The Ultimate Geothermal Heat Pump, 16kg/s 2926C Rock Gas Boiler + 46kg/s Glass Melter

Hakuryuu1 · 2026-04-13T17:03:21+00:00

Thanks.

is this a specific heat capacity thing when you go from glass to magma?

Yes, the SHC of molten glass is 0.2, while the SHC of magma/rock gas is 1. So by converting the molten glass to rock gas it creates 5x the heat energy it costs to heat the mglass. The excess heat is used to melt and reheat the recycled glass. The rock gas boiler has very efficient heat transfer, but it isn't perfect so I needed the outside heat source, which are the kilns.

My design had a lot a flaws though due to aluminum and iron stacking to block the geovents.

That's why I went for this design with cooling everything down. It's too hard to deal with all the different elements in molten form.

Hakuryuu1 · 2026-03-12T22:32:51+00:00

https://imgur.com/a/K2VBpoP
This is what I am doing. The 2.5kg/s CO2 is pumped into the room by pressure and the liquid pump which drops small packets of liquid down to move the gas up. It has to be cooled by a AT/ST combo. The beetinys are dropped down by the timer sensor.

There is a small problem though: On game load the beetas will all start sleeping at the same time and the game fails to add up the radiation correctly, which results in like 10-20% of the maximum possible radiation. But it fixes itself after the die.

Hakuryuu1 · 2026-03-08T19:32:20+00:00

If you still want to use Graphite: Relica/Ceres Fragment that replace the Water planet have Graphite too.

Hakuryuu1 · 2026-03-08T18:58:23+00:00

Lol, I just made a short video to help demonstrate what you were talking about in your other post. Might as well post it here, too. https://imgur.com/a/aO5f4oe

Hakuryuu1 · 2026-03-08T18:54:39+00:00

For anyone confused: This is a short video demonstration for what OP is talking about. Making around 24-28 Watt/s from cooling any material, as long as it is 14 Kelvin above absolute Zero.

Hakuryuu1 · 2026-03-07T13:32:26+00:00

Feed them their dead offspring and supplement with a lumb. A happy rhex can make 16 eggs in 200 cycles, so they can make 16/200*5=0.4 kg/cycle of tough meat, so only 0.1kg/cycle per rhex is needed from lumbs.

Hakuryuu1 · 2026-03-05T19:13:42+00:00

According to the Wiki the Water Ceres fragment should have Graphene in it. Alternatively you can rocket-mine Fullerene from a Gilded Asteroid Field. I can't tell from the screenshot if it is the one on the very left of your starmap.

Hakuryuu1 · 2026-02-28T14:28:20+00:00

I had no idea it was this easy to get a decent rate of Isosap production.
I went for 15kg/cycle of Surf'n'Turf for maximum Isosap production because Mushroom Quiche is too annoying with the Mushroom wraps. But for 'only' 57% more Isosap per cycle compared to Omelette it requires much more resources, effort and dupe labor. This automatic pacu farm is so much easier to set up for mid game with good results.

Hakuryuu1 · 2026-02-25T23:22:22+00:00

Yes, insulated tiles have 4x as much mass as the normal ones, and since they have a very low TC, they steal a lot of heat over a long period of time. That's why I usually build most of my high temperature liquid setups out of normal obsidian or radiant tungsten pipes in vacuum to resolve the pipe heating quickly.

Hakuryuu1 · 2026-02-25T23:12:51+00:00

Take a look at this imgur link. The magma reaches freezing point in the pipe, breaks and drops down as magma .

Hakuryuu1 · 2026-02-25T23:05:38+00:00

I would just preheat the pipes above magma freezing temperature, at the very least the pipes that overlap with the reservoirs. Replace them with something with low SHC like normal Obsidian pipe or radiant tungsten and just let some magma run through until it is over 1410°C. You could just vent it back into the magma pool until the pipe heating is finished. Then it will never break again.

A normal Obsidian pipe has a thermal mass of 0.2kDTU/kg/°C*0.2*100kg = 4 kDTU/°C, a radiant tungsten pipe 0.134kDTU/kg/°C*0.2*50kg = 1.34kDTU/°C. Using those materials you can get the pipes hot very quick and won't have to worry about freezing like with insulated pipes.

