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A manifesto on shower temperature control

benholmen.com

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Re: A manifesto on shower temperature control

#101

Post by vl »

scottlamb wrote: post #66
achenatx wrote: post #4

I have one of these grohe thermostatic valves. You can set the temperature and then use a push button to turn the shower on. The temperature is always set correctly as the on/off is separate from the temperature control. A majority of the range of the dial is usable. We still use cold water for cleaning the shower, or when you want a cold shower. During the shower, I have it set to hot, then slowly turn up the heat.…

I have a Gröhe thermostatic valve which came with the house. It's somehow broken such that you can't get the water as hot as advertised unless the dishwasher is running (?). And it's installed behind tile, so we can't just get a plumber to come in and replace it; we have to also line up someone to re-tile the shower immediately afterward. We also have a pair of Gröhe sinks. We had to replace all four expensive, propr…

All thermostatic valves have cartridges that eventually wear off and need to be replaced. Cartridge is accessible from outside by removing the handle held by the side screw (handle can be stuck and hard to remove) and then unscrewing the cap. Remove the cartridge, look at the part number and buy the replacements at Amazon. Obviously cut off water to the shower first.

Also handle has a small button on the bottom which blocks it from going into super-hot range. If you need hotter than normal water, press and hold this button while rotating the handle. (Handle is supposed to be calibrated when installed so digits on the dial match water temperature, but nobody does that)

Re: A manifesto on shower temperature control

#102

Post by josephg »

Macha wrote: post #96
gorgoiler wrote: post #45

As a friendly heads up to anyone exploring this space — temperature control is a complex dynamic between many components, chiefly the mixing valve, any local thermostatic dampers in the valve (rarer, but definitely a feature of high end mixers), and the source of hot water itself . Mixer taps are not simply mixing hot water at temperature H and cold water at temperature C. The temperature H which your hot water sourc…

This is also the case for electric showers though, where the shower itself contains the heating element and heats its own water, rather than taking arbitrary feeds of hot and cold water.

The shower doesn't need an internal heating element. All you need is an electric control system, which dynamically monitors the temperature coming out of the shower head and constantly adjusts the mix toward a set temperature.

I have a feeling these have existed for a long time in Japan.

Re: A manifesto on shower temperature control

#103

Post by vl »

dclowd9901 wrote: post #87
sintezcs wrote: post #7

Earlier quoted context omitted.

I also have grohe thermostatic valve and enjoy it a lot! Worth every $ spent.

Same, nothing but good from my experience. Just a bit finicky to install like most European hardware and fixtures. Oh and their instructions are pictures only and hilariously obtuse.

Well, you can get Chinese thermostatic valve for few times cheaper.

Re: A manifesto on shower temperature control

#105

Post by rconti »

2 side-rants:

* Physical shower controls themselves. The typical US single-handle shower control is awful. Maybe I'm stupid, but it's never intuitive to me which side is hot and which side is cold. Much of the time the handle is pointing down, so you have to visualize an arrow extending through the top of the control, pointing left (hot) when the handle is on the bottom right. Sometimes they point entirely different directions, or the rotational positions of off, cold, hot make no sense at all. As I write this, it occurs to me that it's probably obvious that cold is always closest to "off", and "full on" is always full hot, but I'm over 40 and this has never occurred to me until now, so it can't be just me. Anyway, for whatever reason, when they're not labeled, i've never been able to 'remember' which side is hot and which side is cold. Again, maybe it's just me, but I've never had any other such dyslexic tendencies outside of faucet control. I think in my head "C" is on the left because it places C and H in alphabetical order?

* Tankless hot water heaters. I want to like them. I've had them in my last 2 houses, covering the past 12 years. I can't imagine buying a water heater with a tank, but... The (central) tankless heaters take 15 seconds to turn on, and the water takes forever to make its way across my tiny house. So much water and time is wasted. And they shut off after some minimum flow rate. So if you try to use 'too little' hot mix (hot water heater set 'too high' or cold water input too warm, say, in the summer), the water heater decides to click off.. which you only notice 20 seconds later as the hot water trickles out of the pipes, and now you have to wash, rinse, repeat the whole awful cycle of turning the handle to full hot, waiting for hot water again, turning it down, but hoping you didn't turn it down too far. I've turned the hot water heater down as low as it'll go without much noticeable difference in this behavior in either house. Perhaps because the minimum flow rate actually depends on the setpoint of the hot water, which would make sense. It's worse in the summer. It's only a problem I have in 10% of my showers, but it drives me nuts.

