WHO USED ALL THE HOT WATER!!! Need a simple temperature data logger ** UPDATE ** - Page 1
Forum section: electronics / general

author: Brumby
author_rank: Unknown
timestamp: August 20, 2023, 02:31:19 am
content: Scenario: "Who used all the hot water?!!!" - typical domestic situation.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.I've looked at various offerings and an off-the-shelf example which appears to have the functionality that will serve the purpose is the Inkbird TH2, which captures the data and allows me to monitor via bluetooth - which is enough.However, I am uncertain as to whether it will operate completely stand-alone. I could possibly tolerate aone-offregistration exercise, but I DO NOT want internet dependence for ongoing function. Not at all, never, ever. It's a completely unnecessary restriction for what I want to do.General reading hasn't made it clear at all.First concern is whether my old Galaxy S5 would be able to run the app, so I downloaded the App and installed it. So far so good. Then I started looking for the T&Cs.I found the set up path through the App really oppressive. It seems you cannot proceed without entering into a subscription for all the "really good extras" (NONE of which are of any interest for this exercise) - even if it is just the 3 day free period. Of course, you can "cancel at any time" - but that's a dance I'm not at all keen about. It also asked for permissions that I really didn't want to give it and weren't necessary for whatIwanted. And then there is the Privacy question.So, I found the T&Cs and came across a couple of details that stopped me in my tracks. Specifically (and I paraphrase):1. You must accept all updates2. We do not guarantee the App will continue to workThat just wreaks of the potential for a problem that I have already encountered in other Apps - where the App is updated to the point where my hardware and O/S are no longer capable of running the App. (Don't anybody suggest I should buy a new phone.)Options:1. Just buy it and see how it goes (price range AUD$20-30 internal vs external sensor)2. Buy it and see if I can write an App of my own3. Build a DIY project. (Is there a design available, with code? I could do it myself, but I don't have enough time to do the things on my list as it is.)4. Suggestions.....

author: floobydust
author_rank: Super Contributor
timestamp: August 20, 2023, 03:24:02 am
content: When I was young, my dad used to use up all the hot water so I would close the valve on the hot water supply until I heard him cuss and swear and leave the shower. Then I had a chance of a warm shower.Once I lived with a roommate that was first in the shower in the morning. He would then fall asleep leaning against the shower wall, until he used up all the hot water... and the cold water then would wake him up. He would fall down and I knew after the big kabang, my turn in the shower next and it was going to be cold. I almost murdered him.I think you need to know the water heating system's status, on/off and log that as well? In Canada we use a hot water tank that is heated by natural gas. So a household always has at least 40L of hot water but once that is used up there is a "recovery time" to heat it up again, that is often a good portion of an hour. You wouldn't know where your system is at only by looking at temperature.Is your water heating gas or electric or solar? The reason I ask is a common problem with a hot water tank is the dip tube (and sacrificial anode) corrodes. So incoming cold water no longer comes in at the bottom, but instead at the top of the water tank where the outlet port is. You end up with a hot water tank that acts like it has low capacity (cold water) at high flow. Also, plumbers don't use galvanic isolators properly causing premature corrosion.Just to make sure your system works, instead of the long Hollywood showers being the problem.

author: vad
author_rank: Frequent Contributor
timestamp: August 20, 2023, 03:41:25 am
content: Tankless water heater is one of the best solutions.

author: IanB
author_rank: Super Contributor
timestamp: August 20, 2023, 03:51:46 am
content: Tape a thermocouple to the pipe and use a data logger?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.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.I guess you will need cooperation of the residents, or they might simply disconnect the logger. But if the residents are cooperative, why not simply ask them who used all the hot water?

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 20, 2023, 04:29:10 am
content: Try the simple solution of partially closing the valve? Then it would take longer to use too much hot water.

author: KE5FX
author_rank: Super Contributor
timestamp: August 20, 2023, 04:47:50 am
content: Or just raise the temperature.

author: Zucca
author_rank: Unknown
timestamp: August 20, 2023, 04:59:04 am
content: Quote from: vad on August 20, 2023, 03:41:25 amUntil the teenager daughter will brake daddy bank causing astronomical gas bills.

author: Brumby
author_rank: Unknown
timestamp: August 20, 2023, 07:38:23 am
content: Additional information prompted by comments...1. The tank is only a couple of years old and there is no indication of any fault - just excess usage. Partially closing the tap at the outlet would reduce flow. While that is an option, it does not address the principle issue.2. I will have NO difficulty fitting anything as the head of the household has raised the request.3. The principal issue is determining how much hot water is being used - and by whom.Identifying the individuals can be worked out from timestamps. Time of day and duration can be easily determined and this will probably be adequate for the basic need. 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.Getting a finer take on actual flow rate would require a bit more finesse. In that respect, the temperature drop over an exposed section of pipe would be useful: A greater drop means a low flow rate, while a lower drop would indicate a high rate. To do this properly I would need two sensors and some calibration experiments ... which could be a phase 2 exercise. Absolute litres per minute is not an objective, so let's not head down any paths that require plumbing.