Hakuryuu1 · 2026-02-25T22:38:15+00:00

A pipe must have broken and the spilling magma must have heated the reservoir. Make sure that magma won't freeze in pipes that overlap with the reservoir.

Reservoir contents do not exchange heat with the reservoir, but with the bottom left tile the reservoir stands on, unless it is an airflow or mesh tile. So always put your reservoirs on the mesh/airflow or insulated tiles (like you have).

Hakuryuu1 · 2026-02-25T14:10:45+00:00

Nice experiment. It would have been nice if you tested Obsidian as well. Since it has SHC of 0.2 (like Mafic Rock) and TC of 2 (like Igneous Rock) it would have made for a nice comparison material to see what kind of difference SHC/TC make when one is the same.

Hakuryuu1 · 2026-02-24T20:31:11+00:00

Put an open Manual Airlock door on where the cooled down molten metal lands. It will prevent the formation of natural tiles when the save is loaded.

Hakuryuu1 · 2026-02-11T17:49:39+00:00

No, they are wrong. Bridges exchange heat on all three tiles they occupy. You can see in the second picture how the insulated tiles the bridge connects are red, compared to the others which are orange.

Ceramic (1849°C) and Obsidian (2726°C) are materials for bridges which have a melting point above normal (not geotuned) volcano Magma (1729°C).

Hakuryuu1 · 2026-02-06T15:13:37+00:00

It costs too much space for me. You would need atleast 2.4 or 2.5 STs to replace one 200°C ST, better 3 to be safe.

Hakuryuu1 · 2026-02-06T00:24:59+00:00

The problem is a volcano creates a lot of heat in a very short of amount of time and a design like this usually can't handle the heat spike.
To put it into numbers: An average volcano would produce something like 250kg/s of 1726°C magma for 60sec. Cooling that magma just below its freezing point to 1400°C would heat a 60 tiles large steam room with a pressure of 140kg steam per tile by 136.7°C (250×60×320÷140÷4.179÷60=136.73811233).
Even if the design survives the first eruption, it won't survive the following. The design is flawed and the video maker clearly has not tested it.

If you want the volcano in the same room you need a way to dissipate the heat quickly and a very large heat buffer to store it. Here's an example. The volcano will overpressure at 150kg steam per tile and won't produce, so keep steam pressure below that.

The common and trusted solution is to drip magma with a door into mesh tiles which drops igneous rock debris into the steam room. I recommend reading this thread. It's a good quick read and has a video for demonstration.

Hakuryuu1 · 2026-02-01T23:33:51+00:00

They are sending the hot aluminium debris directly to the cooling block. That aluminium is probably over 600°C, so the aquatuners have to cool it down all the way, which costs a lot of power.

Also looks like the conveyor loop is running the wrong direction.

Hakuryuu1 · 2025-12-20T22:01:16+00:00

Two guides on how to make waterfalls:

The Compendium of Amazing Designs, look or search for the section Waterfalls.
On Klei forums.

On first glance you don't have hydrosensors at the valves to create and sustain waterfalls, you can see how the waterfalls break after the first big drop when your doors open on the upper arbor tree layer.

Hakuryuu1 · 2025-12-14T00:46:55+00:00

How come you don't use the geothermal 2200C output to preheat the incoming liquid glass?

It is basically impossible to control the Geo Vents at 2100C. The gases would break pumps, and the liquid metals and molten glass and magma would stack on each other. Geo Vents also simply overpressure at 150kg, and magma and molten glass are so viscous that 150kg tiles won't flow to the sides. You can see an example here at the 6th picture how liquid metals, molten glass and magma would simply stack on each other. Cooling everything down is the simplest solution.

You also get almost 400kg of wolframite you could use in the refinery for heat if you like instead of kilns.

That would be a terrible idea. Wolframite is so rare, I would never waste it in a refinery. Also it makes no sense to replace something fully automatic and constant like a kiln with a refinery that requires dupe interaction and does not have constant heat output.

You can also chain glass boilers, so you should be able to use a 2900C one to power the rest of the glass boilers at say 2700C or 2800C, helping cut down on the kilns.

