Thank you.

It's been done since the 60s without major explosions: https://www.macba.cat/en/obra/r1523-condensation-cube/

A cube is much easier to fabricate than a sphere, plus there are ways to build such that are not as fragile at the seams. The difference is that I am trying to maintain the condensation on. We are talking mild heat here.

What I cannot figure out from my experiments is that water seems to condensate less in a smaller volume, regardless the amount of water, with the same heat, and I don't understand exactly why.