author: Brumby
author_rank: Unknown
timestamp: August 20, 2023, 07:50:29 am
content: Quote from: IanB on August 20, 2023, 03:51:46 amThis is the basic idea.QuoteI 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.QuoteThis 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.Quote<Answered above>QuoteThey lie

author: tautech
author_rank: Super Contributor
timestamp: August 20, 2023, 07:50:49 am
content: Quote from: Brumby on August 20, 2023, 07:38:23 amDo be aware if your Powerco can control HWC's remotely it may be just not being heated.Better to monitor the power supply to the cylinder too.

author: RoGeorge
author_rank: Super Contributor
timestamp: August 20, 2023, 08:00:15 am
content: 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. And that still won't tellwhoused all the hot water, unless you add webcams at the girls college dorm showers.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: August 20, 2023, 08:58:22 am
content: Day 22 in the Big Brother household and someone has used all of the hot water. Angry housemate Nikki is in the Diary Room... Politics and comedy aside, this scenario suggests you guys have heating system that is not fit for purpose. What are you/they paying for?Google for Bluetooth data logger.

author: Brumby
author_rank: Unknown
timestamp: August 20, 2023, 10:00:17 am
content: Quote from: RoGeorge on August 20, 2023, 08:00:15 amAbsolute 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.QuoteThat is not a problem I have to address. If I simply make the times known, the head of the household can work that out.

author: ejeffrey
author_rank: Super Contributor
timestamp: August 20, 2023, 06:18:48 pm
content: Quote from: Brumby on August 20, 2023, 07:38:23 amI'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. The tap handles set the blend ratio if you open the hot water tap full and then open the cold water tap to set the temperature the hot water flow will decrease.That said it probably doesn't matter. Assuming people are actually in the shower and not just letting the hot water run to make a steam room there is a fairly narrow range of water temperature most people will tolerate so a simple on timer is probably going to be accurate enough.I'm not sure how fast the pipes cool down after the water shuts off and how much that might complicate your measurement. Another possibility would be a microphone or vibration sensor to detect if water is flowing in the hot water pipe.

author: themadhippy
author_rank: Super Contributor
timestamp: August 20, 2023, 06:59:16 pm
content: QuoteQuotesurely you can use the development time to your advantage to get out of other ,less intresting duties."we need to go shopping/visit the inlaws/sort the garden""loved to,but i really want to get this temperature logger finished that you said was urgent"

author: coppice
author_rank: Super Contributor
timestamp: August 20, 2023, 07:10:54 pm
content: Quote from: Zucca on August 20, 2023, 04:59:04 amThe bathroom repair bills after she causes anything not solid plastic, metal or glazed to peel or blacken with mould can exceed the gas bill.

author: Zero999
author_rank: Super Contributor
timestamp: August 20, 2023, 09:15:57 pm
content: Quote from: coppice on August 20, 2023, 07:10:54 pmWhy would that happen with an instant hot water heater but not with a hot water tank?

author: Rick Law
author_rank: Super Contributor
timestamp: August 20, 2023, 10:17:49 pm
content: Quote from: Brumby on August 20, 2023, 02:31:19 amI 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.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. 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.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.

author: coppice
author_rank: Super Contributor
timestamp: August 20, 2023, 10:50:25 pm
content: Quote from: Zero999 on August 20, 2023, 09:15:57 pmEr, 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.

author: ywara
author_rank: Contributor
timestamp: August 20, 2023, 10:56:03 pm
content: I think you need to take a step back and look at the problem statement.The problem statement: There isn't one. Domestic bickering about lack of hot water or energy consumption isn't really a problem of hot water or energy consumption, but a problem of bickering. Bickering is a problem without a solution.So there are two ways to approach this, I think.1. Monitor who is using hot water. I suggest RFID tags attached to all persons. Combined with sensors on the various faucets, shower valves, toilets (if you have hot water plumbed to your toilets), washing machines, etc. you can track who is using what. In many cases you should be able to adapt simple limit switches. In high-flow applications (e.g. a bathtub) you may need an angular position sensor on the blending valve or hot water valve.2. Monitor hot water demand, and correlate with potential culprits. Install cheap wifi cameras in or near bathrooms, kitchens, and laundry rooms. Add simple digital datalogging to your hot water heater(s). When they are on, hot water is being produced since it was recently depleted. You can easily correlate the users to the demand.I suspect #2 is more practical for small households. Perhaps 8 people or less. #1 will scale better to large families into the hundreds.Both of these options probably result in family counseling or court. Tread carefully, but sometimes victory is worth it.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 20, 2023, 10:56:41 pm
content: 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.EDIT: It's a joke!

