The energy wasted isnt just the electricity to run the pump 24/ its the heat radiated off the pipes. in the winter it helps warm your home but in the summer its just adds to your discomfort and AC bill:('
Here I have about a 40 foot n from tank to bath. I rarely wash my hands in warm water unless someone else was already using it. but do cold hands matter probably not. for me
dont want a cold shower though:( So I let it run a bit before getting in.
over the 50 + years this home has been here thats probably a LOT of water and gas wasted:( Although I havent lived here the entire time, just 33 year or so.
I would install the circulator pump with a button AND run always and timer setting. then use it however works best. if your showering a quick button press with a few minute wait while you get stuff together probably doesnt matter...
while waiting for warm water to wash hands might myself I would make do with chilly water at sink.
but a system with button, timer, or always on leaves the customer to decide whats best for them and can be canged accordingly