Tankless water heater is one of the best solutions.
Tape a thermocouple to the pipe and use a data logger?This is the basic idea.
Simplest option, use a logging multimeter like a Fluke 289 or an EEVblog 121GW, leave it logging for a week and then dump the data.I don't like the idea of leaving a bit of kit like that lying around - besides the head of the household won't know how to access the information and I do not want to get into data retrieval duties. Having an App with Bluetooth or WiFi connectivity is the direction that makes sense, especially when accessing the information needs to be, essentially, in real time - typically within an hour of occurrence.
Less simple option, use a single board computer like a Raspberry Pi and have it log onboard or have it send the data to another computer over wi-fi.This was my thought for a DIY - but I don't really have time for development. If someone has already built something and shared it, I could manage construction.
I guess you will need cooperation of the residents, or they might simply disconnect the logger.<Answered above>
But if the residents are cooperative, why not simply ask them who used all the hot water?They lie
Do be aware if your Powerco can control HWC's remotely it may be just not being heated.
3. The principal issue is determining how much hot water is being used - and by whom.
Temperature alone won't tell the amount of water. For that, you'll need a water calorimeter, which accounts for both the water temperature and the debit.Absolute accuracy is not required - simple relative comparison will suffice for the basic requirement. When and how long is enough for them. I was considering the temperature gradient idea as an extra indication.
And that still won't tell who used all the hot water, unless you add webcams at the girls college dorm showers. ;DThat is not a problem I have to address. If I simply make the times known, the head of the household can work that out.
The actual flow is a secondary issue as it seems the main offenders simply turn the hot tap on full and regulate with the cold.
the head of the household has raised the request.
but I don't really have time for developmensurely you can use the development time to your advantage to get out of other ,less intresting duties.
The bathroom repair bills after she causes anything not solid plastic, metal or glazed to peel or blacken with mould can exceed the gas bill.Tankless water heater is one of the best solutions.Until the teenager daughter will brake daddy bank causing astronomical gas bills.
Why would that happen with an instant hot water heater but not with a hot water tank?The bathroom repair bills after she causes anything not solid plastic, metal or glazed to peel or blacken with mould can exceed the gas bill.Tankless water heater is one of the best solutions.Until the teenager daughter will brake daddy bank causing astronomical gas bills.
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My idea is to have a temperature sensor mounted on the main hot water pipe before it splits off to the various taps, with temperatures recorded at regular intervals, including timestamp. This will show when hot water was used - and for how long.
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4. Suggestions.....
Er, isn't that obvious. So many of them only stop showering when the water runs cold. Continuous hot water means they steam up the bathroom until it falls apart. If you have a really effective extractor fan you can stop it, but in the winter that means you are exhausting a lot of expensively heated air, so going wild with the extractor was more for when we lived in a hot and super humid climate.Why would that happen with an instant hot water heater but not with a hot water tank?The bathroom repair bills after she causes anything not solid plastic, metal or glazed to peel or blacken with mould can exceed the gas bill.Tankless water heater is one of the best solutions.Until the teenager daughter will brake daddy bank causing astronomical gas bills.
Put a fake webcam high up in the shower stall. Put a sign next to it that says, "Webcam activates 10 minutes after water is turned on"... Have a motion sensor that turns on a red LED on the "cam" after 10 minutes of motion.
I'm not sure what plumbing fixtures you have but that's not generally how it works. The flow is mostly regulated by the shower head.Which is usually the easiest/cheapest way to balance hot water demand, replacing the tank with a larger unit is $$$ but replacing the shower head (or changing its restrictor) with a very low flow will also balance the supply vs demand.
My idea is to have a temperature sensor mounted on the main hot water pipe before it splits off to the various taps, with temperatures recorded at regular intervals, including timestamp. This will show when hot water was used - and for how long.The "proper" industrial solutions work offline and are easy to deploy (would suggest putting the thermal sensor at the grey water exit, as temperature rise will then be a proxy/estimate of the flow rate at the time) but are $300/400/500 units. Solution is to have the people in question work with each other.
