To GBS from Revit MEP with RAC Link

[jason.combs]

All,

I am attempting to develop appropriate output to GBS using Revit MEP. The Revit MEP project has spaces developed and are configured with base offsets and extend from first floor to second floor along with second floor to a level set above the peak of the roof.

I also have some spaces that do not have "hard" separations between them in order to be segregated by HVAC zones.

I am receiving errors when using the Revit-GBS client:


This gbXML file contains no roof surfaces. Running this file through GBS more then likely would produce meaningless results. If indeed, there is no roof surface, we suggest you add a very small roof (< 1 m2) and try again. If your BIM has roof surfaces, it is likely the room/zone objects are not in contact with it. Please ensure your room/zone objects are in contact with the surfaces above them.

Please be sure to review the GBS Revit Tutorial (http://www.greenbuildingstudio.com/downloads/RevitGBSTutorial.pdf) to determine how to check that your Revit Room objects are at the proper height.
Space id= sp-103-TRNG_STOR has no surfaces adjacent to it.
Space id= sp-108-FLIGHT_ATTENDANTS has no surfaces adjacent to it.
Space id= sp-115-VESTIBULE has no surfaces adjacent to it.
Space id= sp-116-TRAINING_ROOM has no surfaces adjacent to it.
Space id= sp-140-BOEING_WAREHOUSE has no surfaces adjacent to it.
Space id= sp-142-HAZARDOUS_STOR has no surfaces adjacent to it.
Space id= sp-148-CORRIDOR has no surfaces adjacent to it.
Space id= sp-149-ELEC has no surfaces adjacent to it.
Space id= sp-151-CLOSET has no surfaces adjacent to it.
Space id= sp-154-CONF has no surfaces adjacent to it.
Space id= sp-156-JANITOR has no surfaces adjacent to it.
Space id= sp-159-SPRINKLER has no surfaces adjacent to it.
Space id= sp-169-CORRIDOR has no surfaces adjacent to it.
Space id= sp-170-MENS has no surfaces adjacent to it.
Space id= sp-172-OPEN_OFFICE has no surfaces adjacent to it.
Space id= sp-211-MENS has no surfaces adjacent to it.
Space id= sp-250-ELEV has no surfaces adjacent to it.
The roof issue is leads me to believe that you cannot use a linked file to define the roof boundary. I don't have all zones defined and be default they are all lumped together.

The other issues lead me to believe that non-walled separations are not valid.

Can someone help and comment on this?

Regards,

[kyle.bernhardt]

Hey Jason,
What does the Shaded View of the Heating and Cooling Loads dialog look like for your Revit Model? Can you post a screen shot?

That first error I've seen happen when something else fails, I'm still getting up to speed on errors with GBS and I'll try and get one of those folks to take a peek. I know you can use linked Roofs, that should not be the issue.

As for the other errors, my testing has not shown that we display that error based upon using Space Separation Lines, so I'm not sure what's the cause, care to post your gbXML file?

Cheers,
Kyle B

[jeffh]

I would agree with Kyle. That first error I have seen many times submitting to GBS and the problemends up being something totally different.

You can also check to make sure the rooms or spaces on the upper most level have an offset that extends BEYOND the roof surface. Not extending beyond the roof surface can make the roof not be recognized.

I have also seen roof slabs with altered shapes cause failures. If you have any warped points on the slab you might want to try resetting the shape of the roof slab to see if it clears up the error.

[jason.combs]

Jeff and Kyle,

Thanks for the replies. I took a step back and rebuilt a coarse view of the model which included only the basics. I developed walls, windows, floors, doors, roofs, and rooms. From there I had no problems getting the GBS client to push to the cloud. However, from what I have learned the rooms are not properly defined in that the second floor rooms do not go about the roof and the first floor rooms do not go beyond the height of the ceiling. So, I adjusted the rooms repsective to their level and tried to run, but got errors that no roof exists. ??

Now, I am taking it a step further back and developing a one room building and checking the room element heights. I have received consistent results in that if I move the room upper limit above the roof to capture it, I get errors. If I set the room height to the ceiling height GBS runs.

Attached is the simple room file and gbXML file. Thanks in advance.

[thomas.olsson]

Jason,

looking at your sample Revit project, the setting for calculation of Volume Computations is not "on".

Having this checked, makes the "room volumes" look for upper and lower boundary elements. This can be the cause of your "no roof" message.

<Thomas>

[kyle.bernhardt]

Jason,
So I took a look at this for you this morning. Here are the notes I took as I looked at the model.

Looks like you are using Rooms, which in Revit MEP are not used for gbXML generation. You need to create Spaces in Revit MEP to be used as the basis for Analytical Model generation.
Volume Calculations were not turned on. This is useful when you want to visualize your Volumes in section views. Access this setting at Settings -> Area and Volume Computations... -> Computations Tab -> Areas and Volumes Radio Button.
I set up the "Ceiling" level ("Level 3" in your model, I changed it to "Level 1 Ceiling") to use a Explicitly define Volume Computation Height of 6". To do this I created a new Level Type and changed the Room Computation Height. From there I created a Space on the "Level 1 Ceiling" Level. This produced a "tight" Analytical Model in the Heating & Cooling Loads dialog (attached)

You still get the "Horizontal Area" error when you launch the GBS plugin from Revit, but there are valid results returned on the Web Service.I've attached my modified version of your example here, for your investigation. Does this feedback help with your larger issues on your original project? If not, I suggest you log a Support Request so we can look at the project file in question and diagnose.

In the interim, I would once again recommend that you try and troubleshoot your model using a Shaded view within the Heating and Cooling Loads dialog. This is basically a 1-to-1 visualization of the Analytical Modelthat is used for gbXML output.

Cheers,
Kyle B

[jason.combs]

Kyle,

Take a look at the results I have received from GBS. I looked at the aaaa-ADSK.rvt model as:

1. With no ceiling and one Room (I am using RAC in this case) extended beyond the roof.

2. With a ceiling and two Rooms where the attic space extend beyond the roof.

See the attached comparison. I receive almost double the energy costs when using the ceiling. This does not reflect your comment 4.

[marjorie.stein]

Hi Jason,
There appears to be an issue that we need to address with how GBS is handling the space above the ceiling. We are working to resolve this ASAP.
As an interim workaround I would recommend that you keep the ceiling, but define it as non room-bounding. And in addition set the upper limit of your conditioned space below the ceiling so that in includes the plenum area above. This will give you the correct floor area and the correct lighting, equipment, and occupancy loads. Unfortunately it will increase the volume of the project too. Like I said, we are working to correct this bug and apologize for the inconvenience.

Best, Marjorie