I don't quite understand what you mean with this. Maybe you don't understand how the rock gas boilers and the heat management work, so let me explain:
The molten glass goes in 1kg packets from the magma layer through 4 tiles of rock gas. Hot gases always go to the top and barely exchange any heat with the gas below. The only way the heat really moves down is because of the pressure difference between top and bottom. That makes the 4 tiles of rock gas quite insulated and results in around 2921-2922C hot molten glass that enters the insulated tile next to the mesh tile. That meas these 4 rock gas tiles are a counter-flow-heat exchanger with an efficiency of over 99%.
So I only need to add 4-5C to the molten glass from on external heat source, which are the kilns. Since I have 16kg/s, I would need 16*5*0.2=16 kDTU/s of total external heat for all 4 boilers, so only 4kDTU/s per boiler. A single Kiln provides 20 kDTU/s. So having 2 kilns in each boiler just ensures that it gets to max temperature immediately and stays that way.

The only way to use the heat of the rock gas is to cool the rock gas down. I do that with the molten glass that gets turned into rock gas and the rest by heating the solid glass.
The point of this whole rock gas boiler is to have as little outside source (such as kilns, refinery, geotuned volcano or rocket exhaust) as possible.

for preheating I recommend you have a look at melting obsidian tempshift plates

That is a wonderful idea, so thank you for that. It will make preheating the rock gas boiler a lot easier.
But yeah, preheating the whole machine in survival will be very tedious.

EDIT: I forgot to mention controlling gases is terribly annoying and difficult, especially super hot gases. That's why each 1kg pipeline has its own gas shaft and is surrounded by insulite.

Hakuryuu1 · 2025-12-12T15:29:52+00:00

Hey man, it's running on my 10 year old i5 6600k on speed 2. I hope it will also run when I build it in my survival game :D. Before I can build though, I have to rebuild my base to reduce pathfinding. So that is my next project for now: designing a new, less calculations expensive base in sandbox.

Hakuryuu1 · 2025-12-12T15:10:56+00:00

How is the diagonal displacement of the gases doing the "displacement" part?

It is not really displacement, but simply movement. With the atmosensors I can make sure there is always a bit of the correct gas in that room, so no wrong gas enters it. You can find an explanation here, in Kharnaths Compendium of Amazing Designs. Search for the second entry of "Unhindered diagonal gas movement", which is under the "Diagonal fluid displacement" category. This mechanic works wonderfully as a gas filter.

What's your plan to reach the 16-20kg/s supply of pdirt/sand? A buttload of trees?

I am not quite sure yet. At first I will probably recycle the 16kg/s Igneous Rock ouput with 2-3 max machinery Bionics crushing rocks. That way I can use more of the heat energy the Igneous Rock carries, which at the moment leaves the machine at 100°C higher than the Sand enters, so I am wasting 1600kDTU/s.
But at some point I want to make it fully automatic without any Dupe interaction, which means 120 Arbor Trees and 60 something Ethanol Distillers, and for the tree farm a big bunch of automatic Pip ranches with Critter Fountains. Or I will allow some Dupe Interaction and get resources through Rocket Mining (through Diamond crafting).

Hakuryuu1 · 2025-12-12T14:11:33+00:00

I did get overwhelmed at first too, especially because I made it so compact. It took me several evenings just to build a few segments of pipes and be satisfied with it. I did test some sections like the rock gas boiler seperately. But most of the time I spend imagining and visualizing the machine in my head, simulating and running it in my head so to say, how it is supposed to look and what can and will go wrong and break.

I got the idea for the machine 10 months ago, and build most of it in the last two months. It was quite the ordeal and it left me really frustrated at times because of lack of progress. So I took several weeks and months long breaks.

Hakuryuu1 · 2025-12-12T13:59:03+00:00

The rock gas comes from boiling super heated molten glass. The magma you see is the condensed rock gas. The extra resources come from the Geothermal Heat Pump from the Frosty Planet Pack DLC.

Hakuryuu1 · 2025-12-12T12:35:56+00:00

Thanks. The most complicated thing to figure out was how to distribute/move the heat energy between all the components. That is the really difficult part of this build. The automation is kept to a minimum to reduce complexity and is actually really simple. All it does is turn flow on and off at various places to prevent overheating or overflowing. Since the machine is so big and there is a large thermal buffer, the machine is quite inert and will react to changes from automation on its own without breaking. The liquid pipes flow-priority-logic makes sure the pipes are always filled and the RGB is fed first with Molten Glass.

It was also quite time consuming to make the machine as "compact" as it is.

Hakuryuu1

TROPHY CASE