THERM 7.6.1.0 bad points at midpoints

[George Ostrow]

Using a Windows 7 Pro PC (yes, I know). Attached .thm file created by drawing pure rectangles in THERM snapping to a .dxf underlay. Should not be any bad points, overlaps, gaps. Able to assign materials, but that is as far as I got.

When I click BC to assign boundary conditions, I get the error messages attached. Examining the "bad" points they are only the midpoints of the rectangles. Never encountered before. How to get rid of them to proceed?

Have not used THERM in several years. So I may have made a mistake in the Options, attached?

[Robin Mitchell]

What version of THERM are you using?

--
You can view the THERM forum online at:
https://groups.google.com/g/LBNL-THERM
---
You received this message because you are subscribed to the Google Groups "THERM" group.
To unsubscribe from this group and stop receiving emails from it, send an email to LBNL-THERM+...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/5099a538-9582-4335-969f-6b2717aeda02n%40googlegroups.com.

[George Ostrow]

Subject line of my post says THERM 7.6.1.0

[Ventura, Ed Ramir]

There are several gaps in your model...

fixed the gaps and run my own boundaries just to see if it will run.

To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/20a70442-1b9f-4c57-b24c-c848b5f3300fn%40googlegroups.com.

[Robin Mitchell]

So it is ...

I ran this in THERM 7.7, as we don't really support 7.6 any more. But it showed the same issues. 

When running the boundary conditions, the program is putting a red line between polygons, which means there is a very small space between them which the program detects as a void

There is also a space surrounded by polygons that is not a polygon, ie, another void -- you have set the insulation color to white, so it is very hard to see the fact that the white space is not a polygon

It took a few tries, but I was able to delete and redraw the polygons that had small spaces between them, as well as filling the white void with a material. And then I was able to get the file to not have any issues. 

You should probably change your snap settings to snap to horizontal and vertical, so that you can draw rectangular polygons with straight sides -- the sides on your original drawing were not straight horizontally or vertically. 

I am attaching the file I fixed, but again, it's THERM 7.7, so you won't be able to open it with 7.6.

You might want to update to a more recent version of THERM. 

[George Ostrow]

Thanks for finding gaps. Wondering then if we don't have a snap to underlay setting correct?

[George Ostrow]

My first time on this forum but the level of help is amazing! I expected suggestions, but instead I am getting redrawing. Most grateful.

Still wondering if 7.6 cannot find the corner points of our perfectly orthogonal underlay? We always draw using AutoCAD and then trace over in THERM because THERM is a clunky drawing tool.

[Robin Mitchell]

When you are tracing, you can use the spacebar when you are near a point to have the line "snap" to that point. That generally helps with getting points to sit right on top of each other when you are drawing. 

You might want to look at this doc for some of the shortcuts -- spacebar to snap to a point is on the 2nd page. 

https://windows.lbl.gov/sites/default/files/software/THERM/THERM%207%20Toolbar%20Reference%20and%20Keyboard%20Shortcuts.pdf

Robin 

To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/84ba6979-ba43-4137-bc0c-62708402a0a4n%40googlegroups.com.

--

Robin Mitchell

Building Technology and Urban Systems Division
Energy Technologies Area
Lawrence Berkeley National Laboratory

[George Ostrow]

Spacebar trick acknowledged. But does snap just find ANY point along the side of a rectangle? Or does it find the true corner point? We want to draw rectangles by snapping to diagonally opposite underlay corner points.

[Robin Mitchell]

You have to get within half the distance of the cursor length and it will snap to the nearest point. 

To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/82123374-e407-4c9d-b148-a777b4f92746n%40googlegroups.com.

[George Ostrow]

Which I take to mean: snap does not find the one true corner point, just the nearest point to the cursor. Which in turn means gaps between adjacent rectangles are likely to creep in.

[Robin Mitchell]

You are right. But lots of simulators don't have any problems creating models that don't have gaps between adjacent rectangles, so possibly your method of working in THERM isn't ideal. 

To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/0f6cbb2e-a390-4500-a96c-b4cb34b0e850n%40googlegroups.com.

[Robin Mitchell]

If you are tracing an DXF, you can turn on snap to underlay, draw the polygon, an then possibly from there, when you are trying to match points, snap to the newly created polygon rather than the DXF.

To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/0f6cbb2e-a390-4500-a96c-b4cb34b0e850n%40googlegroups.com.

[Ventura, Ed Ramir]

I draw everything in AutoCad, save as R12 dxf and then use auto convert when importing the underlay. But you have to merge the points in auto cad before importing.

for example.

all layer 0, purge everything, and should be good.

To view this discussion on the web visit https://groups.google.com/d/msgid/LBNL-THERM/CACF39StHvUW9T_9Ut7nm7_NmYe1At%3DpECEkfX39hD%3Dq8WJYCVw%40mail.gmail.com.

[Ventura, Ed Ramir]

and these are closed polygons and not single lines. 

[George Ostrow]

My usual method is the same as yours: draw rectangles in AutoCAD, all layer 0, import as R12 .dxf.

The first time I tried AutoConvert it did not work. But now it does. Sigh. OK, closing this thread as resolved.

THANKS!