How many oxygen diffusers do i need?

[Terry Hesticles]

I set up another, but is there a general rule of thumb?

[Angpaur]

A regular dupe consumes 100g/s of oxygen. Diffuser produces 500g/s. So now just do the math including number of duplicants you have.

[Bobucles]

100g/s of oxygen, 1000kcal/cycle of food.
Diffusers will harmlessly wait if the air is high pressure, so there's no penalty for having a few extra. They are cheap to build and maintain, and extra oxygen is very useful. Place them anywhere your dupes want to breathe.

The resource tracker on the right of the screen can be used to keep you updated on critical resources. Set it to constantly display algae (coal is also good). A small colony of 6 dupes will demand 0.4Tons of algae to breathe, every cycle.