[TRNSYS-users] Active Wall Layer: Number of loops and Autosegmentation

David Bradley bradley at tess-inc.com
Wed Jul 1 07:25:22 PDT 2009


Marshall,
 Usually the way radiant floors are set up is that there is a manifold 
from which a number of parallel flow loops depart. The "looping back and 
forth" (ie the path of a given piping loop through the floor) is built 
into the model's algorithms. In setting up the floor, you specified a 
pipe to pipe distance and in setting up the floor, you specified an 
area. In order to figure out how long each pipe is, the model needs to 
know how many parallel loops there are. There is an equation in the 
06-Multizone Building manual that shows how you can calculate the number 
of loops from the floor area, pipe length, and pipe-to-pipe distance.

  I think in the example that you give, you'd have a single fluid inlet 
and 2 loops. The 25 times doesn't matter to the model. Segmentation is 
only necessary in order to keep the specific mass flow rate of liquid 
high enough to be in the range of the model.

Kind regards,
 David


Marshall L Sweet/sweetml/O/VCU wrote:
> TRNSYS users,
>
> Does anyone know what the actual physical meaning of "number of fluid 
> loops" when defining and active layer? 
>
> If I want to model a radiant heated floor that had 1 fluid input but 
> that input looped back and forth 25 times in a zone, would the number 
> of loops then be 25?
>
> What if I had a zone that had two fluid inputs and both inputs looped 
> back and forth 25 times each?
>
> Also I have been unable to get the autosegmentation feature to put my 
> floor in segments.  When I click the "DO" button it still says no 
> segmentation, is this because maybe my zones are small enough that 
> they don't need segmented or is something wrong? 
>
>
> Thanks,
>
> Marshall
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>
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