Question for the developers: mesh tiles in space

[Gus Smedstad]

Something I've been wondering about for a while.

Mesh tiles in space have several behaviors that don't seem to be consistent with the rest of the game or intentional. But I could be wrong. I'd like to know if they're "working as intended," or if this these are just loopholes that might get closed someday.

Mesh tiles block light, but they don't block sunlight. They're actually better than windows, which is not intuitive.

Mesh tiles don't block scanners, even though everything else that's solid does. This seems related to the sunlight issue.

Mesh tiles are perfect insulators in space, behaving like a vacuum. You'd think they'd behave like metal pipes. That is, they exchange heat with adjacent tiles, and exchange heat with their contents (liquid or gas). Instead they effectively don't exist thermally, and only the gas, liquid, or vacuum matters.

Are all of these behaviors intended? Or are they oversights?

 

[Neotuck]

Hope this get's an answer, I would like to know too

[Sasza22]

I`m pretty sure none of this is intended.They used to let lamp light through as well as decor. Now they don`t. Sunlight seems to be an oversight (a one hard to believe how long it`s in).

The heat transfer looks like they wantd to cut a corner and just leave it to the gas inside to prevent double calculations and more heat transfer than intended. It gets a problem in vacuum where ther is suddenly no heat transfer at all. It needs a special case or a complex fix. Maybe they are working on one that adresses all the issues at once so we have a half baked system currently.

[riwenna]

On 23/04/2019 at 2:11 AM, Gus Smedstad said:

Mesh tiles are perfect insulators in space, behaving like a vacuum. You'd think they'd behave like metal pipes. That is, they exchange heat with adjacent tiles, and exchange heat with their contents (liquid or gas). Instead they effectively don't exist thermally, and only the gas, liquid, or vacuum matters.

I've only recently found/realized that mesh tiles behaven as whatever material is "filling" them.

But, in general, mesh tiles (hm, ok, and airflow tiles, and doors, and also um... paintings and scluptures, and all the buildings) are the only mechanic in the game that allows us to place two elements on the same tile (one element from the metal tile itself + gas/liquid that is in the tile). Therefore, I see three different options for their thermal conductivity:
a) Ignore the material filling them and go with pure metal tile properties.
b) Ignore the mesh tile properties and go with the properties of the filling material
c) Combine the properties of the metal tile and the material filling them

The possible results of those options, as I see them:

a) Ignore the filling material
- mesh tiles become metal tiles which allow air and liquid flow
- super-conductive air chambers? One could build a set-up to hear or cool CO2 or Chlorine efficiently using mesh tiles as a cheaper alternative to tempshift plates. It would also allow us manipulating the "heat storage" capacity of gas chambers; increasing it for unpressurized gas chambers (Hydrogen SHC of 2.4 (DTU/g)/*C sitting at 2Kg/tile can store less energy than Gold mesh tile with SCH 0.150 (DTU/g)/*C at 100Kg/tile --> a room full of Hyrdrogen at 2Kg/tile but covered in mesh in this variant would act like a room full of Hydrogen at ~6.25Kg/tile with no mesh tiles; but covering a room with more than 6.25Kg/tile of Hydrogen with mesh tiles will start reducing the heat capacity of each tile)
- increasing conductivity and massively reducing the specific heat capacity in liquids (similar calculations to above, except H2O sits at 1000Kg/tile. We get 0.150 (DTU/g)/*C for 100Kg of mesh tile compared to 4.179 (DTU/g)/*C for 1000Kg/tile of water, in which case that water-filled metal tile acts equivalently to a plain tile of ~3.59 Kg of H2O). This would again likely allow for much more efficient water cooling systems, where you'd effectively have to spend ~279 times less energy to heat up a pool of water

b) Ignore the mesh tile itself
- this is how it currently works

c) Combine the properties of mesh tile material and the filling material
- i started typing a different explanation here, but I just realized I actually don't know how exactly the heat exchange of gasses/liquids and the surrounding buildings works. Do they act like two separate entities in the same tile and exchange heat accordingly?
- if the answer to the above is "yes", then mesh tiles could work in a similar way. They exchange the heat with their adjacent tiles based on their properties, and so does the gas/liquid that fills them. Additionally, they also exchange heat with the material filling them following the same rules of exchange that is applied to buildings and decore items.
- an alternative could be that they act as a "single element" tile, somehow combining the properties of the mesh tile and the filling material. I don't think there is any heat interaction in the game that relies on the properties of more than two elements (i.e. two adjacent tiles). However, if this was done by weighted averaging the element properties weighted by their mass, the effects would be that mesh tiles+gas work very similarly to pure metal tiles (as we will be combining between 2-20KG/tile of gas, and 100KG of metal for the mesh), and mesh tiles+liquid work close to liquid (as we are now combining ~1000kg/tile of liquid + 100kg of metal) except that the thermal conductivity of the liquid is slightly increased. I personally don't think this will happen in any form as it introduces a completely new type of element interaction and allows the player (to some extent) to "build" a material with properties not available in the game.

