Psychrometrics with Excel 1

[navynuke]

Has anyone here every written a macro for calculating wet bulb temperature given the dry bulb temperature and relative humidity? According to Ashrae it can be done but requires solving several equations simultaneously which I am a little too new to VBA to do.

If anyone knows of any additional formula's for doing this I would greatly appreciate you sharing them.

 

[gtsim]

Hi Try this website it gives all the equtions you need.

http://www.srh.noaa.gov/elp/wxcalc/formulas/rhTdFromWetBulb.html

Regards,
gtsim

 

[mauner]

navynuke

I downloaded this excel file three years ago and found it to very useful - and still use it today. You might find slight differences when using psychrometric charts but it appears to be negligible.

Randal C. Wilkinson, PE developed the VBA functions from ASHRAE methods. The subfunctions can be used like any other excel function. Free software website:

http://www.longviewweb.com/free.htm

PSYCHROMETRIC FUNCTIONS for excel 5.0

mauner

http://www.longviewweb.com/psychro.zip

 

[willard3]

This is so easy to do with a psychrometric chart and, in my case much quicker than bringing up an excel file and filling it in (I keep the chart at my desk).

 

[athomas236]

This question has been posted twice. It is also under engineering spreadsheets.

athomas236

 

[salopsage]

ASHRAE bookshop sell Psychometric analysis software that provides thermodynamic properties for statepoints given input of two parameters and that plots thermodynamic processes on psychometric charts.