Introduce Area and Thickness for Heat transfer

[Shurlan]

Let's start with the reason I want additional object attributes:

I want to build something that involves heat transfer. (Let it be cooling the bases water, crude oil -> natural gas, or whatever else) Since the game uses scientific values (specific heat capacity, thermal conductivity) which are close to their real life counterparts (well... mostly. looking at you hydrogen). I expect the transfer of thermal energy to somewhat follow the simplified rule of "q = tc * A * l * dT * t"

• q: energy transferred
• tc: the thermal conductivity of the medium
• A: the area of the cross section of the medium (perpendicular to heat flow)
• l: the length/thickness of the medium (parallel to heat flow)
• dT: temperature difference
• t: time

In-game however we have buildings that behave as if they have a fifth of their actual mass regarding heat capacity. For pipes the thermal conductivities of the pipe material and content/outside apparently gets averaged instead of using the lowest number the inverse average (in real life terms I don't even know where to start with this one) and insulated/radiant pipes do who knows what (it doesn't say anywhere). All because, presumably, otherwise the observed heat transfer in the game seems to slow. But instead of the above botch one could simply stop assuming an area of 1m² and thickness of 1m for everything.

Giving every structure reasonable values for area and thickness also would make balancing easier (more values to fudge).

Machinery can't dissipate heat quickly enough: Instead of mass-fudging give it a bigger area.
Pipes barely interact with the environment: Make them not 1m thick.
The property of insulated/radiant pipes is [redacted]: a lot thicker, has a big area.

Since everyone shares the real life expirience of "q = tc * A * l * dT * t" the result automaticly will feel reasonable.

Impact on game performance: None. Upon construction the properties can be multiplied together, stored and thereafter used instead of tc.

Side note: Since every object in the game has it's own temperature and is not just a medium between two objects, half of the objects average thickness should be used for calculating the heat transfered, such that heat flows from core to core and not from one side to the other.

Edit: Factual corrections thanks to a comment by Abt9

[Yunru]

First: 

1 hour ago, Shurlan said:

For pipes the thermal conductivities of the pipe material and content/outside apparently gets averaged instead of using the lowest number (in real life terms I don't even know where to start with this one)

Which is consistent with every other non-insulated material in game.

Second: 

Quote

and insulated/radiant pipes do who knows what (it doesn't say anywhere)

It uses the lower value, for any insulated item.

Third:

Quote

Since everyone shares the real life expirience of "q = tc * A * l * dT * t" the result automaticly will feel reasonable.

Impact on game performance: None. Upon construction the properties can be multiplied together, stored and thereafter used instead of tc.

Side note: Since every object in the game has it's own temperature and is not just a medium between two objects, half of the objects average thickness should be used for calculating the heat transfered, such that heat flows from core to core and not from one side to the other.

None of this is necessary. No-one "shares the real life expirience of [snip]", they share the real life experience of "hot things get colder making cold things hotter" and "insulated does this slower" so the result already feels reasonable.

 

TL;DR: It's all just unnecessary calculations to add for no gain.

Also, area is already a thing, that's how temp-shift plates work.

[D.L.S.]

You aware that pipes and wires in game dont conduct heat along itself, i mean if you heating one side of few tiles long empty pipe in vacuum - other side wont get heated. i think this need fix too.

As for pipe which exchange temperature with tile: tile size 1x1m so pipe length 1m, game assuming that area of pipe 1m^2, so pipe with such length must have circumference 1m to have 1m^2 wall area, so it would be ~ 0.32m diameter pipe, pipe in game visually looks about this size(+/-). So in this particular case i dont see big issue that game always assume pipe area as 1m^2. For solid tiles area of contact also should be ~1m^2 on macroscale, on microscale it is not so simple, but we dealing with game world where quanta of length(plank distance?) is 1m...

Buildings i think should have "surface area" parameter. We have mass and material(so we can get its density), having mass and density we can calculate volume of building, but we know nothing about building shape so cant calculate surface area, we need it as addition parameter. and having surface area you can calculate heat exchange of building and surrounding it fluid.

Btw Helium heat capacity also broken.