The question got me thinking so I tried a bit of analysis Hope my maths holds water at least to some extent. I'd be happy if somebody corrected my assumptions if they spotted any holes in them.

At least for me personally, after trying to analyse the effects of each of the two possible options for change (as far as I can see), it seems like they would introduce some very inconsistent behaviours as well. So my assumption is that (at least sa far as the heat-conducting properties go) the mesh tiles will not change.

I can't speak to the light/sunlight issue, but that one does seem a bit odd to me as well.

Oh and BTW, how exactly does the heat exchange work when there's a building + gas/liquid + surrounding tiles (e.g. flooring or undug tiles)?

[Gus Smedstad]

2 hours ago, riwenna said:

 I actually don't know how exactly the heat exchange of gasses/liquids and the surrounding buildings works. Do they act like two separate entities in the same tile and exchange heat accordingly?

They do. In fact, there can be several layers in one square.

Pipes - both gas and liquid pipes - exchange heat with their contents, and then exchange heat with the gas or liquid in the square, or the tile if it's they are inside a solid tile.  The gas or liquid in the square then exchanges heat with any buildings in the square. Oh, and with any tempshift plate in the square.

For example, you could have a gas pipe with hydrogen, a liquid pipe with water, oxygen in the square, and a generator in the square. The exchanges are hydrogen pipe <--> pipe, water <-> pipe, gas pipe <-> oxygen, liquid pipe <-> oxygen, and oxygen <-> generator.

Buildings don't exchange heat with anything but the gas or liquid in the square. They do not, for example, exchange heat directly with pipes, tempshift plates, or adjacent objects. This is why you can't cool robominers in a vacuum with pipes.

Solid tiles exchange heat with pipes, and adjacent solid, liquid, or gas tiles, and any adjacent tempshift plates.

Mesh tiles don't. They behave pretty much like buildings, only exchanging heat with the liquid or gas in that square, and nothing adjacent.

[pacovf]

23 minutes ago, Gus Smedstad said:

Buildings don't exchange heat with anything but the gas or liquid in the square. They do not, for example, exchange heat directly with pipes, tempshift plates, or adjacent objects. This is why you can't cool robominers in a vacuum with pipes.

I've made a suggestion about this already, but I would love if buildings exchanged heat directly with radiant pipes. Cooling buildings in space is harder than it needs to be right now, IMO.

[mathmanican]

On 4/22/2019 at 7:11 PM, Gus Smedstad said:

Mesh tiles are perfect insulators in space, behaving like a vacuum. You'd think they'd behave like metal pipes. That is, they exchange heat with adjacent tiles, and exchange heat with their contents (liquid or gas). Instead they effectively don't exist thermally, and only the gas, liquid, or vacuum matters.

I'd like to add a slightly different take on this, based on recent testing, and experiments done in the past. Both mesh and airflow tiles behave thermally like debris. They interact with the tile BELOW them, and exchange heat with that tile. So they are not perfect insulators with things below them.

On 4/24/2019 at 10:17 AM, Gus Smedstad said:

Mesh tiles don't. They behave pretty much like buildings, only exchanging heat with the liquid or gas in that square, and nothing adjacent.

It is true that they do not exchange heat with tiles to the side or above, but they do exchange heat with tiles below. This is like debris, not buildings. 

The exchange rate is the same rate as the same mass of mined matter sitting as debris. This is true in vacuum, gas, and liquid environments. Heat transfer to surrounding medium, and to the tile below, matches the heat transfer of debris. To me, this suggests the code treats the 100kg metal from the mesh/airflow tile as if it were debris, for heat calculations. It's subtly different than buildings, which can help with planning builds later on. Consider the images below. 

• In the first image, in a vacuum, the debris and mesh tile transfer heat at exactly the same rate to the tile below. The solid tile of metal transfers heat much faster, while the mesh tile maintains perfect temp. 
• In the second image, hydrogen gas enters the picture. The two setups transfer heat to the tile below at almost the same rate. I say almost because my initial temps of two two metals were 1738.9K and 1739K. Some very interesting turbulent up/down changes of gas temp on both sides that cause the two sides to cycle between which transfers heat faster. The cyclic behavior suggests some numerical scheme is at play (high deltaT clamping because of the multiply by 25 gas/solid interacion). However, the average behavior suggested the two really do transfer heat at the same rate. 
• In the third image, the liquid water stabilized the turbulent temp changes, and the two pictures transfer heat at the exact same rate. 

In summary, think of mesh and airflow tiles as debris for heat transfer computations. Whether this is intended behavior or not, that's another question.  

One fun side effect of this fact is that you can rapidly alter the temperature of an insulated tile by building a mesh or airflow tile ABOVE it. I ran into this issue quite a bit with the old steam turbine, and for a while I wondered why some of my insulated ceramic tiles would stay at 20C, while others would reach >150C. The issue was always either (1) metal debris above the hot insulated tile or (2) a mesh or airflow tile above the hot insulated tile. This fact can be used to both heat and cool insulated tiles rapidly. Coupled with running  debris through an insulated tile on conveyors, you can watch insulated ceramic behave like regular obsidian (hyperbole).