Factorio Forums

What did you do?
- Placed heat pipes in different orders.
What happened?
- In some cases non-conducting pipes after 60 tile (heat drop-off is strictly linear over distance)
- Significant difference in conduction rates based on direction (placing order).
What did you expect to happen instead?
- To get placing-order independent conduction rates from non-directional "pipe".

To reproduce:
- Place down a reactor and fuel it.
- Connect and draw a heat pipe over long distance. Note: Direction of placing is outward from the reactor. (No need to attach to anything) (Call it pipe A)
- Now create a similar line only the other way around. Start placing far away from the reactor and end it by connect it. (Call it pipe B)
- After proper warmup (10 min) running reactor measure the last pipe of A and B.
- Notice that line ending of B is at 15 C while A is around 1000 C

Demonstration: (Image below)
Pipe A is the upper which is 200+ tile long and turns back and return in the middle.
Pipe A was build from starting at the top corner of the reactor then, built rights-to-left along the top then turned back to middle and left-to-right.
Pipe B is the lower which is only 62 tile long.
Pipe B is is started away from the reactor and placed left-to-right and connecting to the reactor as last.

Blue belt marks ~1000C
Red belt marks 500C
Yellow marks 15C

Conclusion: Pipe A is good but Pipe B looses 50% of the source heat over 30 tile (1.6667%/tile) (and 50% means -> Capped at 500C -> this is the maximum distance for turbine placement) I would welcome similar mechanics in the game, but it needs to be consistent and well documented.

Is this still the case? Do i need to place my heatpipes from near the reactor to away from the reactor?

slaphappypap wrote:Is this still the case? Do i need to place my heatpipes from near the reactor to away from the reactor?

As of 0.15.3 yes it is. I do hope its just a bug, as having the freedom to lay out your reactor is awesome, and not just use some cookie cutter blueprint.

I've been running some tests also.
It seems to me pipe B is not loosing heat, it's just preventing from going much further.
When you start with all pipes and reactors at 15C and place the fuel in the reactors, reactor B is warming much faster because reactor A needs to spend much more heat to get the complete pipe up to 1000C.

To make it easy to build big structures situation A is easier, but the challenge in situation B is probably more interesting and I think (hope) B is the intented way it should work.

Related: viewtopic.php?f=7&t=45548

I can confirm that strange behaviour even in 0.15.4

The heatpipes show above described weird behaviour if placed by robots (in random order) or when drawn towards the reactor instead of away from it.

I had to re-do the entire heatpipe network to ensure that it performs correctly.


No wonder I couldn't figure out the weird temperature values shown on the heatpipes at first. I knew there was something wrong, but I couldn't wrap my head around it.

This also appears to apply to reactor plants themselves. I had placed reactors out of sequence on my map and had one in the center sitting 20C below the reactor/heat pipes to either side of it.

Is this issue possibly related to this bug? If so, then it has likely been fixed in the upcoming 0.15.6.

Tekky wrote:Is this issue possibly related to this bug? If so, then it has likely been fixed in the upcoming 0.15.6.

It might be related to that bug, though I was creating it in single player, and in that thread it was stated that the fixed issue was causing heat pipes to transfer twice as fast, not at half the rate, and not in such a way that an item would remain at a lower temperature than the hotter items on either side of it.

From my testing this problem is also present in 0.15.6. Heat seems to favour the direction in which you built the pipes.

Building the heat pipe about 60 tiles long from reactor to heat exchanger works, building the pipe the other way does not work.

saturn7 wrote:From my testing this problem is also present in 0.15.6. Heat seems to favour the direction in which you built the pipes.

Building the heat pipe about 60 tiles long from reactor to heat exchanger works, building the pipe the other way does not work.

There is also an issue where heat items (pipes/exchangers/reactors) can have a near 20C temperature difference between them even when there is no heat being transferred between any of the items. I've also seen hotter temperatures at a north most 'hot' heat pipe, where that one spot is 20C hotter than anything else in the system (even the reactors, operating or not).

This is currently how heat pipes work. The order you build the pipes will change how they behave.

It's not really desired to work that way but it's not a bug. We may change it in the future.

Rseding91 wrote:This is currently how heat pipes work. The order you build the pipes will change how they behave.

It's not really desired to work that way but it's not a bug. We may change it in the future.

Would it then be possible to implement a hint... so that not so experienced players know they have to place it from the reactors towards the heat exchangers and not the other way around?

Something like small arrows every now and then that are shown in the ALT overlay or so.

Because a lot of players don't get that they are directional and there's no hint ingame about it.

Rseding91 wrote:This is currently how heat pipes work. The order you build the pipes will change how they behave.

It's not really desired to work that way but it's not a bug. We may change it in the future.

"A bug is an error, flaw, failure or fault in a program that causes it to produce an incorrect or unexpected result, or to behave in unintended ways."
Like it or not, this is a bug, please reclassify it as one. Flat 1.66667%/tile heat transfer loss is neither 'infinite' nor 'documented'.

I love you guys and your work but this is unacceptable.
Just go ahead and see some stream or video where some player try to figure out the nuclear heat without the knowledge of this bug.
Or the 3500+ view just on this post does not suggest something?

I agree that it would be more appropriate to move this thread to "known issues" instead of "not a bug".

Rseding91 wrote:This is currently how heat pipes work. The order you build the pipes will change how they behave.

It's not really desired to work that way but it's not a bug. We may change it in the future.

I'm sorry guys but this is most definitely a bug - in more ways than one. Something is absolutely broken with the mechanic as it is currently implemented. You guys are the best / most active developers I have seen across any software project ever, but it baffles me that you can look at what heat pipes are doing and say there is nothing wrong with the implementation. You might as well be saying that 2+2=5 is not a bug.

malventano wrote:

Rseding91 wrote:This is currently how heat pipes work. The order you build the pipes will change how they behave.

It's not really desired to work that way but it's not a bug. We may change it in the future.

I'm sorry guys but this is most definitely a bug - in more ways than one. Something is absolutely broken with the mechanic as it is currently implemented. You guys are the best / most active developers I have seen across any software project ever, but it baffles me that you can look at what heat pipes are doing and say there is nothing wrong with the implementation. You might as well be saying that 2+2=5 is not a bug.

There is something wrong with the design of the system, we are aware of this, the mechanic of the heat transfer isn't clear, from a gameplay perspective it isn't working well

However the actual implementation is working as intended, it was written to act as it is acting, and thus there is no bug.

We have had some discussion about changing the way they work, but as it stands, it is working as it was designed

So we can't use blueprints and construction robots to build heat pipes? I haven't tested it, but based on the comments there it seems that is the case?

imajor wrote:So we can't use blueprints and construction robots to build heat pipes? I haven't tested it, but based on the comments there it seems that is the case?

Pretty much yes.

The robots would place them in random order so they wouldn't work the way the player wants them to.

This bug is still not fixed in 0.15.9 Why is this "Not a bug"?! Placement order matters now? What about blueprints? Robot construction? We all have to "live with this?"