4. Suggestions.....
Exhaust fan, smart switch, humidity sensor, and home automation are the way to go. Throw in a door stopper to keep the bathroom door open when not in use; it'll help save a few dollars on the running costs of the whole-house humidifier during winter.Er, isn't that obvious. So many of them only stop showering when the water runs cold. Continuous hot water means they steam up the bathroom until it falls apart. If you have a really effective extractor fan you can stop it, but in the winter that means you are exhausting a lot of expensively heated air, so going wild with the extractor was more for when we lived in a hot and super humid climate.Why would that happen with an instant hot water heater but not with a hot water tank?The bathroom repair bills after she causes anything not solid plastic, metal or glazed to peel or blacken with mould can exceed the gas bill.Tankless water heater is one of the best solutions.Until the teenager daughter will brake daddy bank causing astronomical gas bills.
Taking your second point first... There are only 3 locations in the household that have hot water: the bathroom, laundry and kitchen (there is only 1 of each). The bathroom is the main area and while it does have 3 taps (shower, bath and basin) they are considered collectively in regards to hot water usage. The "laundry" is an alcove setup and we can pretty much ignore hot water usage there as it is almost never used (cold water machine washing only) and the kitchen will never use hot water while someone is in the shower - or there will be blood...
My idea is to have a temperature sensor mounted on the main hot water pipe before it splits off to the various taps, with temperatures recorded at regular intervals, including timestamp. This will show when hot water was used - and for how long.
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4. Suggestions.....
I assume your "main hot water pipe" is where hot water exits the water-heater or very near it. I will call it "main pipe" as abbreviation.
Depending on how your plumbing is routed, "main pipe" may not be the best spot. You have more factors to consider -- (1) hot water still in the system when water tap is turned off and (2) where the hot water is going.
Easy way to clarify is to lay down a scenario: Let just say, you are taking a shower military-style (at or under 2 minutes). 5 minute after your shower, someone turn the hot water in the kitchen for 1 minute to rinse a cup. Now the "main pipe" is re-filled with freshly heated water again before it was cooled measurably after your shower. Say another 10 minutes later, someone washes his/her hands in the second bath-room, now the main pipe is re-filled with hot water again. So on, each time the hot water is used briefly, the "main-pipe" refills with hot water and it may not cool for a very long while.On your first point, the "main pipe" attached to the heater (which is outside*) is not insulated**, so ambient air temperature will be a factor in cooling rate (so will rain for that matter). This assists in the more reliable detection of water flow stopping - since all that is really necessary is to see the temperature start to drop by a characteristic amount, determined experimentally.
The best position would be at the shower-head, there temperature alone will work. Otherwise, you have to know the cooling time of still-water in the pipe, and consider any "branching" to another outlet.Shower is the main focus, but bath cannot be excluded as it does get used. Fitting a sensor to the shower head is just not practical and will certainly have an "accident" in very short order. Same for the bath. A single, common point does have its shortcomings, but it still has sufficient merit for the required purpose, not to mention ease of implementation. Trying to access the pipework directly for each tap or even room would require crawling under the house which is undesirable (to say the least) as 1. The only access point is almost at the opposite side of the house; 2. The clearance between the floor and ground at that end of the house does not allow kneeling - and while I have no idea what it is like directly under the bathroom, it can only be worse and 3. The ground has significant bits of building debris which you would have to crawl over.
Note also, if the shower room is high such as in the 2nd floor while the water heater is in the basement, there are a lot of pipes holding the not-running but still hot water. The hot water will rise to the highest point it can even if the hot water is not running.Not really an issue. Single storey house where the difference in height of all hot water piping would be around 6' (1.8m). (I don't count the height from breech to shower head.)
Edited to add this: For cooling time, you also have to consider ambient temperature around the pipe. I am sure it will change a lot on a hot day verses the cool evening after sun down.This is something I have already considered. A single sensor is the simplest, quickest and cheapest to implement - and it may be all that is needed to achieve the fundamental objective - but for something more accurate, I have considered one system with 3 sensors and another with 4.
Put a fake webcam high up in the shower stall. Put a sign next to it that says, "Webcam activates 10 minutes after water is turned on"... Have a motion sensor that turns on a red LED on the "cam" after 10 minutes of motion.
Uh huh, nothing worse than "lying" to close people. Once they figure out the lie (which would probably happen pretty fast), they'll stop trusting you or even listening to you in any serious way altogether.
There are many fish hooks in a problem like this.
