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A while ago I built all my duct fittings and duct accessories to use the correct C-values for pressure drop calculation . Instead of using the (often wrong) ASHRAE method, i base this on SMACNA or manufacturer data.One trick for ducts is, i have to manually set the calculation method to "none "for it to use only my c-values. I also have to have the family calculate the pressuredrop instead of the duct connector C-function.
Now i want to do the same for piping. I now K- and Cv values and also can derive them for specific equipment manufacturer data. I'm just not sure how well Revit uses them (knowing for duct it also has quirks)
I have the families set up to be a type per nominal size and K- or Cv values also often depend on nominal size. So a method to use a specific K- or Cv-value per type looks the best so far.
My goal is to not have to manually make adjustments and to have good design values that are conervative, but still reflect the type of device (e.g. a ball valve should have less pressure drop than a globe vale)
I'm using a valve (pipe accessory) as an example.
If i select a single valve, I can select a loss method and the appropriate type for the K. I suspect this can't be hard-coded to the type and has to be set for each instance (not what I want)
In the family editor i can set each type to use a K value from the table and select the type:
but I can't see what K-value it uses.
On the connector I can designate it to use the K-Coefficient and can assign it a parameter.
So far it looks I want to either use the "from table" K value per type, or a manually determined K-value on the pipe connector.
Can someone explain how all 3 ways to use a K- value (the one per instance, and 2 that seem per type) relate to each other and which one will be used? I'll try to play around and review the pressure reports. but i wonder if someone did that before and can give some hints?
A while ago I built all my duct fittings and duct accessories to use the correct C-values for pressure drop calculation . Instead of using the (often wrong) ASHRAE method, i base this on SMACNA or manufacturer data.One trick for ducts is, i have to manually set the calculation method to "none "for it to use only my c-values. I also have to have the family calculate the pressuredrop instead of the duct connector C-function.
Now i want to do the same for piping. I now K- and Cv values and also can derive them for specific equipment manufacturer data. I'm just not sure how well Revit uses them (knowing for duct it also has quirks)
I have the families set up to be a type per nominal size and K- or Cv values also often depend on nominal size. So a method to use a specific K- or Cv-value per type looks the best so far.
My goal is to not have to manually make adjustments and to have good design values that are conervative, but still reflect the type of device (e.g. a ball valve should have less pressure drop than a globe vale)
I'm using a valve (pipe accessory) as an example.
If i select a single valve, I can select a loss method and the appropriate type for the K. I suspect this can't be hard-coded to the type and has to be set for each instance (not what I want)
In the family editor i can set each type to use a K value from the table and select the type:
but I can't see what K-value it uses.
On the connector I can designate it to use the K-Coefficient and can assign it a parameter.
So far it looks I want to either use the "from table" K value per type, or a manually determined K-value on the pipe connector.
Can someone explain how all 3 ways to use a K- value (the one per instance, and 2 that seem per type) relate to each other and which one will be used? I'll try to play around and review the pressure reports. but i wonder if someone did that before and can give some hints?
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