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 20, 2023, 11:00:33 pm
content: Quote from: Kim Christensen on August 20, 2023, 10:56:41 pmUh 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.

author: tautech
author_rank: Super Contributor
timestamp: August 20, 2023, 11:34:57 pm
content: 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.

author: Someone
author_rank: Super Contributor
timestamp: August 20, 2023, 11:49:54 pm
content: Quote from: ejeffrey on August 20, 2023, 06:18:48 pmWhich 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.Can get a practical shower from 3-5l/m, but some people will remove the restrictors and "enjoy" their 20-30l/min (4-10x difference in consumption/cost/energy/etc).Quote from: Brumby on August 20, 2023, 02:31:19 amThe "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.

author: vad
author_rank: Frequent Contributor
timestamp: August 21, 2023, 12:37:11 am
content: Quote from: coppice on August 20, 2023, 10:50:25 pmExhaust 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.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 12:44:02 am
content: Quote from: Rick Law on August 20, 2023, 10:17:49 pmTaking 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.QuoteOn 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.* Water heaters placed outside is very common here in Sydney for houses. See Dave's video on his heat pump hot water service for a typical placement:** While not ideal, this is not uncommon to see. Snow is not a thing here in Sydney and we don't see freezing temperatures except for the odd occasion first thing in a winter morning, so your average Joe won't even notice.QuoteShower 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.QuoteNot 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.)QuoteThis 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.The 3 system version would monitor (1) the ambient air temperature as well as (2) the water temperature as close to the exit point of the tank as possible and (3) the water temperature further down the "main pipe". The sensors at (2) and (3) would show the temperature drop along the exposed pipe (yes, they would need to have the necessary precision) and this could be calibrated against ambient (1) to derive a flowindication. For a further refinement, a fourth sensor could be set up in some way to give a wind chill factor.At this stage, I have pulled the trigger on a single Inkbird TH2 just as a proof of concept. Anything more elaborate with multiple sensors using something off-the-shelf will hit the hundreds of dollars - and I can't see it being able to process the figures to be useful to an end user, so a custom Raspberry Pi setup or somesuch is a more likely path.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 12:48:50 am
content: Quote from: SiliconWizard on August 20, 2023, 11:00:33 pmIndeed. Not to mention that such a device would cause WWIII and meet with an "accident" in very short order.

author: themadhippy
author_rank: Super Contributor
timestamp: August 21, 2023, 12:56:21 am
content: 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 seconds

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 12:59:00 am
content: Quote from: tautech on August 20, 2023, 11:34:57 pmWhile 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.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 01:01:04 am
content: Quote from: themadhippy on August 21, 2023, 12:56:21 amYeah... nah.That is going to piss off EVERYONE who uses the shower. Revolt guaranteed.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 01:12:43 am
content: Quote from: Someone on August 20, 2023, 11:49:54 pm1. Grey water exit very difficult to access.2. Completely unaffordable in this situationQuoteThat 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.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 01:17:44 am
content: 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.The problem is the same as having bought a cheesecake and cutting it up into 8 pieces so that each person gets 2 pieces - but someone sneaks into the fridge and helps themselves to a couple of extra pieces. Buying a bigger cheesecake is not the answer.

author: Someone
author_rank: Super Contributor
timestamp: August 21, 2023, 02:38:16 am
content: Quote from: Brumby on August 21, 2023, 01:12:43 amStanding 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).

author: Someone
author_rank: Super Contributor
timestamp: August 21, 2023, 02:45:16 am
content: Quote from: Brumby on August 21, 2023, 01:17:44 amAccording to your arbitrary belief of "adequate", as clearly multiple residents believes it is not adequate:a) someone else used too much and there is not enough left for my short showerb) other people are complaining there is no hot water left, but I'm not shortening my showerA very simple mismatch of different people valuing something differently, there is no "correct" amount of water for a household that should be rigidly enforced or legislated. So for their situation it is the definition of inadequate, you wish to pursue a demand management to balance the supply, but it is still inadequate for them as of now.(assuming there is no malicious actor who is simply leaving the hot water running while not using it, purely to deprive others)Seriously, check what the flow of the shower head is. That fixes it harmoniously for the vast majority of cases.

author: floobydust
author_rank: Super Contributor
timestamp: August 21, 2023, 02:59:55 am
content: My next roommate installed water conserving showerheads. Of course I hated the sharp tiny water jets and proceeded to remove the flow control o-ring and drill out the orifice.Ahhh I love Hollywood showers.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.I expect false imprisonment because your datalogs will show a longer cooldown time for the water pipe, long after the shower is stopped.

author: Muttley Snickers
author_rank: Unknown
timestamp: August 21, 2023, 03:02:26 am
content: There is only one thing for it, you need to get evil on their arse.

author: tautech
author_rank: Super Contributor
timestamp: August 21, 2023, 03:10:36 am
content: Quote from: Brumby on August 21, 2023, 12:59:00 amWhat HW capacity currently exists and what is the temp it is set to ?Starting with a higher storage heat effectively lifts capacity by reducing flow rates at point of use.These are simple things anyone can do for a possible easy remedy.Then you can have dictatorial Gubbermints that propose to legislate shower head flow rates to preserve water and power resources and were appropriately booted out at the next elections.Put a 5 minute egg timer in the kitchen then turn ON the taps when 5 minutes is exceeded.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 21, 2023, 03:31:13 am
content: 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: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.But if you don't know the sequence, then how will knowing the times of temperature change help at all?

