Changing the coefficient of infiltration in Open Studio
I am trying to work on a single family slab foundation, vintage – 1960s (created in ResStock) model in open studio. I want to change the airflow changes/hour (ACH 50) for the model. From the IDF file I know that in order to change the ACH, I need to change the coefficient for infiltration. Is there any way to do this? I know I may be able to alter the Eplus portion of the measure in order to do this - but is there any other way to manually input the coefficient in Open Studio? Or any other advice to do this?
By coefficient I mean the c value in the IDF file. Below is an extract of the exported IDF file. I only know the c value (Program line 10). How do I modify that in Open studio? I do not have the infiltration in terms of cfm/sqft etc that can be input from the space type tab in OS.
To clarify: by "coefficient" are you referencing an input such as CFM/SQFT of exterior wall, CFM/SQFT, etc...? If so I have a straightforward response. This can definitely be directly altered in OS.
I'm not sure what measure it is that you are speaking of when you refer to "alter[ing] the Eplus portion of the measure."
I have modified my question above to try to answer your question.
Do you know what the coefficient represents? Is it unit-less?
And if I understand correctly, you have known values for this coefficient, but not for anything that will allow you to directly edit infiltration ACH or CFM/SQFT (?).
I am not sure what the coefficient represents exactly. It does seem to be unit less. Yes, I have a value I want to change for the coefficient. But I also do know the ACH 50 value. But not in terms of cfm/sqft etc. Can I directly use the ACH 50 value anywhere?
So if you look at the screenshot I sent, you can directly edit ACH, but I believe that this is "standard" infiltration. I'm not sure how this compares to ACH at a 50pa pressure difference, but my instinct would be that it is lower, maybe much lower (I'll leave that to someone else on the forum). If the input for ACH is not a close approximation of ACH50, I'm sure you can lookup some kind of conversion factor.