The Better Vents Mod lets you make vents out of any resources and coolers only can be made out of metals. Steel vents now have 250 hit points instead of 100.
The total hit points depend on what you use to make it.
Better Vents Mod Review
If it bothers you that vents and coolers are so noticeable, the Better Vents Mod lets you choose the same stone as your walls for a better looking colony.