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 04:15:11 am
content: Quote from: floobydust on August 21, 2023, 02:59:55 amThink about that for a second.The result of frequent observations will give a chart showing the temperature profile over time. From that, you can deduce a few things by simple observation.If I have a chart of temperature every 10 seconds, then I can identify a start time when there is a sharp increase. Likewise, a stop time will be indicated by the beginning of a steady drop. Making observations from experimental exercises will (I hope) soon show how this will appear - and possibly allow for further inferences. For example (assuming we have enough sample points) a fast initial rise will indicate a comparatively high flow rate and a slower initial rise will indicate a lower flow rate.Also, adding extra sensors could identify a variation in steady state flow. For example (for illustration purposes only): If, at a given ambient temperature, the difference between the outlet temperature and a point on the "main pipe" some distance away is 2º then we could infer a flow of one rate. If it was only 1º then the flow rate must be higher. Actual calibration could be done through experiment which might give you a reasonable feel for acomparativeassessment of litres/minute

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 04:33:59 am
content: Quote from: Kim Christensen on August 21, 2023, 03:31:13 amDetermining 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.Quote from: Kim Christensen on August 21, 2023, 03:31:13 amA basic assumption - and very wrong.Using your example, it could be A who is using the bulk of the hot water. B then comes in and uses a reasonable amount, unaware that the tank is now nearly bereft of hot water. C then tries to take a shower and complains when it runs cold. By producing a chart that showed A had the water running for 25 minutes and B only had it running for 6, the culprit would be somewhat more obvious.By adding additional information (as I have outlined in principle) distinction could be made between one person who has the shower blasting like a pressure washer and another that has water falling like a soft summer rain.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 04:38:21 am
content: Quote from: Muttley Snickers on August 21, 2023, 03:02:26 amI think things got close to that yesterday...

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 21, 2023, 05:26:10 am
content: Quote from: Brumby on August 21, 2023, 04:33:59 amSo 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? Good luck with your project, but I doubt it'll provide much useful data beyond what could be gleaned by some intelligent observation.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 21, 2023, 05:30:35 am
content: 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.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.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 06:26:33 am
content: Quote from: Kim Christensen on August 21, 2023, 05:26:10 amThey 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.QuoteSo your criticism comes from the unrealistic expectation that someone is always waiting and watching every day over the whole time someonemightjust 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.

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 07:04:50 am
content: Quote from: Siwastaja on August 21, 2023, 05:30:35 amCertainly pipe temperature isn't ideal - but it is extremely convenient.There is a big difference in duration between washing hands and drawing a bath or taking a shower. That should be easy enough to spot. As for cooling "slowly" - I don't expect that would be too much of a problem. The temperature doesn't need to fall much to identify the fact it is starting to fall. Such a point will identify when the hot water was turned off - which is what is needed. Seeing the temperature continue to fall merely confirms this.Also, the temperature of the water is going to fall as it heads to its destination. How much will depend on several factors, one of which is water flow. The more hot water that flows, the lower that temperature fall will be. This will require a degree of precision that may be challenging, but I have a couple of ideas that may help.Certainly, I would expect that temperature profiles of known events will become familiar and that there will be a reasonable ability to identify unknown events because of this. The unknown is just how distinctive these characteristics may or may not be. However, I'll give it a try and we'll see.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: August 21, 2023, 09:35:41 am
content: What next, a shaft encoder to calculate how much toilet paper is being consumed and by whom?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.This might be an interesting project, but are you involved in someone elses witch hunt?

author: Brumby
author_rank: Unknown
timestamp: August 21, 2023, 11:08:01 am
content: Quote from: AndyBeez on August 21, 2023, 09:35:41 amThat is another sore point in this household. I'll say no more on that.QuoteSo you consider the selfish use of all the hot water for the household and then deny any responsibility for it as an honourable activity?QuoteIt'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.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.

author: AlbertL
author_rank: Regular Contributor
timestamp: August 21, 2023, 12:35:03 pm
content: Here are some water meters with pulse outputs, that you could us together with a temperature sensor to make a BTU meter:https://www.ekmmetering.com/collections/water-meters

