Hi @edpmay, is there a way to specify ventilation rates in air changes per hour? I’m going through your tutorials and the “Set TFA params” command appears to only take m3/h, which means I need to get all the room volumes and make the conversion for each room, then enter it manually in Rhino.
I know you prefer the manual way but in my case I’ve got a fairly large building with many rooms and would prefer to automate this in Grasshopper.
Just realised it works if I give it a base program
However, when I go to the PHPP, I can see that the total ACH is set to 0.25 instead of 0.3 as specified:
Is this because the total ACH refers to the ACH per GFA but what I’m specifying in HB is the ACH per GFA?
Glad you were able to get it working. And yes I think you are exactly right: the difference there is that in PH-models they want to use the ‘net-interior’ volume as the reference volume for all of those items (ventilation, infiltration) whereas E+ uses gross volume. So yeah: 0.25ACH wrt the gross will be a higher ACH wrt the net. Frustrating I know - would be much easier if everyone used the same reference dims.
But to your question: no - I hadn’t thought to include a ‘setter’ for ACH-based ventilation flow I’m afraid. That’s a great idea though and I’'ll be sure to add to the V2 we’re working on. For the time being I think you’d need to calc the airflow rates manually for each space I’m afraid.
Sorry about that!
best,
@edpmay
Thanks for clarifying and no need to apologise! Thanks for putting out this great tool and developing it further.
I think that this has mostly been addressed via this topic:
The only thing that wasn’t really addressed there is the ability to get net volume instead of gross volume. I think this is something that I would add if I addressed this issue:
So, if this is something that you think you’ll want sooner than later, than 
that issue and I’ll prioritize it.
Hi @chris. I know this quite a old post but I was curious to know if this feature will be implemented soon!. Any thought on this?
There have just been other things that have been taking priority, @Asisnath . The honeybee-energy OpqaueConstruction classes already has a thickness property, so if someone wanted to implement this, all that they would have to do is subtract these thicknesses from the floor areas. The only part that requires a little extra work is identifying the edges between Walls and Floor Faces but this should be straightforward with ladybug_geometry.