[Oofle]

I think that this would add a lot of complexity to the game that we don't really need.

[Shurlan]

2 hours ago, Yunru said:

Which is consistent with every other non-insulated material in game.

But heat transfer over all is not. We have 4 different behaviors for 1 system: averaging, smallest tc, fitfh of heat capacity and no transfer whatsoever. Non of it explained anywhere (when does what happen) but all supposedly governed by the same values.

 

2 hours ago, Yunru said:

It uses the lower value, for any insulated item.

Which does not change the fact that averaging the thermal conductivity in the other cases is nonsensical and has no counterpart in physics. Stop proclaiming the crutch as a leg.

 

2 hours ago, Yunru said:

None of this is necessary. No-one "shares the real life expirience of [snip]", they share the real life experience of "hot things get colder making cold things hotter" and "insulated does this slower" so the result already feels reasonable.

The problem is the rate at which heat flows and the current state of the game feels not reasonable at all to me. If I touch a radiator I don't have to worry about dying in seconds due to my core temperature rising to 45°C.

2 hours ago, Yunru said:

No-one "shares the real life expirience of [snip]"

I was not aware that the internet spreads across different universes. Joke aside, I didn't mean that everyone in their experience of the world thinks about this formular when it comes to things hot and cold, but that applying it to the game will feel right in the same way fudging can, but in a way that is consistend.

Regarding insulators: If I grab a piece of copper and a marker and write "Insulator" on it doesn't become on. Insolators are insolators not because they say so but because the have low thermal conductivity.

2 hours ago, Yunru said:

TL;DR: It's all just unnecessary calculations to add for no gain.

Also, area is already a thing, that's how temp-shift plates work.

No additional calculations would be made, they would just change. If you did not look at them before, no one is going to force you to in the future.

[Yunru]

4 minutes ago, Shurlan said:

Which does not change the fact that averaging the thermal conductivity in the other cases is nonsensical and has no counterpart in physics. Stop proclaiming the crutch as a leg.

The problem is the rate at which heat flows and the current state of the game feels not reasonable at all to me. If I touch a radiator I don't have to worry about dying in seconds due to my core temperature rising to 45°C.

Regarding insulators: If I grab a piece of copper and a marker and write "Insulator" on it doesn't become on. Insolators are insolators not because they say so but because the have low thermal conductivity.

I'd like to introduce you to two concepts. They're known as "game" and "abstraction"

[Shurlan]

2 hours ago, D.L.S. said:

As for pipe which exchange temperature with tile: tile size 1x1m so pipe length 1m, game assuming that area of pipe 1m^2, so pipe with such length must have circumference 1m to have 1m^2 wall area, so it would be ~ 0.32m diameter pipe, pipe in game visually looks about this size(+/-). So in this particular case i dont see big issue that game always assume pipe area as 1m^2. For solid tiles area of contact also should be ~1m^2 on macroscale

The point of introducing and changing the current game are not the parts where it works but the ones where it doesn't.

2 hours ago, D.L.S. said:

but we dealing with game world where quanta of length(plank distance?) is 1m...

No, it being a grid of 1m does not make 1m the planck distance of the game.

2 hours ago, D.L.S. said:

having mass and density we can calculate volume of building, but we know nothing about building shape so cant calculate surface area, we need it as addition parameter. and having surface area you can calculate heat exchange of building and surrounding it fluid.

Btw Helium heat capacity also broken.

Precisely my reasoning. The simulation lacks information in this regard.

[Yunru]

2 minutes ago, Shurlan said:

No, it being a grid of 1m does not make 1m the planck distance of the game.

Yes it does? In regards to being the smallest measurable distance at least.

[Shurlan]

9 minutes ago, Yunru said:

I'd like to introduce you to two concepts. They're known as "game" and "abstraction"

Its hard to abstract any further than it adhering to one formula.

Inconsistency is the enemy of a nice gaming experience, at least for me... I hate it. But I get yout point of probably taking it to far. In my eyes they used different values for different materials and drive it by a physics model, kinda, with the kinda being annoying.

