Re: [TRNSYS-users] psycrometrics called with a temperature below absolute zero

[a8304506@graduate.hku.hk]

Hello, Talib.

I cannot run your project file as I can't find the weather file required. 
Usually, when the mentioned error occurs, Trnsys should indicate which unit the
error arises from so that you can trace the problem.  Meanwhile, I have looked
into your .tpf file and I suspect that the problem comes from the cooling tower
as your specified air flow rate seems too small.  Moreover, the specified mass
flow rates for some of the pumps do not seem to comply with the specified
capacity of the chiller. It appears that you try to use a chilled ceiling
system to cool the building.  However, I can't find any link to input the
chilled water information into the building zone.  Rather, you just specify a
fixed chilled water supply temperature and flowrate in your .bui file.  Please
check.  Thank you!

Best Regards
Chun Kwong LEE
University of Hong Kong  

Quoting Talib Ahmadu <talibahmadu@yahoo.co.uk>:

> Dear all, please i need some one to help take a look at my model. I'm
> modelling an absorption cooling system that works on solar energy. i've tried
> out some suggestions but the simulation still ends abruptly with an error:
> "the subroutine SAT of the utility routine psychrometrics, which calculates
> the thermodynamic properties of moist air has been called with a temperature
> below absolute zero". I'm really stuck here, can some one please help out.
> I've attached the files to this message. tanks in anticipation. 
>