1. Already mentioned that Powerco's manage their demand by switching water heating loads.
2. Hot water storage capacity is insufficient for the demand.
3. Mum did a large load/s with the washing machine that day.
4. Heating regulation settings are just too low for the capacity/demands.
5. The plumbing installation can be substandard with long runs to each HW draw point wasting HW just supplying each outlet. Smart systems use a constant return system to have HW instantly on tap.
6. While there are often local regulations as to how hot water heating can be set these can be overridden with the installation of a tempering valve at the HWC outlet that mixes cold to maintain a constant and safe HW temp for consumers.
Addressing any one of the above can have problems miraculously vanish.
Engage a smart/experienced plumber for a fix.
Just cut to the chase an fit a timed shower valve,whoevers hogging te hot water will soon get bored of pressing the button every 20 secondsYeah... nah.
... ... ... The "proper" industrial solutions work offline and are easy to deploy (would suggest putting the thermal sensor at the grey water exit, as temperature rise will then be a proxy/estimate of the flow rate at the time) but are $300/400/500 units.1. Grey water exit very difficult to access.
Solution is to have the people in question work with each other.That doesn't work when you have selfish people that feel entitled that lie and can't be challenged as nobody has stood at the bathroom door with a stopwatch. I am trying to enable the introduction of some hard evidence in the conversation to change that. Simple time of day and duration could be all that is needed.
Standing someone at the door with a stopwatch is the real solution, and what solves it 99% of the time. Asking the internet to optimise a low cost tech solution match to the extremely specific requirements (fed slowly) is pretty rude when the time spent doing that for all involved is going to far outweigh the "savings" for the household. That the ""household" won't see any of those costs is part of the problem, they need to work this out and see the real costs of doing so (be that only showering when someone else is present to confirm the duration).Solution is to have the people in question work with each other.That doesn't work when you have selfish people that feel entitled that lie and can't be challenged as nobody has stood at the bathroom door with a stopwatch. I am trying to enable the introduction of some hard evidence in the conversation to change that. Simple time of day and duration could be all that is needed.
To set one fundamental detail: The hot water system capacity IS adequate for the number of people in the household, so long as people make reasonable use of it in their ablutions.According to your arbitrary belief of "adequate", as clearly multiple residents believes it is not adequate:
What HW capacity currently exists and what is the temp it is set to ?There are many fish hooks in a problem like this.
1. Already mentioned that Powerco's manage their demand by switching water heating loads.
2. Hot water storage capacity is insufficient for the demand.
3. Mum did a large load/s with the washing machine that day.
4. Heating regulation settings are just too low for the capacity/demands.
5. The plumbing installation can be substandard with long runs to each HW draw point wasting HW just supplying each outlet. Smart systems use a constant return system to have HW instantly on tap.
6. While there are often local regulations as to how hot water heating can be set these can be overridden with the installation of a tempering valve at the HWC outlet that mixes cold to maintain a constant and safe HW temp for consumers.
Addressing any one of the above can have problems miraculously vanish.
Engage a smart/experienced plumber for a fix.
While all those points are valid in their own right, you have completely missed the primary objective - which is to identify WHO is using up the hot water. If I can identify the time and duration, the head of the household has told me they can then identify who. If I can add an indication of flow rate, then this would be icing on the cake.
As for problems miraculously vanishing - I would take that with a huge grain of salt. From what I have gleaned, all that will happen is the culprit(s) will hear "unlimited hot water" - no matter how you phrase it - and the problem simply changes scale. The problem needs to be brought to heel, not encouraged.
Plumber expense is not on the table.
Using only one sensor will not work I think. One quantity (temperature) there is too much lag due to the thermal mass of the pipe and water inside it.Think about that for a second.
I expect false imprisonment because your datalogs will show a longer cooldown time for the water pipe, long after the shower is stopped.
It seems odd that knowing the time of day when massive hotwater usage occurs will identify the culprit. Because you probably already have that information and still can't figure it out:Determining the "sequence" as you put it is not a problem I have to solve. The householder has a means to determine that. This means can identify occupancy time of the bathroom, but not water usage.
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But if you don't know the sequence, then how will knowing the times of temperature change help at all?
ie: If the sequence of people showering is A, B, C, D, E and C & maybe D are always complaining about cold water, then it follows that B is your problem.A basic assumption - and very wrong.