[Sasza22]

8 minutes ago, Shurlan said:

But heat transfer over all is not. We have 4 different behaviors for 1 system: averaging, smallest tc, fitfh of heat capacity and no transfer whatsoever. Non of it explained anywhere (when does what happen) but all supposedly governed by the same values.

I can agree that some of the interactions are non obvious. like heat transfer between solid tiles is much slower than between solids and gasses. I`d like to have the rules esplained somewhere. But for my needs insulated tiles transfering heat much slower is enough. Most people won`t dive too deep in the calculations and adding an extra "thickness" stat won`t tell them anything useful.

 

11 minutes ago, Shurlan said:

Which does not change the fact that averaging the thermal conductivity in the other cases is nonsensical and has no counterpart in physics.

Afaik the system uses a log average. I`m not sure about real life calculations but for a simplified simulation it works. Heat transfers the proper way and it happens faster for better heat conductors.

 

14 minutes ago, Shurlan said:

The problem is the rate at which heat flows and the current state of the game feels not reasonable at all to me. If I touch a radiator I don't have to worry about dying in seconds due to my core temperature rising to 45°C.

The game time is not realisitc. Heat transfer happens in a rate that matters but is managable. That said i had dupes get hypothermia in contact with 20^oC hydrogen which sounds weird but lets assume dupes aren`t real human and their metabolism is pretty wierd.

 

15 minutes ago, Shurlan said:

Regarding insulators: If I grab a piece of copper and a marker and write "Insulator" on it doesn't become on. Insolators are insolators not because they say so but because the have low thermal conductivity.

Now lets imagine making something a`la copper fibre. It would be 100% copper but shaped in tiny hair like strings. Lets make wall insulation out of it. Most of the insulation will be air trapped between the copper providing pretty nice insulation but overall it would be inferior to proper insulators.

It`s the smae thing in game. you can use rock as insulation not beacause it`s properties but beacause how it is shaped. Th game simulates it by useing the lower heat transfer. It`s not 100% accurate (sometimes not even 50%) but for a simulation it works.

20 minutes ago, Shurlan said:

No additional calculations would be made, they would just change. If you did not look at them before, no one is going to force you to in the future.

So what is the point of the change then? The current system is pretty balanced. We risk unbalancing it. What is the benefit?

[Shurlan]

2 minutes ago, Yunru said:

Yes it does? In regards to being the smallest measurable distance at least.

Dupes can be different distances apart than 1m, which goes for other lose objects.

[Yunru]

1 minute ago, Shurlan said:

Dupes can be different distances apart than 1m, which goes for other lose objects.

Nope. Mechanically they occupy the whole two tiles.

[Shurlan]

52 minutes ago, Oofle said:

I think that this would add a lot of complexity to the game that we don't really need.

The system is already there. Arguably it being four cases increases complexity.

1 minute ago, Yunru said:

Nope. Mechanically they occupy the whole two tiles.

You are right. However clothing has non integer meter thickness and is used in the simulation for heat transfer. Making me kind of right in the probably most pointless way.

[Shurlan]

9 minutes ago, Sasza22 said:

I`d like to have the rules esplained somewhere.

Me too. If anything this is the bare minimum.

10 minutes ago, Sasza22 said:

But for my needs insulated tiles transfering heat much slower is enough. Most people won`t dive too deep in the calculations and adding an extra "thickness" stat won`t tell them anything useful

Sure, but since the behavior doesn't change why not add it for those who do care.

11 minutes ago, Sasza22 said:

Afaik the system uses a log average. I`m not sure about real life calculations but for a simplified simulation it works. Heat transfers the proper way and it happens faster for better heat conductors.

It really starts to break down for Insulation which basically should conduct no heat (given its thermal conductivity) but does if you build pipes, where it can matter a lot. Also if they calculate a logarithmic mean for most of the heat transfer in the game, it is all the more reason to do it properly since computationaly logs can be expensive and already rewuire branched execution for edge cases. So I would claim that the simplification actually runs slower than doing it properly would.

25 minutes ago, Sasza22 said:

The game time is not realisitc. Heat transfer happens in a rate that matters but is managable. That said i had dupes get hypothermia in contact with 20^oC hydrogen which sounds weird but lets assume dupes aren`t real human and their metabolism is pretty wierd.

