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Extended Slabs?

Posted: Mon Jun 16, 2014 5:13 pm
by dnelson
Hello,

I'm trying to model a building that has extended concrete slabs and column projections on each floor where a renovation recently occurred.

Originally, the extended slabs and column projections were uninsulated. Now the exterior walls have been moved out and the extended slabs and column projections are insulated. The picture below explains things more clearly.

I'm wondering how these extensions and projections can be modeled so they transfer heat into and out of the building both before and after the renovation. (uninsulated before and insulated after). Is it possible, any ideas?

Thanks for any help.
Dave

Image

Re: Extended Slabs?

Posted: Mon Aug 25, 2014 7:52 pm
by Megan
Dave,

Since you want to capture the thermal properties of these projections, you'll need to draw them as rooms in the model. You will want them to be as thin/flat as possible (so they have little to no volume). These spaces will be set as unconditioned in your model.

The appendix in the ApHVAC User Guide for modeling hydronic systems describes a similar process for modeling Radiant Slabs.

I recommend drawing only the parts of the columns/slabs that project. Create the rest of the building as if these projections were not there. The projections will have dimension that the planar floors/walls of the rooms do not, so align them to the centerline. Internal constructions in the VE are applied to the centerline of the geometry.

Lastly, when you assign constructions to your conditioned spaces, you'll have parts of your wall show up as internal instead of external. You'll need copies of your external constructions to be internal so you can assign them appropriately.

Thanks,
Megan

Re: Extended Slabs?

Posted: Fri Oct 31, 2014 2:59 pm
by dnelson
Thanks Megan, that seemed to work.