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 21, 2023, 02:54:11 pm
content: Quote from: Brumby on August 21, 2023, 06:26:33 amKind 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.So another idea is a vibration sensor attached to the pipe listening for water flow. This will give a faster response than temperature. If the security cam has a microphone input, you could even feed this "audio" into it and have everything in one recording.

author: Zero999
author_rank: Super Contributor
timestamp: August 21, 2023, 05:09:32 pm
content: Quote from: Brumby on August 21, 2023, 01:01:04 amSet 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.

author: KE5FX
author_rank: Super Contributor
timestamp: August 21, 2023, 05:52:19 pm
content: Quote from: Brumby on August 21, 2023, 11:08:01 amAt the same time, the same can usually be said of one who attempts to solve a social problem through technological means.

author: ledtester
author_rank: Super Contributor
timestamp: August 21, 2023, 06:22:48 pm
content: Install a instant hot water electric shower head like this one:

author: mendip_discovery
author_rank: Super Contributor
timestamp: August 21, 2023, 06:46:17 pm
content: Someone I know did this to monitor his tea drinking,http://www.ronketti.org.uk/temp.htmlQuote

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 12:33:23 am
content: Quote from: Kim Christensen on August 21, 2023, 02:54:11 pmBut 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'tneedto know exactly how they were going to do that.QuoteBut, does having this knowledge change the way to approach the problem any differently?QuoteNow THAT is why I presented this challenge here! This is certainly an idea I will investigate.Thank you!!QuoteI 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".

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 12:39:50 am
content: Quote from: KE5FX on August 21, 2023, 05:52:19 pmPerhaps so, but I am not prepared to try and justify this exercise to your satisfaction because:1. I've already said enough2. Privacy considerations3. It would take too long4. You would be unlikely to appreciate the subtleties involved. You know the saying: "You had to be there".5. The usual social tools to address the situation have not been effective. This technological element to the problem is being explored so that those social tools have support.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 12:47:04 am
content: Quote from: ledtester on August 21, 2023, 06:22:48 pmLove the wiring! <<shudder>> but, no.1. Situation prevents plumbing alterations. (No, youdon'tneed to know why.)2. Same for electrical3. Instantaneous water runs at full electrical tariff, so it will cost far more to run4. Doesn't address the problem of the shower hog, in fact, it enables themI will repeat my plea to all - Changing the hot water system is not a solution here!

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 12:52:28 am
content: Quote from: mendip_discovery on August 21, 2023, 06:46:17 pmThank you. It's ideas like this that I was hoping to see.

author: IanB
author_rank: Super Contributor
timestamp: August 22, 2023, 01:31:18 am
content: Depending on your budget, you might consider this?https://www.thermoworks.com/node/It has the advantage that after it has served its purpose, you might find other uses for it (e.g. monitoring fridge/freezer temperatures).

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 01:44:59 am
content: That looks like just the sort of off-the-shelf product that might work. The 30 second minimum sampling time might miss short bursts of temperature change ... but, then, it's the longer ones that are really of interest.The future usefulness is a good consideration. (I hadn't got that far in my thinking yet.)Thanks for this.

author: tautech
author_rank: Super Contributor
timestamp: August 22, 2023, 01:50:05 am
content: Quote from: Brumby on August 22, 2023, 12:47:04 am55 replies and these 2 facts weren't included in the OP.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 22, 2023, 02:52:16 am
content: Quote from: Brumby on August 22, 2023, 12:33:23 amWell, knowing about it stops me from suggesting ideas that are not fitting. You see, I have no idea how large this "household" is... It now sounds more like a rooming house rather than the single family dwelling that I imagined initially. So my assumption, not knowing there was a camera, was that Mom was seeing her 5 kids coming and going from the bathroom to shower for the morning rush. So I thought, "what would be the problem with her also noting how long the water was running?" Lack of information makes people fill in the blanks.QuoteI 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.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 03:22:01 am
content: Quote from: Kim Christensen on August 22, 2023, 02:52:16 amOnly 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".QuoteYou need to be a bit more discerning as to which "blanks" arerelevantand which are not.As stated earlier:Quote from: Brumby on August 20, 2023, 10:00:17 amIn regards to the audio recording:QuoteYour 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.The simple fact of presenting time and duration information is likely to get the desired effect.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 03:38:18 am
content: Quote from: tautech on August 22, 2023, 01:50:05 amThe 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.

author: Kim Christensen
author_rank: Super Contributor
timestamp: August 22, 2023, 03:43:17 am
content: Quote from: Brumby on August 22, 2023, 03:22:01 amI will try and brush up on my mind reading skills. No promises.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 03:50:23 am
content: All good.