There is only one thing for it, you need to get evil on their arse. >:D
Determining the "sequence" as you put it is not a problem I have to solve. The householder has a means to determine that. This means can identify occupancy time of the bathroom, but not water usage.
So the householder knows who is in the bathroom and exactly when they enter and exit. Yet this same householder cannot tell if the water is running or not?They have a security camera that covers a section of the hallway that must be traversed, so they can see who goes in and when. It does not listen for water.
Good luck with your project, but I doubt it'll provide much useful data beyond what could be gleaned by some intelligent observation.So your criticism comes from the unrealistic expectation that someone is always waiting and watching every day over the whole time someone might just use the bathroom. Geez - it's not like they might actually have other things to do, like going to work.
Pipe temperature is a poor indicator. Even just washing your hands carefully with minuscule flow rate is enough to bring the pipe to the maximum temperature. Then it starts to cool slowly, during next 5-10 minutes or so, and you have no idea whether 0.1 or 10 liters was actually used.Certainly pipe temperature isn't ideal - but it is extremely convenient.
The only idea you get is distinction between running the hot water for a short time (minutes) or long time (tens of minutes), but still no idea about the flow rate.
What next, a shaft encoder to calculate how much toilet paper is being consumed and by whom?That is another sore point in this household. I'll say no more on that.
Dedicate your resources to defining a heating system that meets the needs of the users, rather than farming data on people whose only crime is using soap.So you consider the selfish use of all the hot water for the household and then deny any responsibility for it as an honourable activity?
This might be an interesting project, but are you involved in someone elses witch hunt?It's not a witch hunt. The guilty party is well known, but they are bold and brazen in their denial. I am looking to provide definitive evidence that they cannot deny.
So the householder knows who is in the bathroom and exactly when they enter and exit. Yet this same householder cannot tell if the water is running or not?They have a security camera that covers a section of the hallway that must be traversed, so they can see who goes in and when. It does not listen for water.QuoteGood luck with your project, but I doubt it'll provide much useful data beyond what could be gleaned by some intelligent observation.So your criticism comes from the unrealistic expectation that someone is always waiting and watching every day over the whole time someone might just use the bathroom. Geez - it's not like they might actually have other things to do, like going to work.
The combination of recorded image and data allows for post event review. If someone complains, then pull up the temperature data and check the camera footage for the times indicated.
Please consider the practical aspects of addressing a problem before being so dismissive.
Set the timer for something more realistic, say 5 minutes, with a 5 minute delay before it can be triggered again. A push-button, solenoid valve, a DC PSU, microcontroller and a push-button with an IP rating of 67 will do.Just cut to the chase an fit a timed shower valve,whoevers hogging te hot water will soon get bored of pressing the button every 20 secondsYeah... nah.
That is going to piss off EVERYONE who uses the shower. Revolt guaranteed.
There is far more detail to the background that is not appropriate to share here, but let me just say that anyone who wishes to criticise the exercise for social reasons is doing so out of ignorance.
For the technically curious, this lot is being processed by a Raspberry Pi, running Raspbian Linux. The Dallas DS18B20 temperature sensors are connected to the GPIO headers (3V3, Gnd and data, which is on GPIO4) and read by the kernel w1_therm module. This then punts the output to a logfile which is read by a bit of Perl that converts the tabular data to a graph, and builds a .png of it before uploading it to the server. It's not perfect. For some reason every now and then the sensor returns a "doesn't respond to CONVERT_TEMP" error and a -ve temperature. This is smoothed out by checking the CRC and re-reading if necessary.
But you didn't NEED to know about the camera. You were already told that the head of the household had the means to determine the required information. Even I didn't need to know exactly how they were going to do that.Please consider the practical aspects of addressing a problem before being so dismissive.Kind of hard to do since this is the first time you've mentioned the camera.
Now that we know this, your precise timestamping of pipe temperature makes more sense.But, does having this knowledge change the way to approach the problem any differently?
So another idea is a vibration sensor attached to the pipe listening for water flow. This will give a faster response than temperature.Now THAT is why I presented this challenge here! This is certainly an idea I will investigate. Thank you!! :-+
If the security cam has a microphone input, you could even feed this "audio" into it and have everything in one recording.I appreciate what you are saying, but the idea is to have the data displayed on a chart, so that the usage profile can be seen at a glance, hence a data logger is the way to go. However, I suppose having the audio available as well could be useful - but it's on the opposite side of the building and adding this functionality falls under the dreaded umbrella of "feature creep".
