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Renata
13-09-2016, 02:34 PM
Hi every one...

I am new in this forum, I am a industrial refrigerantion engineer in Brazil since 2008.
Right now, I need some help to find an equation or software or anything else to calculate wet bulb temperature from dry temperature and humity...

Thanks!
Renata

Josip
13-09-2016, 03:36 PM
Hi, Renata :)

welcome to RE forums...


Hi every one...

I am new in this forum, I am a industrial refrigerantion engineer in Brazil since 2008.
Right now, I need some help to find an equation or software or anything else to calculate wet bulb temperature from dry temperature and humity...

Thanks!
Renata

maybe this will be of some help ... the last one is not bad;) ... enjoy ....

http://www.srh.noaa.gov/epz/?n=wxcalc_rh

https://www.easycalculation.com/weather/dewpoint-wetbulb-calculator.php

http://www.daikin.be/en/support-and-manuals/software-downloads/
http://www.daikin.be/en/binaries/Psychrometrics_tcm505-229283.zip


Best regards, Josip :)

cduque
13-09-2016, 06:58 PM
Hi Renata,

I use a formula from a study of Roland Stull - University of British Columbia, Vancouver, that gives an approximative value good enought for me. It is valid from -20ºC and +50ºC except for situations both with low humidity and temperature. You can try it:

T.BH = T.Seca *ATAN(0,151977*(HR +8,313659)^(1/2))+ATAN(T.Seca +HR )-ATAN(HR -1,676331)+0,00391838*(HR )^(3/2)*ATAN(0,023101*HR )-4,686035

There are others more simple but with worst results.

Best regards,
Carlos Duque

Sandro Baptista
14-09-2016, 01:05 PM
Hi Renata,

You can use the psychrometric chart. You get the point for the dry bulb temperature and relative humidity you have and then you follow the line with constant enthalpy (the evaluation is aproximately an adiabatic/constant enthalpy) and you get the wet bulb temperature on the saturation temperature of the air on the limit curvy line, at 100% relative humidity.

cduque
14-09-2016, 04:19 PM
You can also use one of the many Psychro applications existing for PC, IOS or Android.
For example for PC you can try:
https://www.munters.com/en/specific-pages/airt-forms/psycalc-download-form/psycalc-psychrometric-software/

Renata
15-09-2016, 03:25 PM
Thanks a lot!

Renata
15-09-2016, 03:27 PM
cduque,
It will help me a lot, thank you very much.

Renata
15-09-2016, 03:32 PM
Thanks, Sandro, but I was looking for an automatic method, because I will use in a excel sheet with many data points.

Sandro Baptista
15-09-2016, 05:23 PM
Thanks, Sandro, but I was looking for an automatic method, because I will use in a excel sheet with many data points.

Ok. I see.

"Já agora, bem vinda ao forum da refrigeração. De que zona do Brasil és?" ;)