The world Monifactory takes place in is generally a world without magic. While there are magical materials that can break the laws of physics, there aren’t any overtly magical things. Almost everything is something that could plausibly happen in real life, if we had the technology to do it.
From this, it shows that most machines in Monifactory are usually physically plausible, just that it requires some magical material to break the laws of physics initially, but from there, it follows as expected. For example, the Microverse Projector probably isn’t possible, but it’s only really the microverse part that’s impossible. If we could make a miniature universe, it’d be perfectly possible to build a miner to mine that microverse for materials.
Sculk is some sort of fungal-like thing that can spread (and even convert) stuff by feeding on experience. Additionally sculk thrives in the cold and because sculk is a magical fungus, it thrives at cold temperatures. It’s favorite temperature is absolute zero because why not. It’s some sort of magical fungus that loves darkness and caves, so it must love the cold.
The Hypogean Infuser is a machine that encourages sculk to grow and transmute items together. It does this by chilling the sculk down, the closer to absolute zero the better. Then it feeds the sculk with large amounts of experience to force it to grow on things it normally doesn’t. The more experience its fed and the colder it is, the more varied the items it can grow on.
One possible explanation for sculk requiring such extreme conditions to grow on somethings could be that sculking something multiple times becomes harder and harder because the sculk already grew everywhere it could at the warmer temperature. For recipes that don’t involve pre-sculked stuff ¯\_(ツ)_/¯, something something bad substrate for growing.
In order for the Hypogean Infuser to work it must first chill the growing chamber down, this takes time and requires a constant amount of power. The amount is dependent on the final temperature it’s trying to reach. If the Infuser runs out of power it’ll instead warm up back to room temperature.
The Infuser also requires a source of sculk to actually grow with. Normally this requires some seed item like a Sculk Catalyst or whatever’s expensive in Moni, but the Infuser can keep its initial sculk alive by feeding it with experience. The amount of xp the sculk requires is dependent on the temperature, colder requires more because the sculk is more active. If the Infuser runs out of xp, the sculk will die, and it’ll require another seed item.