Author Topic: Duct System Blending  (Read 477 times)

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Rob...

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Duct System Blending
« on: January 10, 2017, 08:02:26 am »
I'm curious as to the proper way to do this.

System description:

Outside air through ERVs to bring it up to a minimum temperature for ventilation air to heat pumps which recirculate some of the room air. Room air gets mixed with the ventilation air prior to going back to the heat pumps. Exhaust air going back to the ERVs is equal in volume to the ventilation air.

How many systems are needed? I'm thinking ventilation (conditioned OA), Supply, Return, and Exhaust at a minimum.

Would you make a separate system for that mixed air (ventilation and return) going back into the heat pump? It's basically a plenum that has both ventilation air and return air going through to a common output.

How would you mix the systems, ventilation and return? Does it need to be a plenum (or something else) that mixes the systems or can it be a duct?
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #1 on: January 10, 2017, 09:45:26 am »
You can tie two systems (duct to duct) together but the whole mess is VERY fragile -i.e. as soon as you connect/change systems again all associated and attached get all redefined. The easier solution is to create a mixing box family but you still only have a few built-in systems to choose from (SA, RA, EA). ...Yes the systems can get a bit tricky -i.e. exhaust air, tempered air, supply air, and return air but you're just going to have to "not fully connect" (if you establish all those duct systems)--but then you loose part of your calculations--or deal with the built-ins (SA, RA, EA)--potentially loose colors on the screen-.

FWIW: My systems are SA, RA, EA, & OA. and these are only for colors on the screen (in working views). The built-ins are really only to establish "symbols" (Cross, Slash, Wye) in the rises and drops and for calculation purposes.

Generally speaking in an average duct system you can have:
Supply
Return
Exhaust (Lab/Chemical/Biological & General)
Relief
Outside
Tempered


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Rob...

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Re: Duct System Blending
« Reply #2 on: January 10, 2017, 10:42:40 am »
You <-- Grain of salt.

What exactly does that mean?
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #3 on: January 10, 2017, 12:21:40 pm »
Take whatever I said with a grain of salt.

https://en.wikipedia.org/wiki/Grain_of_salt
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Rob...

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Re: Duct System Blending
« Reply #4 on: January 10, 2017, 01:06:04 pm »
Okay, thanks.

At first, I thought you comparing me to something less than a grain of salt. I did think of that saying but I didn't see how it fit here.
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Rob...

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Re: Duct System Blending
« Reply #5 on: January 10, 2017, 01:38:07 pm »
I've decided to try it with a duct for no other reason than I don't want to figure out how to tag a plenum/mixing box right now.

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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #6 on: January 10, 2017, 03:33:06 pm »
Sounds good.

BTW, those better not be colors driven by "graphic overrides" (like in the default revit templates). ...just saying.
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Matt__W

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Re: Duct System Blending
« Reply #7 on: January 10, 2017, 04:14:54 pm »
Sounds good.

BTW, those better not be colors driven by "graphic overrides" (like in the default revit templates). ...just saying.
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Rob...

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Re: Duct System Blending
« Reply #8 on: January 10, 2017, 04:19:03 pm »
"I don't need no stinkin' standards."

Actually, I'm not even sure what is not an override other than the default white/black.

The colors are assigned by system graphic overrides. Trying to keep it simple as we bang out the first couple of Revit projects this company has had. Everyone is into it, so far. Quite a different experience compared to what happened at my last place when we first started out with Revit. Oh, that was bad...
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #9 on: January 10, 2017, 04:23:11 pm »
I only have two words to say to you: your plotting will be fun (read: crappy)!
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Rob...

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Re: Duct System Blending
« Reply #10 on: January 10, 2017, 04:25:09 pm »
No problems with plotting. Why do you say that?
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Rob...

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Re: Duct System Blending
« Reply #11 on: January 10, 2017, 04:28:27 pm »
What is going on here? First you say I'm less than a grain of salt and now my plots will be crappy? I haven't felt this insulted in a while.
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #12 on: January 10, 2017, 04:30:55 pm »
Plotting "black lines" doesn't work great with screened lines and "greyscale" doesn't give you the best control over things either. ...you should be working in "working views" with colors and have your "plot views" filters set the color to no color.

...ha! I think I still have his email address if you want it.
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #13 on: January 10, 2017, 04:31:52 pm »
And, what kind of insult is "less than a grain of salt" anyways!?
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Rob...

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Re: Duct System Blending
« Reply #14 on: January 10, 2017, 04:48:07 pm »
I've been using black lines for years and am satisfied with the results. Our plots could be better and I'm pretty sure I can get there utilizing black lines, but at this point, why bother? Color plots are right around the corner and that is an entirely different beast. They already have a large format color plotter. Plus, their AutoCAD plots are fairly simple and could use a lot of refining. As long as the bosses are happy, less that I have to worry about at this point. Like assigning pipe system colors, plotting is one of those things that I can drive myself crazy with. I've got bigger fish to fry. Gotta wean them off the AutoCAD teats. So far, it's just floor plans in Revit.

