Question about the surge crucible in Erekir

I'm a returning player, checking out this erekir stuff, and I just unlocked this thing. But it needs 40 heat units, and the only way currently to make heat is an oxidation chamber, which only makes 5.

So do I need to somehow have 8 oxidation chambers active at once to make surge? Cus that seems kinda ridiculous. Am I missing something?