This actually is quite realistic. Hydrogen has about 7 times the thermal conductivity of air. So 20°C hydrogen would feel like -80°C Air. (Except air moisture and convection would play a bigger role than actual heat transfer)

39 minutes ago, Sasza22 said:

Now lets imagine making something a`la copper fibre. It would be 100% copper but shaped in tiny hair like strings. Lets make wall insulation out of it. Most of the insulation will be air trapped between the copper providing pretty nice insulation but overall it would be inferior to proper insulators.

What you describe is that the area through which the heat inside the copper travels is reduced. (Area being the cross section along the patch from one side to the other and not surface) and since the fibers are not straight from one side to the other the length/thickness increases. I meant my comment litteral.

46 minutes ago, Sasza22 said:

So what is the point of the change then?

I don't understand what you mean. Changing the current system instead of adding to the old system does not keep the status quo.

50 minutes ago, Sasza22 said:

The current system is pretty balanced.

I disagree otherwise I would not bother making this thread. In my eyes I suggest an improvment for gamplay (planning out contraptions) and apparently performance (since they currently compute a s*** load of logs).

54 minutes ago, Sasza22 said:

We risk unbalancing it.

That is the devs decision not yours or mine. The Devs can say what they think on their own .

You are right in that I probably should have made this post half a year ago and not a month before release but I was complacent in hoping "It's early access, they'll fix it soon", soon never was to be.

58 minutes ago, Sasza22 said:

What is the benefit?

I don't feel the need to repeat myself. If the benefit is not apparent for you then there is nothing to argue about, since it would appear that your play style is unrelated to what I propose. I would just ask to not conflate "of no use to me" with "irrelevant for everyone".

[Abt9]

Sorry, uh, do you even physics? It seems like your 'real-life formulae' is out of nowhere, which isn't really making sense.

In real life, if two material touch with the identical thickness the combined conductivity is inverse average. When they are placed in parallel, then it is simple average. Logarithmic average lies in between these two, which is thus a reasonable choice. But minimum is minimal... So I don't get where the hypothetical minimum is from - unless it's by design like insulated tiles in the game.

Also heat transfer simulation isn't quite easy, so it's not so feasible ti go for full realism. We need some compromise, and this game made a good one imo.

[Shurlan]

8 hours ago, Abt9 said:

Sorry, uh, do you even physics? It seems like your 'real-life formulae' is out of nowhere, which isn't really making sense.

Apparently not in a sufficiemt manner. The formula comes from heat conducted through a medium and for the same medium is correct, however so is your critisism that for different media their heat resistance is additive. I confess to not reading up properly.

8 hours ago, Abt9 said:

So I don't get where the hypothetical minimum is from

 

8 hours ago, Abt9 said:

In real life, if two material touch with the identical thickness the combined conductivity is inverse average.

To be honest: From the in-game tooltip on thermal conductivity (which wants me to make them do it properly even more), I stand corrected, thank you for that. The fact that in my proposed system the medium with the lower thermal conductivity offers no resistance to heat flow should have tipped me off, but hindsight is 20 20. I'll change my original suggestion accordingly.

8 hours ago, Abt9 said:

Also heat transfer simulation isn't quite easy, so it's not so feasible ti go for full realism.

Indeed, my assumption/simplification is, that thermal energy is stored in the middle of an object and therefore flows from middle to middle, at least for apparently solid objects. For pipes and similar I would go for the middle between the inside and outside surrounding. I find this to be reasonable.

8 hours ago, Abt9 said:

When they are placed in parallel, then it is simple average.

An alternative way is to calculate it separately for both media and then sum it up. Which the game already does since every tile gets computed separately. With your argument in mind I would state that the game overdoes the parallel flow.

8 hours ago, Abt9 said:

Logarithmic average lies in between these two, which is thus a reasonable choice.

I vehemently disagree. Parallel flow already is taking care of by parallel computations, while perpendicular flow, for the currently available range of values for thermal conductivity all values, has an error of at least 100% when using the logarithmic average.