Looped pipe system

[michael.194819]

Hi, everybody
I cant get my pump with multiple heating coils system to work!!!! What im trying to do is create a system that can add up heating coils' flow and sum it up at the pump.... In order to do that, I created 2 different water flow base parameters, one at the inlet(calculated, In) and one at the outlet(Preset, Out). Then I created one more parameter called GPM, and create the formula GPM IN (Iinlet) + GPM = GPM Out (Outlet). The formula worked great, it added up flow of Heating Coil 1,2,3 just fine. However, once the pump takes in the flow, it shoots the information right back to Coil 1. In turn, add all three Coil's flow to Coil1's inlet, which pass the additional flow to Coil2. So, by the time it gets to Coil3, the flow is 5 times more than design......
So please take look at it..... and if there is any better way to do this, please let me know.

[kyle.bernhardt]

Michael,
So I'm going to assume that you didn't intend to break the laws of physics by creating flow from nothing, thus I have modified your original configuration, as well as the families themselves. I've attached the modified model for your review.

Since it's late and I need to go to bed, here's a quick run-down of the issues.


Based upon your statement of the issue, it seems like you want the Coil to be the defining element of your system. Because of that those Elements need connectors defined with the Preset Flow Configuration parameter setting. This way they define the flow for the connected pipe and eventually the Pump.
The pump had to be configured so both Connectors were set to be Calculated Flow Configuration. Since the both Supply and Return Systems are set up to be balanced by-design in this case, I've gone ahead and mapped the Pump Connectors to the same Flow Parameter on the Family.
I had to define separate systems, as I assumed you were shooting for a Parallel flow here based upon your initial description. If you are indeed looking for Series flow in your Pipe system, you'll need to re-configure the Familes and the pipe network. That one's a bit more tricky (and less common), but possible. I just assumed this was not the case.
Cheers,
Kyle B

[1N.]

[---- intend to break the laws of physics by creating flow from nothing, thus I have modified your original configuration, as well as the families themselves. -

Kyle,

I was wondering how you feel about Drain connectors in general . Lets Water heater or Roof top units for example. Do you need a connector and what kind of settings you'll recommend on it if is not connecting to piping system.
I do show Drain connector in my families and have Drain Flow and Drain Pressure Drop Parameters with Preset/Out/Specific Loss setting and both parameters mapped to it, but I wonder if that’s not overkill. What do you think is the minimum here?

[kyle.bernhardt]

[---- intend to break the laws of physics by creating flow from nothing, thus I have modified your original configuration, as well as the families themselves. -

Kyle,

I was wondering how you feel about Drain connectors in general . Lets Water heater or Roof top units for example. Do you need a connector and what kind of settings you'll recommend on it if is not connecting to piping system.
I do show Drain connector in my families and have Drain Flow and Drain Pressure Drop Parameters with Preset/Out/Specific Loss setting and both parameters mapped to it, but I wonder if that’s not overkill. What do you think is the minimum here?

If you're not connecting piping to the drain connectors, the minimum here may be "nothing at all". The connector itself really isn't accomplishing much without pipe connections. It sounds like you have some parameters to hold connection information, but you can do that without the connectors themselves.

I would expect these to more confusing to users than anything, since they aren't intended to be connected to anything.

If you actually were modeling the drain piping, I'd set the Connector to Sanitary, Flow Configuration of Preset, and a Flow Direction of Out.

Cheers,
Kyle B

[1N.]

I am planning to run some piping to the floor drain and I can create system too, but for some reason sizing is not working no matter what I put on the drain connector. Not working I mean the field for sizing is grayed out... I checked all the Autodesk families I checked McQuay and Trane families:
Autodesk sometimes adds Drain Flow parameter and maps to the connector. No Drain pressure drop. Settings vary between Preset/OUT/Not Defined to Calculated/Out/Specific Loss...it almost seems like is looking for fixture units in order for the sizing to work.
I am also confused on gas(or steam) connectors. The only way you can have the flow is in GPM. If I change the project units of the flow to none everything else is changing for all the flows. So I guess the question is if I have gas connection on any mechanical equipment I am saying that is going to be Preset /In/ Specific Loss and I need to have Gas Pressure Drop and Gas Flow Parameters to map to the connector? So again gas flow in GPM? Do I need both flow and pressure drop mapped to the connector so the sizing actually works.(Preset/in/Specific Loss for gas?) most families that I reviewed are not mapping to gas flow. I do get the idea about data propagating thru the system and is not in the same direction as the system flow sometimes, but really not understanding why the flow of piping systems are not readable on the connectors similar to Duct connectors. I hope you understand the few questions I have here... I do realize I am all over the place. Pretty sure that connector settings is the Revit part that is really not user friendly and difficult to comprehend and is not explained well. BTW thanks for your movies on connectors that helped a lot. Again after one year of struggling I think I understand connectors and systems well at least mechanical, but still struggling with piping. Looking forward to the new version.
I don't care about the ribbon and not going to complain about it, but really hoping to see increase in performance.....working on 80MB model with decent system and is just slow..slow...slow...

[eglover]

I am also confused on gas(or steam) connectors. The only way you can have the flow is in GPM. If I change the project units of the flow to none everything else is changing for all the flows. So I guess the question is if I have gas connection on any mechanical equipment I am saying that is going to be Preset /In/ Specific Loss and I need to have Gas Pressure Drop and Gas Flow Parameters to map to the connector? So again gas flow in GPM?

I don't know anything about the rest of your issues, but I think I can help you with this one. When you set your project units, set them to whatever you will use most (in this case, GPM). Set up separate shared parameters for liquid and gas connections. Then when you schedule the equipment, you can determine the units for each separately.

To do this, you go to view properties of the schedule, go to formatting, chose the field you want to change the units for, and click "Field Format". From there, uncheck the "Use default settings" option and change your units and/or labels. This way, you can enter the info however it makes sense. If you don't want to schedule the information, I still think it might be worthwhile to create a dummy connection schedule to enter information and then just don't add it to a sheet.

[1N.]

I don't know anything about the rest of your issues, but I think I can help you with this one. When you set your project units, set them to whatever you will use most (in this case, GPM). Set up separate shared parameters for liquid and gas connections. Then when you schedule the equipment, you can determine the units for each separately.

To do this, you go to view properties of the schedule, go to formatting, chose the field you want to change the units for, and click "Field Format". From there, uncheck the "Use default settings" option and change your units and/or labels. This way, you can enter the info however it makes sense. If you don't want to schedule the information, I still think it might be worthwhile to create a dummy connection schedule to enter information and then just don't add it to a sheet.

Actually I do know that I can change the units in the schedule, I guess my question was more about connectors and how the gas/steam flow units will affect the gas pipe sizing. I haven't beem able to make gas piping sizing work in Gas system. I can't figure out if I need gas flow parameter at all in order to do that. When I have gas system and select pipe Revit sizing is not active so I just size my pipe the way I usually do and give the size I calculated. Not sure if I am missing something or Revit is not there yet.