.BuildingSystems.Utilities.Psychrometrics.Functions.TDewPoi_pW_amb

Information

Dew point temperature calculation for moist air between 0°C and 30°C with partial pressure of water vapor as an input.

The correlation used in this model is valid for dew point temperatures between 0°C and 30°C. It is an approximation to the correlation from 2005 ASHRAE Handbook, p. 6.2, which is valid in a wider range of temperatures and implemented in BuildingSystems.Utilities.Psychrometrics.Functions.pW_TDewPoi. The approximation error of this simplified function is below 5% for a temperature of 0°C to 30°C. The benefit of this simpler function is that it can be inverted analytically, whereas the other function requires a numerical solution.

Interface

function TDewPoi_pW_amb
  extends Modelica.Icons.Function;
  input Modelica.Units.SI.Pressure p_w(displayUnit = "Pa", min = 100) "Water vapor partial pressure";
  output Modelica.Units.SI.Temperature T "Dew point temperature";
end TDewPoi_pW_amb;

Revisions

• October 4, 2014, by Michael Wetter:
  Removed extends BuildingSystems.Utilities.Psychrometrics.Functions.BaseClasses.pW_TDewPoi_amb as this gives a compile time error in OpenModelica as the input argument T cannot be found.
• March 9, 2012 by Michael Wetter:
  Added smoothOrder=99 and displayUnit for pressure.
• May 21, 2010 by Michael Wetter:
  First implementation.