Wanted: A Better Shower Controller
14th February 2015
David Friedman speaks for all right-thinking people.
Taking a shower this morning I was struck, not for the first time, by how badly designed the mechanism for controlling the temperature is. Turn it a little to the right and the shower is uncomfortably hot. Turn it just a little back to the left and it is uncomfortably cold.What is going on is pretty clear. The controller maps its position to the amount of hot water in the mix in a roughly linear fashion. All the way to the left is straight cold, all the way to the right is straight hot, any intermediate position is a proportional mix.In practice, almost nobody wants a cold shower or, unless the temperature of the hot water is pretty low, a straight hot shower. What almost everyone wants is a mix within a fairly limited range—say from .6 hot to .8 hot—with the exact range varying both with the temperature of the hot and the cold water and the preferences of the person taking the shower.
February 14th, 2015 at 08:37
My place has a thermostat shower mixer, like everyone around here (Finland) has had for years. The temperature is set with one control, the flow of water with another. When you take a shower, you only need to open the water flow, and in a moment the temperature is right.
(Unless the wife has messed up the heat control, of course – here my innovation would be a fingerprint or facial recognition for who’s taking shower and adjusting default temp accordingly – a bit like those automatically adjusted seats in cars that know who’s key is used to start it up).
The temperature control usually has a click switch at 38°C (100.4°F, slightly above body temperature) so that you cannot accidentally scald yourself, but you can bypass it if you want really hot water. Typically the faucet is set so that the coldest you get out is 10°C and hottest 55°C. The temp control is not linear, of course; much of the movement varies temp in the 30-40 °C range.
I didn’t remember not having this is still a problem in America.
February 16th, 2015 at 05:12
I wouldn’t say it’s a problem, but I don’t recall ever seeing such an arrangement in America.