author: tautech
author_rank: Super Contributor
timestamp: August 22, 2023, 04:48:52 am
content: Quote from: Brumby on August 22, 2023, 03:38:18 amReally, so you think we aren't smart enough to offer a wide range of solutions.QuoteInsert plumbing flow meter is the cheapest solution and yes, it involves simple plumbing.Even a flow switch like this one can provide what you want:https://www.aliexpress.com/item/32848774229.html?I used a 2" version for pump suction loss sensing in conjunction with a $2 timer to kill the power to a $ $ 3ph pump for dry run protection.There are simple and cheap solutions for all manner of problems some think are hard.I'll grab my hat and you won't hear from me again.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 05:11:56 am
content: Quote from: tautech on August 22, 2023, 04:48:52 amIwasopen 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.QuoteIf it's your plumber's hat, then fine, but you will always be welcome if you're wearing your EE hat.

author: themadhippy
author_rank: Super Contributor
timestamp: August 22, 2023, 02:41:32 pm
content: QuoteNa,ya just need a bigger soldering iron

author: coppice
author_rank: Super Contributor
timestamp: August 22, 2023, 03:39:19 pm
content: Quote from: themadhippy on August 22, 2023, 02:41:32 pmWave guides, where the wave is water are not too far from topic.

author: floobydust
author_rank: Super Contributor
timestamp: August 22, 2023, 05:14:00 pm
content: We have the technology lolNo turbine flow meter or other plumbings mods, an ultrasonic flow meter would be too much.How about using nozzle water exit temp? Even then, quite the lag long 2 minutes for some reason.project athttps://www.hackster.io/85779/shower-temperature-sensor-5e13aa

author: BrokenYugo
author_rank: Super Contributor
timestamp: August 22, 2023, 05:22:41 pm
content: 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.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: August 22, 2023, 05:50:16 pm
content: Love that Arduino shower sensor. Would scare the crap out of the 'technical experts' at the CIA - as it could bare more than a passing resemblance to a detonator connected to a highly sophisticated Chinese circuitboard. Are the bare battery leads almost touching?As this is an electronics forum, I will avoid making any legal arguments over targeted surveillance, data gathering and possible discrimination or harassment of an individual who has no Idea that they are the indirect subject of the 'current flow' of discussion.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 10:55:26 pm
content: That would definitely freak a couple of people...... and it did make me smile.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 10:57:22 pm
content: Quote from: BrokenYugo on August 22, 2023, 05:22:41 pmNice idea, but some use the exhaust fan - and some don't.

author: Brumby
author_rank: Unknown
timestamp: August 22, 2023, 11:11:20 pm
content: Quote from: AndyBeez on August 22, 2023, 05:50:16 pmOh, they know. They are just champions of bullshit - I mean, world class.As for discrimination, it is no more discriminating than someone being called on taking two portions of lasagna wherenhave been prepared fornpeople. As I see it, discrimination is only an issue when the differentiation is based on invalid criteria.Besides, I have a strong feeling that the problematic behaviour might change when the household is informed that hot water usage is being tracked.

author: Brumby
author_rank: Unknown
timestamp: August 23, 2023, 01:39:31 am
content: Quote from: ejeffrey on August 20, 2023, 06:18:48 pmAcknowledgement, apologies and belated thanks toejeffreyfor being the first to present this approach.

author: Brumby
author_rank: Unknown
timestamp: August 23, 2023, 07:44:47 am
content: Well, I had decided to purchase an Inkbird IBS-TH2 with remote sensor a few days ago, as it was cheap and ready-to-go. It arrived today.I've set it up with the sensor simply taped to the hot water line just before the tempering valve.Let's see what I get...

author: Brumby
author_rank: Unknown
timestamp: August 23, 2023, 02:06:57 pm
content: Interesting.....First data (exported from App, dropped into Excel and charted. Chart chopped up for ease of viewing)Labelled points:A. First power up and check. Body heat used for temperature increase.B. (Some time later) Took it outsideC. Attached sensor to pipe. Warm pipe caused increase until reaching equilibrium between sensor and pipeD. First use of hot water - Washing of handsE. Subsequent uses - hand washing I believeF. Filling sink for dishwashingG. Small spike - hot tap turned on for about 2 seconds, if that... etc. etc.No showers or drawing of baths during this period. I am curious to see how they come up.

author: floobydust
author_rank: Super Contributor
timestamp: August 23, 2023, 09:04:31 pm
content: Where is the sensor located? On the hot water supply line of a sink?Scalding guidelines are 49°C (120°F) and others use 60°C (140°F) setpoint to prevent bacteria like Legionella in the tank.

author: IanB
author_rank: Super Contributor
timestamp: August 23, 2023, 09:50:05 pm
content: Quote from: floobydust on August 23, 2023, 09:04:31 pmQuote from: Brumby on August 23, 2023, 07:44:47 am

author: floobydust
author_rank: Super Contributor
timestamp: August 23, 2023, 11:06:05 pm
content: 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.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.

author: Brumby
author_rank: Unknown
timestamp: August 24, 2023, 12:35:47 am
content: Quote from: floobydust on August 23, 2023, 11:06:05 pmI will ask you two questions:1. At what point can you say a particular water usage has begun?2. At what point can you say a particular water usage has ended?QuoteThere 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.

