Stuff I want

[andrewducker]

Why is it that you can't get a bathroom tap (or shower controller) that you can calibrate to an exact temperature?

Why can't I say "I'd like my shower to be 43 degrees" or "my bath should be 49 degrees"? That way, it could deal with the variance of incoming water, mix it to the desired temperature and deal with the fact that me and my various living partners have always liked things at different temperatures.

I mean, sure, in the past it would have been a real extravagance - but nowadays a switching valve with microprocessor should be peanuts!

Comments

[davidcook.livejournal.com]

Ohhh yes. One of my pet peeves about plumbing. I've always thought there should be a flow control and a temperature control, and good mixing.

(Bathroom sinks around here seem to have one of two possible arrangements - separate hot and cold taps with separate spouts, or separate taps with a common spout - except the spout actually has an internal division to keep the hot and cold water separate. Why ? The hot water is too hot by itself to wash hands with, but in mid-winter, the cold is too cold. I want mixing, darnit !)

You know.

[ekatarina.livejournal.com]

*I* want a bathroom like that as well.

Heated towel racks, exact bath temp, exact shower temp, warm floor, fresh breeze, hot chocolate machine built in.

When *I* win the lottery,...


Sigh.

Wishing you well,

Ekatarina, who is also living in student digs

Re: You know.

[andrewducker]

The thing is that all of those things can be bought now _except_ for the temperature-controlled flow-control. And I want to know why not!

[miramon.livejournal.com]

It's a pressure problem. You can't afford to let the high-pressure cold water back up into the (relatively) low-pressure hot water system. Quite apart from anything else, if it slows/stops the flow of water through the boiler there's a risk of the boiler exploding. A power shower will pressurise the hot water, so if you want to run your tap off the same pump (assuming you have a tap rated to that pressure) you should be able to hook in a thermostat (provided you were willing to give up consistent pressure - you can't have both). There's probably some reason why that's a bad idea too.

[andrewducker]

Now, I know fuck-all about valves and plumbing, so I'd appreciate being corrected if I'm talking bollocks but:

Surely you could have two valves, one for hot and one for cold, they could both let through differing amounts of water, at the same pressure, so that they mixed to produce the correct temperature.

So if you have high pressure cold water and low pressure hot water, you lower the pressure of the cold water and let less through, so that it mixes with the hot to produce the right temperature. Obviously you'd have to allow the pressure to vary, but provided the hot and cold both had reasonable amounts of pressure in the first place you could leave enough leeway to ensure that this wouldn't be a problem too often.

[miramon.livejournal.com]

Actually, more likely than the boiler exploding is that cold water will force its way back, through the hot water system, to the cold water tank that feeds the hot water system. There is generally (AFAIK) nothing in place to prevent such a blow back, so the tank will just overflow, probably dumping boiling hot water into the roof space.

[miramon.livejournal.com]

I don't know enough about plumbing to be able to say how feasible it is. It's probably quite possible, except that every valve and whatever on the market is made on the assumption that it's going to be installed into the standard situation. Other countries have different systems and may not have the problems we have.

However, I believe that the sort of constant pressure valve you describe (e.g. able to reduce pressure downstream to a set point, no matter how high the pressure on the upstream side, and able to cope with very variable pressure levels within a space of seconds) is a non-trivial problem.

[stillcarl.livejournal.com]

I can hold my hand in the out-flowing water and adjust the taps till the temprature's how I like it. This doesn't cause anything to explode, so why should a thermostat doing the same thing be any different?

I'd think the real problem would be it wouldn't know what to do when the hot water ran cold.

[drplokta]

You can get thermostatically controlled showers, if you pay a bit more, and your plumbing is up to it. I doubt there's enough demand for thermostatic mixer taps for it to be worthwhile.

[andrewducker]

Got link?

[andrewducker]

Well, you could set it with upper/lower limits. So if it got too cold or too hot it would shut off, or divert the water elsewhere.

[miramon.livejournal.com]

Googling on "constant pressure valve" comes up with several expensive and patented solutions (for things like chemical plants) along with a comment saying that domestic plumbing could achieve this with a variable speed pump, only it's too expensive. So yes, if you win the lottery, you can have perfect hot water.

Re: You know.

[figg.livejournal.com]

http://www.trevishowers.co.uk/quickguide.asp

Like this ?

Features:

Temperature lock allows safety stop temperature to be set individually, at 40°C, 43°C, 46°C or 48°C
Precise temperature control
Flow control handle turns through 180° allowing fine adjustment
High water flow rate
 
  
 
 

Re: You know.

[figg.livejournal.com]

ps: I googled for exact temperature shower.

Found out the type of valve used is a "thermostatic shower valve"

[derumi.livejournal.com]

We have a pressure valve system that keeps the temperature steady, dependent on how much hot water's remaining in the boiler. So you can run the shower upstairs, have someone flush downstairs, and have the washer kick in, all without getting burnt or froze. You might, however, end up with a trickle of water depending on what's all going on. I think we installed that system installed about 10 years ago. Shouldn't be too hard to have a shower controlled by a thermostat nowadays.

[drplokta]

Can't give link to exact pages due to irritating use of frames, but go browse around http://www.tritonshowers.co.uk/

Re: You know.

[drplokta]

That's a safety-stop. It won't go over the temperature you set, but it may go below it.

Re: You know.

[andrewducker]

I'd like to state that this is not student digs!!!1 (this is Lilian. This is a nice middle class flat!)

[avatar.livejournal.com]

My parents have a shower/bath where you can control the temperature. At worst, it takes a few seconds to work and the stream needs to be hard enough (which is pretty average).

[miramon.livejournal.com]

Because it's kind of hard to suspend a thermostat under the tap. Quite apart from anything else, you'd find it difficult to wash your hands without getting messed up in the wires. But if the sensor is inside the tap/spout, it's also inside the pressure system.

[andrewducker]

Wouldn't have to be. It could be after the mixing point, before it comes out of the tap.

[stillcarl.livejournal.com]

Froogle's good - Froogle give pictures...

http://froogle.google.com/froogle?q=%22thermostatic+shower+valve%22&btnG=Search+Froogle

http://froogle.google.com/froogle?q=%22thermostatic+bath%22&btnG=Search+Froogle

I think whatever the technical problems are, they've been solved...