[TRNSYS-users] Differenece in massflow calculation for shaft opening TRNSYS-Type97 and CONTAM

[Philipp Lezajic]

Hi,

when using the "shaft" airflowpath in a building model in CONTAM I get different massflows compared to using the model via type 97 in TRNSYS. I use the "steady" simulation mode in CONTAM and aply the same parameters (zone-temp, amb-temp, amb-pressure,etc.) to type 97 as inputs. For other airflowpaths (like the two way flow -- two opening used in the calling CONTAM example) the massflows are equal in TRNSYS and CONTAM. 
The difference is not very big for one shaft airflowpath, but as my building model has several zones on top of each other connected with shaft airflowpaths (an atrium) the difference in my case is around 5%.


Is there a difference because CONTAM and TRNSYS solve the same equation system with a different solver? How can this difference be rated? Are there any parameters in under Control Cards in the Simulation studio that I can adapt?

Again thanks in advance to everyone for help or advice!

regards Philipp






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