Perhaps so, but I am not prepared to try and justify this exercise to your satisfaction because:There is far more detail to the background that is not appropriate to share here, but let me just say that anyone who wishes to criticise the exercise for social reasons is doing so out of ignorance.
At the same time, the same can usually be said of one who attempts to solve a social problem through technological means.
Install a instant hot water electric shower head like this one:Love the wiring! <<shudder>> but, no.
Someone I know did this to monitor his tea drinking,
http://www.ronketti.org.uk/temp.html (http://www.ronketti.org.uk/temp.html)QuoteFor the technically curious, this lot is being processed by a Raspberry Pi, running Raspbian Linux. The Dallas DS18B20 temperature sensors are connected to the GPIO headers (3V3, Gnd and data, which is on GPIO4) and read by the kernel w1_therm module. This then punts the output to a logfile which is read by a bit of Perl that converts the tabular data to a graph, and builds a .png of it before uploading it to the server. It's not perfect. For some reason every now and then the sensor returns a "doesn't respond to CONVERT_TEMP" error and a -ve temperature. This is smoothed out by checking the CRC and re-reading if necessary.
55 replies and these 2 facts weren't included in the OP. :-//Install a instant hot water electric shower head like this one:Love the wiring! <<shudder>> but, no.
1. Situation prevents plumbing alterations. (No, you don't need to know why.)
2. Same for electrical
3. Instantaneous water runs at full electrical tariff, so it will cost far more to run
4. Doesn't address the problem of the shower hog, in fact, it enables them
I will repeat my plea to all - Changing the hot water system is not a solution here!
But you didn't NEED to know about the camera. You were already told that the head of the household had the means to determine the required information. Even I didn't need to know exactly how they were going to do that.
I appreciate what you are saying, but the idea is to have the data displayed on a chart, so that the usage profile can be seen at a glance, hence a data logger is the way to go. However, I suppose having the audio available as well could be useful - but it's on the opposite side of the building and adding this functionality falls under the dreaded umbrella of "feature creep".
Well, knowing about it stops me from suggesting ideas that are not fitting.Only the head of the household needs to know how to identify the parties. That fact alone should have stopped you from "suggesting ideas that are not fitting".
Lack of information makes people fill in the blanks.You need to be a bit more discerning as to which "blanks" are relevant and which are not.
And that still won't tell who used all the hot water, unless you add webcams at the girls college dorm showers. ;DThat is not a problem I have to address. If I simply make the times known, the head of the household can work that out.
I mentioned it because you said that the person was stubborn and difficult. I can just see someone like that saying the "data displayed on a chart" doesn't align with the video footage. They'd say something like, "You faked the dates. The clocks aren't in sync. Your hobby project is flawed, etc." It's a lot harder to deny when its on video with all data right there in one place on a commercial machine.Your point is well taken and, in general, valid. However, while not impossible, in this case I do not feel such a response would be likely. In any case, the additional complexity introduced makes the job more difficult and time consuming.
55 replies and these 2 facts weren't included in the OP. :-//Install a instant hot water electric shower head like this one:Love the wiring! <<shudder>> but, no.
1. Situation prevents plumbing alterations. (No, you don't need to know why.)
2. Same for electrical
3. Instantaneous water runs at full electrical tariff, so it will cost far more to run
4. Doesn't address the problem of the shower hog, in fact, it enables them
I will repeat my plea to all - Changing the hot water system is not a solution here!
You need to be a bit more discerning as to which "blanks" are relevant and which are not.
:-DD55 replies and these 2 facts weren't included in the OP. :-//Install a instant hot water electric shower head like this one:Love the wiring! <<shudder>> but, no.
1. Situation prevents plumbing alterations. (No, you don't need to know why.)
2. Same for electrical
3. Instantaneous water runs at full electrical tariff, so it will cost far more to run
4. Doesn't address the problem of the shower hog, in fact, it enables them
I will repeat my plea to all - Changing the hot water system is not a solution here!
The brief was clear - a monitoring solution. As such, all the behind-the-scenes details, constraints and reasons that had no bearing on providing a monitoring solution were irrelevant.
