In a standard office project, we normally take the Plumbing Fixture Unit schedule (containing fixture units per type and total count of all units), sum the fixture units of all the fixtures, get the % of grand total of each, divide the fixture units by the % to push the total fixture rate back into each instance, and then curve-approximate to different parts of Hunter's curve to push out a demand GPM that's usually within 10% of the charted amount.
The end result is a tiny little table for designers to check the incoming line size for velocity (yes the code cycle is not updated):
Where it stops being a clean fit is if we have to incorporate fixtures that have listed flow rates that do not conform to the fixture unit designation outlined by the local code. For instance, commercial kitchen fixtures with defined flow rates, hose stations in production warehouses, hose bibbs using the IAPMO fixed flow rate, etc... these are normally manually added onto our calculations after the fact as a lump sum. This unfortunately means that the 'final' value used to calculate pressure is inputted by hand after a hybrid automatic/manual workflow, which means someone will eventually forget to do the manual part and create a complication.
So, I'm trying to incorporate the lump sum values in to the same table that does the fixture unit calculation.
If I attempt to sum and push the non-FU flow rates into each plumbing fixture in the same manner, we start getting divide-by-zero issues all over the place due to the Flow/% formula, which breaks the subsequent total flow and pipe size values. This is the same table, with columns expanded.
All of this can be avoided if I simply do the summations in Dynamo and push the summations back to the equipment via Dynamo script. But before I add another script to the pile, is there another option via Revit tables that I'm overlooking?