Re: A manifesto on shower temperature control

#106

Post by sideshowb »

fy20 wrote: post #36
MR4D wrote: post #23

Earlier quoted context omitted.

Now I want one of those for my car!

If you car has an Eco or Power or Sport mode this is probably what it does. On my Toyota, Power mode makes the accelerator more sensitive and Eco mode makes it less sensitive (which is great for snow). Flooring it is the same, regardless of the mode.

I haven't owned a car with them, but I thought those modes were to control when the gear shifts happen. Sport will optimize acceleration while eco will change up sooner to save fuel

Re: A manifesto on shower temperature control

#107

Post by nemetroid »

Kim_Bruning wrote: post #18
stdbrouw wrote: post #6

Earlier quoted context omitted.

Huh? Regular thermostatic valves do not provide perfect regulation but they do in fact provide a fairly stable output temperature regardless of cold and hot water temperature, by entirely mechanical means. I have a cheap IKEA shower control and output temp is stable for the full duration of my shower even though cold nor hot water supply is stable due to a shower drain heat recovery unit. The article is mainly about…

Are cheap thermostatic shower mixer controls not so common outside middle-of-europe? This is the one with one grip that lets you set the temperature, and the other sets the flow rate. It'll (try to) hold the output temperature steady even if the input temperature varies a bit.

Indeed this solution has been standard in much of Europe for decades.

It seems to have had slower uptake in the US. Donald Norman’s ”The Design of Everyday Things”, 2013 edition, contains this passage in a list of different faucet designs (p. 151):

> Control temperature and rate of flow. Use two separate controls, one for water temperature, the other for flow rate. (I have never encountered this solution.)

I e-mailed Don about it a few years ago, and by then he had encountered it.

Re: A manifesto on shower temperature control

#108

Post by scottlamb »

vl wrote: post #101
scottlamb wrote: post #66

Earlier quoted context omitted.

I have a Gröhe thermostatic valve which came with the house. It's somehow broken such that you can't get the water as hot as advertised unless the dishwasher is running (?). And it's installed behind tile, so we can't just get a plumber to come in and replace it; we have to also line up someone to re-tile the shower immediately afterward. We also have a pair of Gröhe sinks. We had to replace all four expensive, propr…

All thermostatic valves have cartridges that eventually wear off and need to be replaced. Cartridge is accessible from outside by removing the handle held by the side screw (handle can be stuck and hard to remove) and then unscrewing the cap. Remove the cartridge, look at the part number and buy the replacements at Amazon. Obviously cut off water to the shower first. Also handle has a small button on the bottom which…

I will check that out, thank you!

We did have a plumber look at this valve while here for something else, and he neglected to mention that...

Re: A manifesto on shower temperature control

#109

Post by xuhu »

sideshowb wrote: post #106
fy20 wrote: post #36

Earlier quoted context omitted.

If you car has an Eco or Power or Sport mode this is probably what it does. On my Toyota, Power mode makes the accelerator more sensitive and Eco mode makes it less sensitive (which is great for snow). Flooring it is the same, regardless of the mode.

I haven't owned a car with them, but I thought those modes were to control when the gear shifts happen. Sport will optimize acceleration while eco will change up sooner to save fuel

I hope Sport mode changes both rpm limit and pedal response.

Re: A manifesto on shower temperature control

#110

Post by waste_monk »

morepork wrote: post #99
deathanatos wrote: post #89

Earlier quoted context omitted.

"Safety" is also what my guy said. The problem is that in isolation the answer doesn't make any sense : why should I be heating water up to then re-mix cold water? Is that not a waste of energy? The fuller answer, I think, is that the "raw" hot line additionally goes towards uses that can take scalding water, one or more of the dishwasher and the laundry, depending on whether you have either or both of those in your…

Storing the water at a higher temperature effectively increases the capacity of the tank. Also the stored hot water has to be above a certain level (~60 degrees) at least some of the time otherwise it won't prevent any bugs growing in it.

Yep... particularly Legionella Pneumophila and friends which can cause Legionnaire's disease.

I was taught as a child NEVER to use a hot shower from a water tank or drink warm water from the tap after a sustained power outage until the tank has had time to come back up to it's normal temperature... Legionnaire's can straight-up kill you via pneumonia.

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