Heat mechanic and radiators

[ebigunso]

So I've been searching around about the radiators and heat mechanics in general, but couldn't find any source with info on how much radiators I need to keep a craft safe and cool.

I've launched things without radiators and that unsurprisingly has heated up quite a lot so I assume you do need at least some per craft, but I don't know how much is actually needed. If anybody has found out about this, please give me some advice

Oh btw that craft I launched without radiators were a space station part, so none of those nuclear engines were on board.

Edited September 9, 2015 by ebigunso

[1greywind]

There is option "show termal info on right click" in debug menu (Alt+F12). Turning it on will allow you to see actual temperature and heat flow rate on selected part. And after some experiments you can precisely determine how many radiators you need.

[Highguard]

Everything I've read says you don't need any, they're a hangover from 1.0.2 or something.

They're useless or even positively dangerous during ascent/descent in an atmosphere, since it's the outside atmosphere itself that is heating the ship.

In vacuum even around Moho things shouldn't get hot enough to explode.

[Mikki]

Everything I've read says you don't need any, they're a hangover from 1.0.2 or something.

They're useless or even positively dangerous during ascent/descent in an atmosphere, since it's the outside atmosphere itself that is heating the ship.

In vacuum even around Moho things shouldn't get hot enough to explode.

Some engines in vacuum explode without active heat management, example the "Nerva" LV-N`s. Depends on how long you have to burn, stock radiators, solararrays and large tanks avoid overheating efficiently, or can decrease the heat entirerly. As soon as the overheat gauges appear aside the fuelstats you know you get in trouble perhaps.

[Warzouz]

Yes, Heat stuff is only needed if you do long burns with LVN (Nerva).

Remember that a 50% overheating is not dangerous. Even 90%. You can live with it nicely.

Usually, when heating is not under control, it rises so fast that you can't do anything about it.

[Randazzo]

Heat in KSP doesn't really mean anything until you explode, unlike IRL where you will be boiled/broiled/baked/roasted alive long before your ship detonates from ambient heat. If you're playing a stock game, then the vast majority of your vessels won't need any heat controlling devices most of the time. I'm not really sure why they bothered to add the radiators at the same time they removed the only reason they were needed in the stock game. Perhaps future releases will make them useful again.

Now if you use mods, particularly ones with more nuclear engine choices, or reactors, then you start seeing a real need for them.

Edited September 8, 2015 by Randazzo

[Hagen von Tronje]

There are only so many sources of excess heat:

- The LV-N engine

- Being close to Kerbol (the sun)

- The kraken!

- Assorted mod parts

Unless I'm having a brainfart and forgetting something, that means that if you're playing stock and not using nuclear engines, if your craft is getting hot enough to show bars* then you're either in close orbit around Kerbol or orbiting one of the inner planets, or you're experiencing bugged overheating.

A lot of old tutorials mention drills generating heat but this is no longer the case, as least from my experience. Doesn't appear that ISRU or any other machinery does, either.

This also means that in a stock game, the only thing radiators are useful for is extra low TWR nuke stages with truly epic burns, since it still takes quite a long time for nukes to heat up enough for radiators to even do anything at all, much less be necessary.

*As mentioned above, showing bars means doesn't mean danger, bars show at 40% critical temp. Worth noting that craft being heated by the sun will reach equilibrium, and there is no damage caused by long-term heat exposure, so your Moho satellite could be at 60% critical temp permanently and it's just as good as if it were room temperature.

[Laie]

Some engines in vacuum explode without active heat management, example the "Nerva" LV-N`s.

No more. Since 1.0.4, it's pretty hard to build a ship that will suffer damage from Nervas. This may change when you get closer to the Sun. Like, a mission to Moho.

What bugs me about the current heat system is that it's seemingly impossible to keep the crew quarters cool during long burns. The extendable panels help a bundle, but still a lot of heat seeps and crawls and spreads through the entire vessel until the whole thing reaches equilibrum at some high temperature. No matter how many parts I place between engine and quarters, there's barely a gradient.

[ebigunso]

I'm not sure if it's a bug since I have so many mods installed, but in my case OKS modules in Kerbin orbit went up to almost 80% of the heat gauge in the overlay. Mods I can think of that might affect this would be RealFuels?

I later brought up a module with a bunch of radiators and that itself didn't experience the heating issue but still seeing if it helps cool the main station.

Edited September 9, 2015 by ebigunso

[ebigunso]

Looking at the temperature indication, it looks as the skin temperature is becoming extremely high. Part temperatures remained nominal at around 273Kelvin.

EDIT: Bad news. One of the modules spontaneously exploded due to the heat. I'm suspecting this to be a bug now...

https://kie.nu/2IwY

here's my output log if anybody wants to check out what's going on. The explosion event is marked on line 216655.

Edited September 9, 2015 by ebigunso

[Streetwind]

Yes, it's a known bug. A fix was just announced yesterday as coming with the next patch.

[ebigunso]

Yes, it's a known bug. A fix was just announced yesterday as coming with the next patch.

Awesome. Looking forward to that

Thats a KSP patch you're talking about right?

[Mars Mullo]

I'm having trouble understanding these too.

I launched several satelites and the rockets were the same except that some had three of the smallest radiators on them.

The returning rocket stage into atmosphere were all burning up and destroying on contact with water.

Of note the ones where I had three radiator pannels survived the atmosphere... but he Swivel motor was blowing up.

The swivel was reaching very high temperatures.. 2000 degrees plus.

The radiator panels were at the opposite end of the rocket. About two long 1.25m tanks away)

I think if i had them closer to the motor end it might have survived.

I had three fins and they survived.. but the swivel motor didn't acting as a heat shield.

I was entering art speeds of 2300m/s.

I always use the ofset tool to pus the flush pannels closer to the tank to look better.