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What tool do you use to draw schematic of air loops and plant loops?

asked 2015-10-23 07:45:00 -0500

updated 2015-10-23 08:44:35 -0500

Whether you want to communicate with someone, plan your approach for modeling or label your nodes for an EnergyPlus simulation, it's often useful to draw out a schematic of an air loop or a plant loop, so you can see all the equipment and connections you need.

I usually do that by hand, but it's not easy to share it or to modify it. Using AutoCad for that is overkill.

I was wondering if people have found an easy to use and quick sketching tool, preferably free (and open source even better).

Ideally I'd like something with a library of common things where you can drag and drop your objects, and snap some connecting lines forced at a 90° angle. If you move an equipment, all connections would still be snapped to it. It would ideally also handle nicely lines crossing each other (creating bridges)


Here is an example of what I may want to draw:

Example of a plant loop

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I assume you are looking for something that allows you to edit at the component level. What you are describing sounds a lot like OpenStudio. What am I missing? Or what is OpenStudio missing? Does it do too much checking for what you are looking for? Is it that it forces you to have too much of the rest of the model?

__AmirRoth__'s avatar __AmirRoth__  ( 2015-10-23 08:20:06 -0500 )edit

You should update your gravatar, you aren't globally recognizable in it.

__AmirRoth__'s avatar __AmirRoth__  ( 2015-10-23 08:21:09 -0500 )edit

I just want to sketch something, and I might want to add like a 2-way valve if I want to, or I may want to show both the condenser and chiller water loop at the same time. I like what OpenStudio has for air loops and plant loops, but I could use more flexibility.

Julien Marrec's avatar Julien Marrec  ( 2015-10-23 08:31:54 -0500 )edit

(and no, I won't change my gravatar. It's the only way I can still go incognito to some places. Otherwise people keep stopping me everywhere, being all like "Hey, aren't you on this uber famous website called UnmetHours?", it's affecting my personal privacy)

Julien Marrec's avatar Julien Marrec  ( 2015-10-23 08:34:09 -0500 )edit

@Julien Marrec, we have discussed concept of a multi-loop view where you can see connections, but not on our radar at all. Certainly something you can add to user voice. As far as diagraming software I haven't used yEd for HVAC, but I use it for many other things. It is free, pretty intuitive, and powerful.

David Goldwasser's avatar David Goldwasser  ( 2015-10-23 09:46:43 -0500 )edit

7 Answers

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answered 2015-10-24 02:38:13 -0500

Lucidchart is great for this kind of drawings. It connected to Google Drive, free, and better than Visio.

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Lucidchart is what I tend to use as well.

Jamie Bull's avatar Jamie Bull  ( 2016-10-09 17:34:12 -0500 )edit

answered 2015-10-23 12:13:10 -0500

Archmage's avatar

updated 2015-10-23 12:57:07 -0500

I use Visio. The dynamic connectors work fairly well. And it feels seamless for figures in Word.

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answered 2015-10-23 09:11:45 -0500

I use powerpoint, it isn't great I will give you that but it is very flexible and once you have one schematic drawn out it doesn't take long adjust it for other systems. I also use cacoo a bit, never for schematics to be fair but it might work.

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answered 2016-10-07 15:45:57 -0500

updated 2016-10-07 17:33:32 -0500

I'm trying the online tool, which is FOSS and can save diagrams locally or to the cloud and has some useful built in shape libraries.

  • Floorplans
  • Proc. Eng.

Here's an example of an air-side system using some of the OpenStudio app images.

image description

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answered 2015-10-23 12:58:23 -0500

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This is what we use in eppy for the loop diagrams but it seems fairly limited. I haven't looked into it in detail though so perhaps it's worth developing further.

Jamie Bull's avatar Jamie Bull  ( 2016-10-10 05:01:30 -0500 )edit

answered 2015-10-23 11:52:36 -0500

If you literally just want to rough out layouts, I would think something like Visio or Dia might suit. I did a quick Google search and found HVAC templates for both.

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answered 2016-05-06 11:59:24 -0500

updated 2016-05-06 12:22:34 -0500

I just came across a template for Google Drawings, here.

It is limited but it could be a good alternative to quickly create and share schematics.

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Asked: 2015-10-23 07:45:00 -0500

Seen: 1,456 times

Last updated: Oct 07 '16