden[/color] by right-clicking on the vent and selecting 'Release pressure lock out', or setting the mode to Fill on a connected [textlink="air alarm" link="AirAlarms"].

  It is important to note that air vents in [color=red]pressure lockout[/color] still very slowly leak out gas.
  The amount of gas they leak out is relative to the current pressure of the pipenet they're connected to.

  ## Configuration Options
  When [textlink="linked" link="Networking"] to an [textlink="air alarm" link="AirAlarms"], air vents gain more functionality.

  Air vents have two "vent direction" options: Releasing and Siphoning.
  - Releasing simply releases gasses into the atmosphere from the connected pipenet.
  - Siphoning sucks the air out of the atmosphere and into the connected pipenet. The lights on the air vent will turn [color=red]red[/color] to highlight this change.

  ## Pressure Bounds
  Air vents have a pressure bound system, which controls the pressure at which an air vent will pressurize an atmosphere, or draw from a connected pipenet. These limits are taken into account in both releasing and siphoning modes.

  The "PressureBound" setting has four options:
  - ExternalBound makes the air vent respect the pressure limits defined in the External bound entry.
  - InternalBound makes the air vent respect the pressure limits defined in the Internal bound entry.
  - Both makes the air vent respect the pressure limits defined in both the External and Internal bound entries.
  - NoBound makes the air vent respect no limit.

  When the vent is in releasing mode:
  - If the External bound pressure is set to 101.3 kPa, the air vent will not pressurize the atmosphere above 101.3 kPa.
  - If the Internal bound pressure is set to 50 kPa, the air vent will not draw gas from the connected pipe if its pressure is below 50 kPa.

  When the vent is in siphoning mode:
  - If the External bound pressure is set to 101.3 kPa, the air vent will siphon gasses until the atmosphere reaches 101.3 kPa.
  - If the Internal bound pressure is set to 50 kPa, the air vent will not push gasses into the pipenet if its pressure is above 50 kPa.

  If you're still confused about PressureBounds, here's a simple way to think about it:
  - You can think of the External bound as the upper limit for the exposed atmosphere. "I will not pressurize the exposed atmosphere past this pressure, or draw from the atmosphere below this pressure."
  - You can think of the Internal bound as the lower limit for the connected pipenet. "I will not draw from my source below this pressure, or push air into the pipenet above this pressure."
  - The "Pressure bound" settings simply define which limits to respect or ignore.

</Document>
