re: found error in weather file and air layer question

[DAS_Ryerson]

I have found an error in the weather file ASHRAE yr 1, Toronto at timestep 6207, exterior RH% reads 1830. For the meanwhile, this error has led to convergence errors that have been corrected with high# of adaptive timesteps and dense grids and high CPU time.

I wanted to know if it was possble to get a copy of the *.wac file with this error corrected in short measure. If not I will have to ignore this for now or use year 3 weather file.

I have been using the "without additional moisture capacity" air layer. I have noticed since some of my older files from either (5.0 or 5.1, i don't remember) that the porosity was changed to 0.999 from 0.001. I am assuming for stability purposes this was done. Is the difference in accuracy usually negligible?

I thought that by defining the storage function of the air layer, the moisture content cannot spike past saturation, but that is not the case.
During the errorous timestep, the mc of the layer shot up to 950%

thanks
-cory

[Christian Bludau]

Hello Cory,
you are right, there are two errors in the Toronto climate file. The people at ORNL will fix that soon. I hope we have a new version by the end of the week.
Unfortunately I can not give you the wac-file, as we are not allowed to provide them and I do not have the raw data.
We will come back to you after the file is corrected.

About the air layers:
The porosity was increased to allow the layer to accumulate more water, and it is also more stable in the calculation. The free saturation is the value the material can store at 100% RH, thats right. But a (porous) material can take up more water, the maximum saturation is defined by the porosity. So if you set the porosity to 0.001 and get dew water in your layer, the air layer can not take up the water and so you can not analyze its amount. If you use porosity 0.999, all the water (even that which would normally run out of your air layer) is taken up and can be analyzed.
That's the reason you got up to 950% mass-percent and water content higher than free saturation.

Please also see the info-text for the airlayers for further information.

Regards,
Christian

[Manfred Kehrer]

Installation File Install_ORNLClimate.zip at the download page of WUFI.com with Version 1.1.0.3 will include a corrected YEAR1 climate file for Toronto.
Probably by July/19/2013

[Thomas]

Installation File Install_ORNLClimate.zip at the download page of WUFI.com with Version 1.1.0.3 will include a corrected YEAR1 climate file for Toronto.
Probably by July/19/2013

The updated file is online now:
http://www.hoki.ibp.fraunhofer.de/downl ... .1.0.3.zip

Bye,
Thomas