# how many DTU/s transfert a pipe?

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Hi there!

I'm a little bit lost. I'm trying to calculate a little bit more precisely how much heat I need to exchange to cool down specific part of my base.

I understand the principle that each building emit certain DTUs, and some are canceling that. but... if I create a cooling machine and cooling down a liquid (and/or a gas), how do I know how much pipe I need to cool down an item?

Example:

• I want to build a Petroleum generator, which produce +20 kDTU/s
• I have in a remote location a cooling station balanced with 3 aqua-tuner and 2 steam turbine, which DTU is balanced, and reduce the temperature of polluted water of -14˚x3 = -42˚ (i guess per s? o per pipe content? I'm confused here)

how many radiant liquid pipe I need to balance that 20 kDTU/s?

all of this is to properly calculate how many things I can cool down with just one cooling station. or similiar application, how many steam turbine I can cool down with just one aquatuner.

many thanks!

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There's not way other the pratically test it, like in sandbox mode.

Heat transfer equations are well-known, but not pratical to work with. They depend on too many factors and and behaviours. For example, heat transfer in gasses is dominated by random movement of tiles of gas rather than actual heat transfer. So basicly at any tick in the game when the heat transfer equation is applied, you have no way of knowing or predicting which actual tile of gas the trasfer occurs with, so you're missing the basic variables of said equation, temperature and mass.

Also, you don't really need that information. Ok you might need to know what is the minimum lenght of radiant pipeof a given material is needed to achieve a result, but usually you just overdo it by many times... not to mention that there's a tendency to equilibrium.

Take your case... say you have one one segment of pipe that is radiant, all the rest perfectly insulated. If that single segment doesn't transfer enough heat, the generator, next tick, becomes hotter. And so on, but the hotter it becomes, the more heat it transfers. There is a temperature at with an equilibrium is reached.

Now, that temperature might be unsuitable for reasons... it could be above the overheat temp of the generator. Or the combination of the initial temperature of the coolant and the heat it receives while passing thru that single radiant pipe segment could make it boil, breaking the pipe.

In order to compute the amount of heat transferred in those condition you'd have to know all the relevant variables... in certain conditions it could be done I guess.   But usually you're working in a range that is so much away from that point that you don't care about exact numbers. You'd use a different coolant, allowing for lower initial temperatures. Usually there's more than one radiant segment, making calculations very tricky.

Again best way by far is to go in sandbox mode and test the build you have in mind.

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Two or three segments is more than enough.  You will also want a shutoff to stop the flow of cold water when the temperature is cool enough.

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thanks guys.

personally I don't like the sandbox. it's too much artificial, good for testing the "perfect machine" in a close environment, but then anything done there found no practical application in the actual game. I like the challenge of working with what you get.

I guess the shutoff could be a good solution. I'll make my cooling station and then branch it as a tree, with shutoff along the way. could work.

next stop. taming a volcano! :P

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5 hours ago, Nerokiwi said:

I want to build a Petroleum generator, which produce +20 kDTU/s

For generators made of thermium You can make them self cooling in the easiest way possible:

This example (made in sandbox) is for constant power output and it stabilizes itself around 126*C with max pressure around 11kg/tile (CO2 and Steam). It is working for 40cycles straight and reach 120*C within first 2-3 cycles. Generators are made of thermium, walls from gold. Dry walls are just ing rock.

Below is what I am using for power distribution in survival game. It is designed for non constant use and I decided to add some cooling made of any waste gas. Cooling is required for transformers since they are heating constantly they might overheat in vacuum. I wish there was a passive pressure valve.Generators and batteries are made of thermium, walls from copper. Dry walls are just ing rock.

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As psusi said, the number of radiant pipes you need if you are trying to minimize them is not very many. You might not need more than one aquatuner too.

Let me share an example. I guess it's relevant to your next project too.

• Left section: heat deletion via turbine.
• Right section: thermal battery kept at target temperature.
• Top section: turbine cooling.
• Aquatuner is turned on when coolant rises above target temperature for more than 25s (with filter gate).

You can use the same sort of loop and just extend the radiator piping to wherever you need to regulate the temperature. In this case it's just going to the atmosphere. If you do need multiple aquatuners worth of cooling, it can be simply extended.

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1 hour ago, Nerokiwi said:

thanks guys.

personally I don't like the sandbox. it's too much artificial, good for testing the "perfect machine" in a close environment, but then anything done there found no practical application in the actual game. I like the challenge of working with what you get.

I guess the shutoff could be a good solution. I'll make my cooling station and then branch it as a tree, with shutoff along the way. could work.

next stop. taming a volcano! :P

I don't agree much. These days, I test things in survival directly, but I've build my first boiler in sandbox. It's just a different savefile of your actual colony. It saves you tons of time in building and mostly changing it. For example, I had to move some stuff around and change the material of a few pipes. I usually don't copy verbatim designs I find elsewhere. I change them trying to understand how they work... usually I try something simpler just to understand why something has been designed is a certain way.

The boiler i've designed in sandbox mode was later built in survival by dups. By no means a "perfect machine" but absolutely pratical in a real game.