[roncesvalles]

On a tangent but I still don't know why we don't have showers where you just press a button and it delivers water at the correct temperature. It seems like the simplest thing that everyone wants. A company that manufactures and installs this (a la SolarCity) should be an instant unicorn.

[yencabulator]

For what it's worth, Northern European showers typically have two independent controls: temperature and flow. Leave the temperature at what you think is good, and either wait a moment for hot water to reach the end of the pipe or install a recirculating loop.

[pepoluan]

What's "correct" for you might not be "correct" for others. Furthermore, your owb definition of "correct" changes depending on circumstances; sometimes you want it hotter, sometimes you want it colder. Sometimes you want to change it partway through.

How do you calculate for that?

Back in the 90s, Fuzzy Logic was thought to be the solution. In a way, yes, but only for niche/specialized purposes, and they still have to limit the variables being evaluated.

[roncesvalles]

How about it uses temp sensors to read your skin temp (if that's the variable that matters, idk), and some mechanism for "feedback" after an initial guess? It's all implementation details.

[lazide]

Water + electronics/power typically isn’t very durable, or reliable. Most people want their shower valves to work at least 20 years, ideally 50-100.

[pepoluan]

Can be mitigated to a degree by separating the (cheaper) sensors and the (pricier) logic.

But then it will become a tradeoff of complexity vs longevity.

[lazide]

Nah, because it would still need servicing.

And why? There are reasonably well done, low maintenance, temperature balancing valves out there.

And they do typically last 20+ or more years.