[TRNSYS-users] Floor Heating - Trnsys3D

Thu Apr 30 13:26:00 PDT 2020

Dear David,

Regarding my previous email,

#1) When I switch to "manual mode" and click on "Divide Surface" button, it doesn't segment the floor and again gives one segment for the whole floor (The attached image).

I also realized that it is possible to change the minimum allowable flow rate by changing pipe spacing. But as it should be according to the standards, I cant change it that much. Is there any other way to resolve this problem?

Thank you in advance.

Best regards
Hoofar

________________________________
Von: Hemmatabady, Hoofar
Gesendet: Dienstag, 24. März 2020 11:00:04
An: David BRADLEY
Betreff: AW: [TRNSYS-users] Floor Heating - Trnsys3D

Dear David,

Thank you for your reply.

#1) When I switch to "manual mode" and click on "Divide Surface" button, it doesn't segment the floor and again gives one segment for the whole floor (The attached picture, ManualMode).

#3) What is the surf-ID definition order in TRNbuild?  e.g., for the zone first floor (The attached picture, surf-ID), which is heated by the active layer with the construction type "ADJ_CEILING_basement",  should I give the fluid inlet temperature and flow rate from simulation studio to the surf-ID 44 and then give the output from 44 to 46 and from 46 to 47 and....?

Best regards

Hoofar

________________________________
Von: David BRADLEY <d.bradley at tess-inc.com>
Gesendet: Montag, 23. März 2020 13:43:23
An: TRNSYS users mailing list at OneBuilding.org
Cc: Hemmatabady, Hoofar
Betreff: Re: [TRNSYS-users] Floor Heating - Trnsys3D

Hoofar,

  If you click on the "Geometry Modes" button in a given zone you can switch one or more zones to "manual mode." This allows you to create the geometry in Trnsys3d but then autosegment the floors of a particular zone afterwards. The disadvantage, of course, is that once you switch a zone to manual mode you cannot then go back and edit the building geometry in Trnsys3D.

  If you do not want to switch to manual mode then here are some responses to your questions:

1) How should be the surfaces split in Trnsys3D? Have I used the right approach?

I believe that what you've done is reasonable. The autosegment feature puts a number of smaller floor areas in series.

2) How can they be manually connected?  (when the Autosegmentation is done, surfaces are automatically connected in series with automatic inlet temperature and the same inlet flow rate)

I think you will need to do this by adding outputs and inputs to your Type56 model. The connections will need to be done outside of Type56 in the Simulation Studio.

3) After splitting the floors, which output shows the overall heat transfer to the zone and which one shows the final outlet fluid temperature?

I think that for the overall heat transfer to the zone you'll need to sum up a number of Type556 outputs. The overall heat transfer to the zone will be the sum of the heat transfer to the zone from each individual floor piece. The final outlet temperature will depend upon the order in which you connect the floors to one another in the Simulation Studio. I'd suggest using the surface IDs that TRNBuild assigns and drawing a picture so that you can keep all the connections straight.

4) What should be the standard number of fluid loops per square meter?

There is an equation in the TRNBuild/Type56 manual that suggests a way of computing the number of loops based on how long you want each individual pipe to be.

kind regards,
 David

On 03/21/2020 11:38, Hemmatabady, Hoofar via TRNSYS-users wrote:
Hello,

I am working on a project on heating a house with a heat pump. I designed a Trnsys3D model of the house, which I need to implement a floor heating system on it. After adding an active layer in TRNbuild, got the error "Specific fluid mass flow of active layer in surface  16 below minimum value of 2.96 kg/m2h Please, increase the minimum mass flow rate or use the autosegmentation feature of TRNBuild for subdividing the surface.".

As I have a 3d model, the Autosegmentation is not possible. Therefore, following TRNbuild documentation "For airnodes with 3D geometric information the splitting of surfaces have to be done in Trnsys3D and then manually connected",  I split my floors (in Sketchup) into 20 equal surfaces using parallel lines and imported my 3d model back to TRNbuild.

Here are my questions:

1) How should be the surfaces split in Trnsys3D? Have I used the right approach?
2) How can they be manually connected?  (when the Autosegmentation is done, surfaces are automatically connected in series with automatic inlet temperature and the same inlet flow rate)
3) After splitting the floors, which output shows the overall heat transfer to the zone and which one shows the final outlet fluid temperature?
4) What should be the standard number of fluid loops per square meter?

Best regards
Hoofar Hemmatabady

_______________________________________________
TRNSYS-users mailing list
TRNSYS-users at lists.onebuilding.org<mailto:TRNSYS-users at lists.onebuilding.org>
http://lists.onebuilding.org/listinfo.cgi/trnsys-users-onebuilding.org

--
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
3 North Pinckney Street - suite 202
Madison, WI  53703 USA

P:+1.608.274.2577
F:+1.608.278.1475
d.bradley at tess-inc.com<mailto:d.bradley at tess-inc.com>

http://www.tess-inc.com
http://www.trnsys.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20200430/53027068/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: untitled.png
Type: image/png
Size: 277771 bytes
Desc: untitled.png
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20200430/53027068/attachment-0001.png>