If you consider the fact that this is an Electronics forum, then asking for help about monitoring here is reasonable. People suggesting changes to the plumbing were reading past the stated objective and inserting their own objectives.
Asking plumbing questions here is a bit off-topic, I would have thought.
Next time I'll just say I need to monitor the flow of water from a hot water system and leave out any other details so people can focus on the declared objective.Insert plumbing flow meter is the cheapest solution and yes, it involves simple plumbing.
Really, so you think we aren't smart enough to offer a wide range of solutions.I was open to a wide range of solutions - to the problem: Monitoring. I doesn't help it if you want to define your own problem and offer solutions for that.
I'll grab my hat and you won't hear from me again.If it's your plumber's hat, then fine, but you will always be welcome if you're wearing your EE hat.
Asking plumbing questions here is a bit off-topicNa,ya just need a bigger soldering iron
Wave guides, where the wave is water are not too far from topic.QuoteAsking plumbing questions here is a bit off-topicNa,ya just need a bigger soldering iron
Might be easier to just monitor humidity in the bathroom. I would think whoever makes the longest RH spikes should be the heaviest hot water user, and you can do that with cheap home weather station type stuff.Nice idea, but some use the exhaust fan - and some don't.
... of an individual who has no Idea that they are the indirect subject of the 'current flow' of discussion.Oh, they know. They are just champions of bullshit - I mean, world class.
Another possibility would be a microphone or vibration sensor to detect if water is flowing in the hot water pipe.
Where is the sensor located?
I've set it up with the sensor simply taped to the hot water line just before the tempering valve.
It's the huge time-constant... bigger than I expected for cool down of a sensor on copper or iron pipe. So I thought maybe on a manifold of the sink? Here we use 1/2" copper pipe and plastic braided supply line to the tap.I will ask you two questions:
Consecutive water use, I don't think you can ID the culprit with such slow data.
Morning showers I imagine it's a lineup, rush and person after person.There is usually a minute or two as people dry off and get decent for the public traverse. It's not as if party B is stripped off ready to jump into the shower as party A reaches to turn the water off.
| Criteria used: 1. No idea what the optimum setup would be, so wasn't fussed about over-thinking an initial configuration - just wanted to get some data to get an idea of the real world 2. Quick and easy 3. Temporary fixture OK for starters 4. Placed on the hot water outlet pipe to gain maximum temperature swing because: a. This would allow easier identification of temperature increases b. This would produce the fastest temperature drops when water flow ceased because of the highest difference between pipe temperature and ambient than other locations 5. Placed as far as possible from the tank, to reduce bulk heating effects from the stored water 6. Sampling rate set at maximum available (every 10 seconds) to get best resolution possible 7. Transmitter placed on tank as high as possible for best Bluetooth range (it has magnets :-+ ) | (https://www.eevblog.com/forum/chat/need-a-simple-temperature-data-logger-any-recommendations/?action=dlattach;attach=1858228;image) |
| Maybe something like this... | (https://www.eevblog.com/forum/chat/need-a-simple-temperature-data-logger-any-recommendations/?action=dlattach;attach=1858255;image) |
Have you considered simulating actual showers of different lengths in order to determine typical usage “signatures”?
Once you have several known patterns of actual usage, you ought to be well equipped to interpret accurately (i.e. accurately enough for your purposes) the real-life usage patterns that get recorded.
What are the chances the tank is undersized for the number of people taking showers?
As has been stated on more than one occasion ... that is not the problem being presented here.
You might want to monitor the ambient temperature. The speed of cooling may be affected by the ambient temperature.It certainly will, but for the current measurement the speed of cooling isn't a big issue - just the fact that cooling can be identified is the important point.
Again, I say, the performance of the hot water system is not the problem being presented here.Yes, they are conducting a surveillance operation against an identifiable but gender unspecified individual who is apparently using too much hot water and eating too much lasagne. So issues about heat capacity, thermal efficiency, shower mixer design and pipe lagging, don't count as this project is just about nailing a pesky perp. Personally, I would just put up a notice telling all gender unspecified users of hot water users to kindly shower 'sans-vapeur' - no steam please as the Stasi are recording your every joule.
Personally, I would just put up a notice telling all gender unspecified users of hot water users to kindly shower 'sans-vapeur' - no steam please as the Stasi are recording your every joule.