Can someone explain why on earth some
shower controls turn up the cold water
100% - then - gradually start turning
up the hot water ???? (ie. you need to
twist them in one direction to first
get cold going, up to 100%, then it
starts to allow hot water to mix)....

This seems like a colossal waste of
water (since you're running the cold
valve wide open at max pressure) -
vs. the pull out type control where
you can control pressure & hot/cold
mix by pulling out for pressure and
twisting for mix).

Which brings us to HVAC systems - i've
seen building "environmental" controls
that run the AC continously - and when
a target temp is reached - instead of
turning off - they turn on the heater !!

WTF !???? wouldn't it make more sense to
just turn off the air conditioners ??
(instead of turning on the heater - while
the air conditioner is still running).

hell of a way to waste energy.

is there some thermodynamic reason behind
this (on the surface) idiotic logic ???