How do gas pumps work? What tiles do they draw from?

[Ash//Fox]

Trying to optimize a SPOM I have, basically just a 3 tile high small room sealed off with a gas pump in the upper corner, I notice while watching it a lot of the packets that come out are pretty small. Would it be possible for me to set up an atmo pressure sensor to make sure it's only pumping out larger packets and if I do that am I going to run into problems getting enough hydrogen out? Would it matter where I put the atmo sensor?

Here's what it looks like:
https://steamcommunity.com/sharedfiles/filedetails/?id=2825915957

[cswiger]

The area of effect is a diamond shape; this mod is helpful:

https://steamcommunity.com/sharedfiles/filedetails/?id=1960996649

Yes, you could add an atmo sensor. Using a Gas Filter is so power inefficient that the location won't matter much.

There are much more power efficient designs using top and bottom gas pumps to take advantage of gas separating into layers without the filter. Even a Gas Element Sensor + Gas Shutoff Value would use much less power.

(A common design that does not take advantage of exploits is the Rodriguez and half-Rodriguez SPOMs. People who use exploits seem to like the Hydra SPOM.)

[Angpaur]

In case of pumping 2 different gases from an electrolyzer the small packets of hydrogen are not a problem and totally natural occurence. Gas pump can output only one gas type per second. 5 times per second it tries to suck 100g of gas from a one of 5 tiles of a cross shape range.

So it can happen that during one second it will pump 200g of Hydrogen and 300g of Oxygen and will output 200g packet of Hydrogen.

Next second it can pump 100g of Hydrogen and 400g of Oxygen and will output 700g packet of Oxygen.

There is no power wasted in such case. You will waste power if there is less than 100g in a tile a pump tries to pump from each 0.2s

here you can learn more about gas pump range: https://forums.kleientertainment.com/forums/topic/91094-the-mystery-about-pump-range/