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Psychrometric chart

Psychrometric chart

Psychrometric chart

(OP)
Hi,

I'm presently working on a custom application involving a Visual basic program to calculate the enthalpy of humid air to avoid looking in a psychrometric chart.  I would like to now the way to calculate the water saturation value for a specific temperature.  What is the exact equation?  This curve corresponds to the 100% Relative humidity on the chart.  Any reference to a book or an internet site would be great.  I already use this one http://www.learninghelper.com/psyc/

What I'm looking for is the equation behind the numbers.

I know that h=cp.t + w.hv  
where h is the enthalpy
      cp is specific heat of air
      t is the temperature
      w is the water content
      hv is the enthalpy of water vapor at t

thanks,

RE: Psychrometric chart

ASHRAE Handbook, Fundamentals, chapter 6.

RE: Psychrometric chart

Try this web site: www.squ1.com

They have a few neat programs related to HVAC/R and Building dynamics.

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