I have working views. They actually look quite similar except for seeing the other trades, a higher detail level, and have no annotation, although I could use them for notes.

As to the email, thanks, but no thanks. LOL!
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Rob...

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Re: Duct System Blending
« Reply #15 on: January 10, 2017, 04:50:15 pm »
And, what kind of insult is "less than a grain of salt" anyways!?

Think about it. If someone that you respected said to you that you are less than a grain of salt, how would you feel? I'd feel pretty insignificant.
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rvhwlc

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Re: Duct System Blending
« Reply #16 on: January 10, 2017, 05:41:40 pm »
system .graphic overrides can be overridden with filters..

Rob...

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Re: Duct System Blending
« Reply #17 on: January 10, 2017, 05:44:11 pm »
I like me those filters.
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Matt__W

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Re: Duct System Blending
« Reply #18 on: January 11, 2017, 07:27:13 am »
I came across this nice little graphic yesterday showing the element visibility override hierarchy.

https://twitter.com/RobCross247/status/818764726066880513
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #19 on: January 11, 2017, 09:01:20 am »
system .graphic overrides can be overridden with filters..
Wait a minute! ...I could have sworn that system's graphic overrides had more preference then view filters. I'm off to run a quick test (should be easy enough to test). I guess you can. But the question of "why" still remains.
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rvhwlc

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Re: Duct System Blending
« Reply #20 on: January 11, 2017, 10:40:52 am »
system .graphic overrides can be overridden with filters..
Wait a minute! ...I could have sworn that system's graphic overrides had more preference then view filters. I'm off to run a quick test (should be easy enough to test). I guess you can. But the question of "why" still remains.
I do not use graphic overrides.. but many people do.. and it messes my models up so i have .filters to override it so it's all black lines when i use their files as links, etc.. this helps flow for me

plumbing single line makes a lot of sence for filters.. because of single line.. so you can see the systems, then apply filters to sheet views to make all black.. only time i see them as useful.

Rob...

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Re: Duct System Blending
« Reply #21 on: January 11, 2017, 04:36:08 pm »
Funny coincidence happened today. Our BIM Coordinator came up to me today and asked me if I was using overrides for my system colors and mentioned plotting. I easily convinced him to go with black lines, for now. Just because, at this point, it needs no additional set-up and resembles their AutoCAD plots as a result of very little leg work on my part. I transferred their lineweights to Revit and, subsequently, object styles not long after I started. The conversation quickly turned to color plots and I think we may start heading in that direction rather than put much time into black lines and or gray scale.

I do have a question for you guys. Do you have a color version of your annotation views as well as the black and white ones for plotting?
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #22 on: January 12, 2017, 08:30:22 am »
I turned off Graphic Overrides along time ago. I use a simple tiered system of view templates which I can use to turn colors off/on or to different colors. Having the default be black makes it easier to not screw up and not such a pain for others who link in my model, in my opinion. So, my answer is: I can turn colors off/on in any view I want to.

My setup:
I have a "Working view" with colors and a "Plotting view" with no colors.
« Last Edit: January 12, 2017, 09:28:13 am by John Kaul (Se7en) »
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John Kaul (Se7en)

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Re: Duct System Blending
« Reply #23 on: January 12, 2017, 08:38:16 am »
system .graphic overrides can be overridden with filters..
Wait a minute! ...I could have sworn that system's graphic overrides had more preference then view filters. I'm off to run a quick test (should be easy enough to test). I guess you can. But the question of "why" still remains.
I do not use graphic overrides.. but many people do.. and it messes my models up so i have .filters to override it so it's all black lines when i use their files as links, etc.. this helps flow for me

plumbing single line makes a lot of sence for filters.. because of single line.. so you can see the systems, then apply filters to sheet views to make all black.. only time i see them as useful.

Neither do I. Naughty little things aren't they.

Really, you think a lot of people still use graphic overrides? Yuck, that must make for interesting coordination. Aside: I wonder if you convert to IFC then back into Revit if those colors would go away. ...When I get on "one-of-those" projects, I often contemplate using IFC as a scrubber of sorts but I've never gotten around to testing the validity of it (does everything make the trip, would it be easier/better, etc.).

Yes, me too. 
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Rob...

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Re: Duct System Blending
« Reply #24 on: February 24, 2017, 02:39:17 pm »
Back on topic.

I've decided to simplify the systems associated with the VRV FCUs that are recirculating the room air and mixing it with supply air from the ERVs. I'm going to make everything supply. We have exhaust/return going back to the ERVs. I think I was trying to overthink it before.
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