author: Brumby
author_rank: Unknown
timestamp: August 24, 2023, 01:14:55 am
content: Here is a photo of the setup: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 world2. Quick and easy3. Temporary fixture OK for starters4. Placed on the hot water outlet pipe to gain maximum temperature swing because:a. This would allow easier identification of temperature increasesb. This would produce the fastest temperature drops when water flow ceased because of the highest difference between pipe temperature and ambient than other locations5. Placed as far as possible from the tank, to reduce bulk heating effects from the stored water6. Sampling rate set at maximum available (every 10 seconds) to get best resolution possible7. Transmitter placed on tank as high as possible for best Bluetooth range (it has magnets)

author: Brumby
author_rank: Unknown
timestamp: August 24, 2023, 02:22:25 am
content: Other considerations for future refinement:* Place secondary sensor at tank outlet point to see if there is a detectable difference which might indicate flow rate. (Higher difference implies lower flow rate; lower difference implies higher flow rate.) I think it doubtful there is enough resolution to achieve this ... but it might be worth investigating* Fit sensor via a clamp. While being more permanent, this allows investigation of thermal coupling options. Thick metal and/or short length provides greater coupling, resulting in the sensor seeing temperatures that are close to the actual pipe temperature. Thinner metal and/or longer length will reduce that coupling and result in the sensor being more influenced by ambient air temperature.Maybe something like this...In this latter case, while the temperature measured will be slightly less, it will still be notably higher than ambient and a continuing flow of water will maintain this temperature. When flow stops, the lower coupling will result in the ambient air cooling the sensor more quickly, giving a much more visible indication. Since absolute accuracy of temperature measurements is of no real importance here, this is not a problem.* Custom project where:- More accurate sensors could be used and configured for best result in targeted temperature range- Only recording samples of interest - say 5ºC above ambient- Potential for custom software, including computation

author: floobydust
author_rank: Super Contributor
timestamp: August 24, 2023, 03:37:10 am
content: I'll ask you once - what temperature delta constitutes the next person and imprisonment?One time constant looks like about 7 minutes which may lead to mistakes if the heater turns on temp kicks up possibly and your window is only a few degrees.I understand you can figure out shower duration by looking at the derivative of pipe temperature. I think you could get one more piece of info by sensing at the shower mixer outlet instead of the hot supply. I'm not sure why you have a mixer right at the tank.Ideal shower temperature is anywhere between 37°C (98°F) and 40°C (104°F) and no more than 41°C (105°F).Old showerheads were 5.5gpm or 20.8l/min. US national standard of maximum 2.5 gpm flow rate for shower heads was established through the Energy Policy Act (EPAct) of 1992. California is less at 1.8gpm.Could I scam your system by taking a shower with master blaster high flow rate, or high temperature? Your graph would not tell you this.A little math you can check - a 7 minute shower, 50% hot 60°C/15°C rest cold water to get 37.5°C is about 4.73l (10.4l with high flow head) of hot water. But I like it hot, 42°C would use 5.6l (12.5l) of hot water. Not a big difference unless the cold water is much colder.Flow.. well it's the big unknown.

author: Brumby
author_rank: Unknown
timestamp: August 24, 2023, 04:44:19 am
content: This data is from the simplest, quickest and easiest install possible. You have to start somewhere. There's no point building a Cray to see how well your binary adder works. Refinement will follow - if it is required.Even so, this unsophisticated setup has delivered some interesting data.From what I can estimate, thermal inertia is about 30 seconds for the current setup. Differentiating hot water events a minute apart has not been difficult with the data collected so far. Even then, if there are a number of short events close together, then the amount of hot water involved is not significant, so distinguishing each of them is unnecessary. If there is a need to get so particular, then the security footage is timestamped as well and it would be trivial to match traffic and temperature ... albeit a bit time consuming.7 minutes is way, way outside any time constant resolution required. The first 30 seconds after water has stopped flowing is clearly visible and unambiguous. If water starts flowing again within that 30 seconds, then the inertia will still result in a small, but visible dip unless it was only off for a few of seconds. In that case, it is highly likely it is the same person ... and in the case of the (rather unlikely) need for full clarification in such a situation, security camera footage is available.It would be good to get the water flow rate, but it's not clear whether such information is necessary to achieve the desired goal. That goal, by the way, is not to convict, but to initiate a conversation.Please keep in mind the purpose of this exercise is not to track every millilitre of water and every millijoule of energy so you can bill each person for the cost.

author: Dundarave
author_rank: Regular Contributor
timestamp: August 24, 2023, 05:05:58 am
content: 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.

