ThermalZone Volume

[RomainNouvel]

In the ADE Energy v0.5, the ThermalZone does not include a parameter volume.

In the case that a Building includes several ThermalZone (or if the ThermalZone does not correspond exactly to the 3D building geometry), information about the Abstract building volume and the ThermalZone floor area are not sufficient to calculate the space heating of the ThermalZone.

Therefore, a parameter volume is required for the ThermalZone.

[JoachimBenner]

I principally agree. In addition, I propose to introduce a [0..*]-relation between a ThermalZone and a CityGML Room. In LoD4 models, a ThermalZones quite often will coincide with a Room or a group of Rooms. The new relation will enable to calculate the volume size on base of the Room volume.

[RomainNouvel]

ok

[PRemmen]

+1:

defenitly needed

[RomainNouvel]

Since "volume" may refer to many different volumes (netto, brutto, including walls or not etc.), we should agree to a given volume definition. Since this "volume" parameter will be used for space heating/cooling calculation, we need to know the inner volume (volume of air) to be heated/cooled. Then, I would suggest to name more explicitly this parameter: "airVolume" or "innerVolume" with the following definition: volume bounded by the ThermalZone, with exclusion of bounding walls, floors and ceiling.

[JoachimBenner]

I am not sure that it is a good idea to concentrate on the "airVolume" alone.

(1) This geometry cannot be derived from an LoD2 or LoD3 model, because no information on interior walls or the thickness of the outer walls is available. Thus, this concept would either need a LoD4 model, or the availability of additional information on the interior structure of the building, e.g. an IFC model.

(2) In gbXML, the zone volume is just the sum of the volumes of the space which belong to this zone. For interior walls, space boundaries lie in the middle of the wall, and for exterior walls at the exterior side. Thus, the zone volume in gbXML is not the inner volume, but the gross volume including walls.

[RomainNouvel]

Ok for (1) What you describe in (2) is the ThermalZone grossVolume as far as I have understood.

Then, you suggest to store instead a parameter "grossVolume" in the ThermalZone class, that we could use to assess the air volume required for the space heating demand calculation. Is that right?

[JoachimBenner]

Yes, but why not using both values (netVolume and grossVolume) as optional parameters?

[RomainNouvel]

Looks good! Here would be the definitions (adpated from this online glossary: http://www.new-learn.info/packages/euleb/en/glossary/index3.html )

• netVolume: Volume of the air space of a ThermalZone.
• grossVolume: Volume of a ThermalZone measured by its external dimensions. These external dimensions lies on the outside face of exterior boundaries (e.g. wall, roof) and at the middle of boudaries shared by several ThermalZone (e.g. sharedWall, intermediary floor), so that the sum of the Building ThermalZone grossVolume equals the Building grossVolume.