kyle.bernhardt
2007-06-28, 06:04 PM
Revit MEP Community,
I wanted to ask the Plumbing users their opinion on a topic that's come up here within our Product Team. We have differing opinions from different sources. I'm hoping to gain some consensus from you all so we can move forward. The answer may well impact the way that we handle "potential" future functionality (I'm trying to be as vague as possible).
Currently in Revit MEP we keep track of flow on Plumbing Fixtures using Fixture Units (FU). These Fixture Units are then transmitted to the connected Pipes and add up as Branches connect to Mains. Eventually, you end up at the source of that System and have a total of Fixture Units for that system.
We currently use an approximation of the "predominantly Flush Valve" Hunter Curve (http://www.bellgossett.com/hunter-curves1.htm) to convert from Fixture Units to Actual Flow (GPM). As part of a process that "might" result in us adding the "predominantly non-flush valve" curve (no guarantees), we have come to the question of what to do in low Fixture Unit situations.
The Hunter Curves do not have well defined values at low Fixture Unit values. There is, however, the definition of a Fixture Unit of 1 FU = 1 GPM at low values, but this is not always accepted.
The reason that this matters is we convert the FU value to GPM on every Pipe, and it is this GPM value that will be used if the user chooses to use our Pipe Sizing tool. So, we see a couple solutions here.
Use the 1 FU = 1 GPM equivalency up to 5 GPM, where the Hunter Curves begin. These values will be passed into the Sizing mechanism.
Have an "Undefined" value for such pipes, and return the smallest possible size in the sizing routines.
Have a constant "minimum" value for flow at low flow values. This "minimum" value will be passed into the sizing routines, and given it's low value, most likely return the smallest pipe size (as long as something ridiculous like 1/8" pipe is available in the size list).
What choice would you all prefer? Or, are we missing an option 4?
Rather than sounding off on other capabilities or wish list items, please try and provide just your feelings on just this question. We have plenty of other threads to sound off :).
Thanks in advance for your response.
:beer:
Kyle
I wanted to ask the Plumbing users their opinion on a topic that's come up here within our Product Team. We have differing opinions from different sources. I'm hoping to gain some consensus from you all so we can move forward. The answer may well impact the way that we handle "potential" future functionality (I'm trying to be as vague as possible).
Currently in Revit MEP we keep track of flow on Plumbing Fixtures using Fixture Units (FU). These Fixture Units are then transmitted to the connected Pipes and add up as Branches connect to Mains. Eventually, you end up at the source of that System and have a total of Fixture Units for that system.
We currently use an approximation of the "predominantly Flush Valve" Hunter Curve (http://www.bellgossett.com/hunter-curves1.htm) to convert from Fixture Units to Actual Flow (GPM). As part of a process that "might" result in us adding the "predominantly non-flush valve" curve (no guarantees), we have come to the question of what to do in low Fixture Unit situations.
The Hunter Curves do not have well defined values at low Fixture Unit values. There is, however, the definition of a Fixture Unit of 1 FU = 1 GPM at low values, but this is not always accepted.
The reason that this matters is we convert the FU value to GPM on every Pipe, and it is this GPM value that will be used if the user chooses to use our Pipe Sizing tool. So, we see a couple solutions here.
Use the 1 FU = 1 GPM equivalency up to 5 GPM, where the Hunter Curves begin. These values will be passed into the Sizing mechanism.
Have an "Undefined" value for such pipes, and return the smallest possible size in the sizing routines.
Have a constant "minimum" value for flow at low flow values. This "minimum" value will be passed into the sizing routines, and given it's low value, most likely return the smallest pipe size (as long as something ridiculous like 1/8" pipe is available in the size list).
What choice would you all prefer? Or, are we missing an option 4?
Rather than sounding off on other capabilities or wish list items, please try and provide just your feelings on just this question. We have plenty of other threads to sound off :).
Thanks in advance for your response.
:beer:
Kyle