I just visited some web galleries of bathroom remodelers in the US, and it looks uncommon to have external shower fixtures. They tend to bury as much of the fixture as possible in the wall. From the photos, I don’t get the impression they are using thermostatic mixing valves. But it’s hard to tell. Can anyone confirm or deny?
I think I might favor external fixtures because they tend to be much cheaper and also more easily servicable.
These days most usa bathroom fixture I’m familiar with have a single temperature control that you set and it keeps the temperature steady at the set temperature even if the water pressure varies. Is that what you are wondering about?
Yeah, kind of. I’m glad to hear they have that capability. But note that there are some non-thermostatic designs that come close to achieving the same effect. Those have a memory of sorts, where they know you want X volume of hot water and Y volume of cold water. Then if the pressure in one drops or increases, the valve will adjust the other line ensure the hot and cold have the same ratio regardless.
That’s pretty good. But it assumes the hot water and cold water are each at constant temps. So imagine if you get to near the end of a hot water tank supply, the hot water will gradually become colder. In that case, a thermostatic valve will open the hot even more to chase the temp you want. Whereas the pressure balance style will not. Perhaps more importantly, the pressure balance style does not counter the fact that the hot line will be initially cold since the hot water cooled down while sitting in the pipe. So you have to fiddle with readjustments until the hot pipe is maxed out.