author: Brumby
author_rank: Unknown
timestamp: August 24, 2023, 05:07:34 am
content: Tank heating is done on an off-peak tariff, so the element is switched on at given times, depending on thermostat.One further bit of data from overnight... tank heating. Because the sensor is on the outlet pipe, heat conduction from the tank does affect the temperature it reads. During tank heating, the temperature profile was quite distinctive. The sensor temperature did rise, but much more slowly than when hot water flows and it levelled off at a lower temperature. At the end, the temperature drop was again quite different to flow cessation. The fact of the time of day and the 3 hour duration distinguished this event from any other.

author: Brumby
author_rank: Unknown
timestamp: August 24, 2023, 05:17:36 am
content: Quote from: Dundarave on August 24, 2023, 05:05:58 amAbsolutely!The first step is to see if we can get some data which has sufficient distinguishing features to allow such profiling - which we seem to have.I have already done several "hand washing" exercises to see how they show up. I have also been making notes of when others have done things of note (See the chart above). Today I have noted an honest-to-goodness shower event!Special exercises may come further down the track if there is need for clarification.

author: floobydust
author_rank: Super Contributor
timestamp: August 24, 2023, 08:08:07 pm
content: What are the chances the tank is undersized for the number of people taking showers? How big is it.Looking at US hot water tank manufacturers, their recommendations seem a bit nutbar:For 1 to 2 people: 30-40 gallonsFor 2 to 3 people: 40-50 gallonsFor 3 to 4 people: 50-60 gallonsFor 5+ people: 60-80 gallonsI calc 20 US gal (76L) is 8 minutes with a low flow 2.5gpm shower head.

author: Brumby
author_rank: Unknown
timestamp: August 24, 2023, 11:18:40 pm
content: Quote from: floobydust on August 24, 2023, 08:08:07 pmAs has been stated on more than one occasion ... that is not the problem being presented here.

author: floobydust
author_rank: Super Contributor
timestamp: August 25, 2023, 01:44:40 am
content: To me it looked a little small, that tank diameter...Datalog should be able to see the recovery time, if the system is working well or not.I'm not sure how hard your water is, but here it's common for limescale and calcium buildup to impair heating.Every year or two, we do an acid flush to get the scale out for natural gas heaters, they make a sound like popcorn popping due to local boiling inside.Electric water heaters the element gets scale buildup and it can't transfer the heat, which eventually causes its demise from the heat.

author: Brumby
author_rank: Unknown
timestamp: August 25, 2023, 02:23:00 am
content: Quote from: Brumby on August 24, 2023, 11:18:40 pmAgain, I say, the performance of the hot water system isnotthe problem being presented here.

author: mendip_discovery
author_rank: Super Contributor
timestamp: August 25, 2023, 10:49:10 am
content: You might want to monitor the ambient temperature. The speed of cooling may be affected by the ambient temperature.Can you fit some lagging to the hot water pipe so that you loose as little heat from it when in use.Have fun logging the data.

author: Brumby
author_rank: Unknown
timestamp: August 25, 2023, 12:05:26 pm
content: Quote from: mendip_discovery on August 25, 2023, 10:49:10 amIt 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.

author: AndyBeez
author_rank: Frequent Contributor
timestamp: August 25, 2023, 12:20:48 pm
content: Quote from: Brumby on August 25, 2023, 02:23:00 amYes, 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.

author: Brumby
author_rank: Unknown
timestamp: August 26, 2023, 03:55:19 am
content: Quote from: AndyBeez on August 25, 2023, 12:20:48 pmOh that such a simple action would be effective.This person would ignore such a sign and probably shower longer to spite. If another member of the household called them out, they would deny vehemently even if they'd been in the shower for an hour. The ensuing toe-to-toe would simply escalate as the guilty party would not back down and a third party intervening would have a situation of one word against the other.Do not underestimate the determination and conviction of an entitled bullshitter.

author: Brumby
author_rank: Unknown
timestamp: August 27, 2023, 12:17:03 pm
content: Just as I was looking at some figures, wondering what effect solar heating of the pipework/building might have to the numbers, I received some news.....The party concerned was a guest. One that had abused that hospitality in far more ways than just excessive hot water .... and .... they have vacated, finally.Now I have no need to pursue this any further .... .... but this experiment still has its intrigue.

author: richnormand
author_rank: Unknown
timestamp: August 28, 2023, 07:24:53 pm
content: https://www.lascarelectronics.com/easylog-el-usb-tcat the water heater location.

author: Brumby
author_rank: Unknown
timestamp: August 29, 2023, 02:45:32 am
content: Interesting.That unit has a few more data points than the one I have (32510 vs 30001) and you can select an interval all the way down to 1 second (vs 10 seconds). It can also use other sensors. For my use, not a big deal.On the flip side, it's about 4 times the price. Also, it does not have any wireless communication, so it's a retrieve and plug in exercise which does not suit my application as well as the one I stumbled across. It also doesn't seem to have humidity measurement - but that really isn't of much interest for my use case here.Thanks for the info. It's always nice to see what else is out there.