Hello,

I am having a problem with adiabatic floor setting. The model has only one exterior wall, while all the other surfaces should be adiabatic. However, the IDF file shows that the geometry is exported (5 adiabatic surfaces of which one of them has all Z coordinates 0). What confuses me is the warning I am getting in the errors output file:

** Warning ** No floor exists in Zone="DIVA PERIMETER ZONE", zone floor area is zero. All values for this zone that are entered per floor area will be zero.
** Warning ** CheckUsedConstructions: There are 27 nominally unused constructions in input.
** ~~~ ** For explicit details on each unused construction, use Output:Diagnostics,DisplayExtraWarnings;
** Warning ** GetInternalHeatGains: People="DIVA PERIMETER ZONE PEOPLE", specifies People per Zone Floor Area, but Zone Floor Area = 0. 0 People will result.
** Warning ** GetInternalHeatGains: ElectricEquipment="DIVA PERIMETER ZONE_PLUGMISC_EQUIP", specifies Watts per Zone Floor Area, but Zone Floor Area = 0. 0 Electric Equipment will result.

 

I have checked the tables, and indeed, there are no internal heat gains from the equipment and people. I am missing something here?

 

Thanks everyone for help!

 

Danijel

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Danijel,

 

Try flipping the floor surface in Rhino.  DIVA Thermal defines floors as downward-pointing surfaces (EnergyPlus wants all surface normals pointing outside the zone), so if your floor is point up, it won't find it.

 

Jon

Hi Jon,

The floor surface is pointing down and is in the ep_adiabatic layer in Rhino. When I open the IDF, the floor surface is described as 'wall'. I think that that is what makes the problem, because when I manually change it to 'floor' under the BuidlingSurfaceDetailed in IDF, I don't get any warning, and it works well.

The problem is that I need the graph and the image that are generated after running the simulation in rhino, and if I change it later in IDF editor, I won't be able to get them. 

Hope you can help!

Danijel

 

Sorry, Danijel.  I assumed the surface normal was at fault, but this sounds like a bug on our end.  Can you post your Rhino file so we can work it out?

 

Thanks,

 

Jon

Danijel Rusovan said:

Hi Jon,

The floor surface is pointing down and is in the ep_adiabatic layer in Rhino. When I open the IDF, the floor surface is described as 'wall'. I think that that is what makes the problem, because when I manually change it to 'floor' under the BuidlingSurfaceDetailed in IDF, I don't get any warning, and it works well.

The problem is that I need the graph and the image that are generated after running the simulation in rhino, and if I change it later in IDF editor, I won't be able to get them. 

Hope you can help!

Danijel

 

Sure Jon, no worries, it's in the attachment. Don't know, maybe I was doing something wrong, but don't think so. 

Hope we can fix it! I am also a bit confused about the 'construction materials' for adiabatic surfaces... can I apply same material for floor and walls? I know that there is no heat transfer between them, but can they still have same materials applied? Sounds a bit confusing, right? 

Thanks!

Danijel

Attachments:

Thanks, we'll take a look.

 

As for materials, the adiabatic surfaces don't exchange heat with the outside enviroment, but they do store and release heat within the zone.  So different materials can produce different results.

 

Jon

 


Danijel Rusovan said:

Sure Jon, no worries, it's in the attachment. Don't know, maybe I was doing something wrong, but don't think so. 

Hope we can fix it! I am also a bit confused about the 'construction materials' for adiabatic surfaces... can I apply same material for floor and walls? I know that there is no heat transfer between them, but can they still have same materials applied? Sounds a bit confusing, right? 

Thanks!

Danijel

Hi Danijel,

The floor area issue is something that has been fixed in the 2.0.0.8 version, or so we think. Are you using the latest version? It is listed as a beta on our website, but it is quite stable by now. On my computer, the floor area is calculated properly using your file.

There is another bug which sometimes causes the zone volume to be calculated incorrectly. We are shortly, in the next few days, releasing a version which fixes this and adds several advanced features to thermal simulations. 

Thanks,

Alstan

HI,

I have updated to the newest version, for now seems to run fine! I can see the heat gains that comes from the occupants! thanks! I will let you know if I find some new problems, but lets hope everything will work fine!

Thanks,

Danijel

Hi,

just add a short comment, in case someone has similar problem with the zone volume calculation...

As you said, I have noticed different volume calculations for same sized zones in different Rhino files. I have just moved the objects around in the model, reran the simulation few times, and got the object's position for which the volume is calculated properly. 

 

Regards,

Danijel

Thanks Danijel,

We're going to be releasing an update which fixes this problem early this week.

Alstan

Sorry but I didn't get it. I am trying to model a simple office with an adiabatic floor. If I assign it as an adiabatic surface energy plus recognizes it as a wall as already said above. So we are forced to have a floor element in our model but int his case it will exchange heat with the environment. Any ideas? The only thing that I can think is to something like 2 m insulation in order to minimize the heat losses from the floor.

Hi Kostas,

I just quickly looked at your file from the other thread. DIVA will assign floor area to any surface that is on the ep_floor layer OR has a downward facing surface normal. I think the issue in your case is that the floor surface faces inside the zone. Using the 'dir' command to flip it should help. 

Best,
Alstan

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