Comment by Retric

Not all COTS are equal. There are plenty of off the shelf controllers built for boats that are designed to handle wet environments such as might be found in an enclosed space where people are exhaling water vapor etc. They don’t however cost 30$ nor do they cost anything close to the R&D required to make an equivalent product.

Of note they might not have condensation in normal conditions, but condensation is exactly the kind of thing that results in cascading failures when just one seemingly minor thing fails.