Active refrigeration

[Snark]

Lengthy rant below, but what I'd like to see boils down to the following:

• I want active refrigeration that can cool things down
  
• I want it to be "realistic" in the sense that it doesn't magically destroy heat, just moves it from point A to point B, at a cost of electricity and additional generated heat
  
• It would be great if it worked naturally with radiators
  
• It should be simple to play/use, without excessively complicating the game
  

(What triggered this rant was the off-hand mention of "the radiators can now be hotter than the parts they're cooling" in the 1.0.5 announcement, which sounds like they're may just make them be magical free refrigerators, which is fundamentally impossible in a way that bugs me a lot. This seems to me to be an opportunity for an interesting gameplay mechanic).

Okay, the details:

Currently, the active radiators (the sun-tracking ones that fold up) actively suck heat out of components anywhere on the ship... but only if the part is hotter than the radiator itself. This is helpful for keeping nuclear engines from exploding, but not helpful for keeping low-heat-tolerance parts (such as science instruments) from exploding in a high-heat environment (such as flying close to the sun).

I'd really like to see active refrigeration as a feature, so that things can be actively cooled off. More specifically, I'd like to see it implemented in a way that is realistic enough to present design challenges and preserve the immersive nature of the game, without being tedious or confusing (gameplay has to come first).

Specifically, I'd like to see a new set of parts added: refrigerators, in various sizes. How they would work:

• A refrigeration unit is fairly heavy, e.g. 1 ton for a 2.5m unit. Heavy enough that you don't put it on your ship unless you need it, but not so heavy that it really warps the ship design.
  
• Thermal properties:
  
  • High specific heat (takes a lot of heat to raise its temperature).
    
  • High max temperature (e.g. 2600 would be good).
    
  • Low thermal conductivity (parts next to a hot refrigerator don't get hot easily).
    
  • High emissivity (it radiates well)
    
  • High core-to-skin conductivity (gets its heat up to the skin quickly so it can radiate)
    

  [*]The refrigeration can be toggled on and off (via right-click menu button, or action group).

  [*]When refrigeration is turned on:

  • Does nothing unless there are "hot" parts on the ship (defined as "above 50% of the part's max temperature").
    
  • For any "hot" parts, it pulls heat from the "hottest" parts to itself (where "hottest" is defined in terms of "percentage of part's max temperature").
    
  • It ignores radiators (never tries to pull heat from them).
    

  [*]Refrigeration isn't free. It obeys the 2nd Law of Thermodynamics.

  • It requires electricity to run. The electricity required per unit of heat pumped goes up with the temperature differential (i.e. pumping one unit of heat out of something that's 200 degrees cooler than the refrigerator takes more electricity than pumping the same amount of heat out of something that's only 100 degrees cooler than the refrigerator).
    
  • It generates heat (that is, running the refrigerator causes the total heat in the ship to go up). The generated heat is dumped into the refrigerator. The amount of heat generated is proportional to the electricity used.
    
  • This is the show-stopper feature for me-- it "keeps it real" and keeps the gameplay believable, while adding an element of strategy for ship design.
    

Q & A:

• Q: The refrigerator makes your ship hotter? That seems dumb. Shouldn't it work like a real refrigerator?
  
• A: Actually, that is how real refrigerators work. Your refrigerator makes your house warmer. If you leave the door open, it just heats your house faster.
  

• Q: But if it makes your ship hotter, why would anyone want to use it?
  
• A: It makes the refrigerator hotter. The refrigerator can tolerate a very high temperature and doesn't transmit much heat to the parts around it. What it does is protect the vulnerable parts on your ship (the ones with low temperature tolerance) from overheating.
  

• Q: But won't the refrigerator eventually explode?
  
• A: Well, depends on how heavily loaded it is. When the refrigerator gets really hot, it will start radiating heat. If it's not working too hard, that might be enough. If it's not enough, you can mount passive radiators on it to help it dissipate heat. You can also mount the active folding radiators somewhere on the ship, and they'll actively suck heat out of the refrigerator because it's hotter than them. The refrigerator design dovetails nicely with the active radiators, in this way. No code change to the radiator behavior is needed.
  

• Q: But I remember reading in the 1.0.5 announcement that they're going to add active cooling as a stock feature. Why would we need this?
  
• A: Well, I would love it if the solution that Squad implements looks something like this. However, all they said was: "the radiators can now be hotter than the parts they're cooling, allowing for active refrigeration". There are no details there... but I'm concerned that they're just going to make the radiators magical so that they cool down everything for free. That's what bugs me. Refrigeration shouldn't be free, it should take something heavy and power-consuming to work. Magical free-refrigeration radiators will make heat management a complete non-issue, just slap a bunch of radiators on and you're good. Given that there actually aren't any details out yet, I suppose I should save my rant. Just want to add my vote to any Squad devs listening, "please make it interesting".
  

• Q: Well, there's a mod for that, Heat Management. It has active refrigeration units.
  
• A: It's a neat mod, and looks really well done. (In particular, its active sun-tracking radiators actually work, unlike Squad's which currently have a bug that ignores sun tracking). However, the refrigeration units in it are implemented as "ablators": they cool by using a consumable resource (NH3 coolant), and once that's used up, you can use electricity to fill up the coolant again. In other words: it just makes the heat go away. That's an interesting gameplay mechanic, but it's not really the one I'm looking for-- real refrigerators don't make heat go away, they just move it from point A to point B, and there's still the problem of what to do with all that heat at point B when it piles up. "Radiators" is the answer: I want to see refrigeration that works together with radiators.
  

[CaptainTurbomuffin]

Yes, I suggested something similar once. It was in a suggestion for hypersonic planes. What I suggested was water-cooling. A pump could be connected to certain parts. Tanks of water could be used to cool the connected parts. Once you're out of water (alll your cold water is turned into hot water). It could be a lot stronger than radiators, could be used during flight ( you won't have to extend radiator-sails) , but it's short-term. Depending on your ammout of water you have, and the rate you heat it up (the ammout of pumps you use it with. The ammout of water determines the heat storing capacity, the number of pumps the cooling rate) it would run out after 1-2 minutes. After that, the hot water could be cooled back again with on-board radiators. But, of course, no super high-speed flight, no need for anything like that.

But anyway, don't radiators transfer the heat to particles in space?

[Snark]

That's fine, and great, and no problem with that. Radiators work great in real life, and are in fact what spaceships (such as the ISS) use to keep from stewing in their own juices.

Where I take issue is if any part (radiator or otherwise) can move heat uphill for free.Heat naturally flows from hot things to cold things, it's how the universe works. To move heat in the wrong direction (i.e. from a cold thing to a hot thing) therefore takes an unavoidable amount of work, which is why real-world refrigerators A) generate waste heat, and take a lot of electricity to run.

The way the radiators are in the game now (1.0.4), they're not violating any laws: they're just moving heat from a hot thing (a part on the ship that's overheating) to something cooler (the radiator itself), and then again from the radiator to the background temperature of space, which is near absolute zero.

But to make a change so that a radiator can suck heat out of a part that's cooler than the radiator-- that's what sticks in my craw.

[kerbiloid]

And icy accumulators...

http://www.forbes.com/sites/peterdetwiler/2015/10/27/when-it-comes-to-energy-storage-dont-leave-ice-out-in-the-cold/