Automation limitation issue

[Ihasfeet]

I’m running into a limitation with automation in Oxygen Not Included and I think a new automation feature could solve it.

 

My setup:

 

I have two stacked rooms.

• The upper room is a steam room with an aquatuner, hydrogen generator, and metal refinery running inside it. Steam turbines are placed directly above this room to delete heat.

• The lower room is a separate chamber with coal generators and gas generators. I kept them separate so their gases don’t pollute the steam room.

 

I built a closed oil loop that runs between both rooms so heat from the lower room can be transferred upward into the steam room, where the turbines can delete it.

 

 

What I need:

 

The oil should only flow when the lower room is hotter than the steam room.

 

If the steam room is already hotter than the lower room, the loop should automatically stop, otherwise it just transfers heat in the wrong direction.

 

 

In plain logic terms:

 

If Steam Room Temp > Lower Room Temp → Stop oil flow

 

If Steam Room Temp < Lower Room Temp → Allow oil flow

 

 

The problem:

Right now, ONI automation doesn’t allow direct comparison between two sensor values. Thermo Sensors only compare against a fixed number, not against each other. This means I can’t make a true “room A vs room B” control system — I can only use arbitrary thresholds, which doesn’t really solve the problem.

 

Feature Request:

Please consider adding a Comparator Gate (greater than / less than) to the automation system. This gate could take two sensor inputs and activate when one is higher/lower than the other. It would make setups like heat-transfer loops much more intuitive and open up lots of creative automation without needing

mods or awkward workarounds.

[Charletrom]

Usually when I encounter an issue like this it’s because my design is overcomplicated. Have you considered using mechanical doors between the two rooms to inject heat into the steam chamber?

[axxel]

The threshold is how hot the steam room can achieve and when the overheat damage stops the generator buildings. If you want to compare two room temperatures keep in mind a failing steam turbine chamber will allow oil flow but does not do nothing useful to the generator room. You can "compare" roughly two room temperatures if you use multiple thermo sensors with X°C increments. 

[SGT_Imalas]

the lower room setup you describe is deleting more heat than it is generating

see this post for the math:

Edited August 28, 2025 by SGT_Imalas

[Gurgel]

On 8/28/2025 at 6:05 PM, Charletrom said:

Usually when I encounter an issue like this it’s because my design is overcomplicated. 

I second that. There is probably a way to simplify this and do without temperature comparison. 

[KittenIsAGeek]

On 8/28/2025 at 9:06 AM, Ihasfeet said:

Right now, ONI automation doesn’t allow direct comparison between two sensor values. Thermo Sensors only compare against a fixed number, not against each other.

I've had this issue before.  I automated the water return from my steam turbines to maximize the power generation when a volcano was not erupting.  My method involved two thermal sensors and an S/R logic gate.  Essentially I set the water to stop flowing of the temperature was below a point, and start the water flowing when the temperature was above a certain point.  The output from the S/R logic gate went into an OR with another S/R logic gate that connected the "start water flowing" thermal sensor and the output from the reservoir to make sure that the reservoir was flushed at the start of the volcanic eruption.

Anyway, the S/R logic gate is how I can compare > or < values between two sensors.

[Cmagik]

On 9/19/2025 at 7:29 AM, Gurgel said:

I second that. There is probably a way to simplify this and do without temperature comparison. 

Nonetheless, 

it is kind of odd that we have multiplex signals which is barely touched by anyone but not a signal comparison. 

I'm not saying there's no way around that, but I don't see the arm in adding a new automation which would probably see some good use.

[Alexander Block]

@CmagikTo compare signals, you need to introduce analog automation into the game. This is a new mechanic, not a new device.

[Cmagik]

8 hours ago, Alexander Block said:

@CmagikTo compare signals, you need to introduce analog automation into the game. This is a new mechanic, not a new device.

That's actually a really good point. 

Since we're on the topic, anyone else feels like an automation which sends an green signal when the device is being used would be nice. 

[gigamoi]

22 hours ago, Cmagik said:

Since we're on the topic, anyone else feels like an automation which sends an green signal when the device is being used would be nice.

I usually use a duplicant detector or pressure plate for that. Wattage sensors work great for power hungry devices such as the wind tunnel. Sensing fluid backup/presence can also do that when applicable.

[Alexander Block]

I really miss the fact that you can't configure the logic elements during construction. Because of this, you have to disconnect the power supply, otherwise the circuit won't work correctly.

[SGT_Imalas]

8 hours ago, Alexander Block said:

I really miss the fact that you can't configure the logic elements during construction. Because of this, you have to disconnect the power supply, otherwise the circuit won't work correctly.

that exists as a mod atleast

[Alexander Block]

@SGT_Imalas Tell me the mod name, please.

[SGT_Imalas]

Blueprints Expanded - allows preconfiguring buildings by reusing the blueprint data transfer components

[Gurgel]

On 9/25/2025 at 9:00 AM, Alexander Block said:

@CmagikTo compare signals, you need to introduce analog automation into the game. This is a new mechanic, not a new device.

Yes. Instead of clocked 0 and 1, you suddenly need to shift at least a short float. And since transfer is clocked, you probably will run into a oscillation and instability issues. Also, because this increases the memory footprint of the simulation core, it will slow things down.