Internet of Things: Shower Control




Reduce hot water consumption by 40% and still have a good shower.

For many years, I was wondering, how I to reduce the shower time of my children. nowadays, they have the age of 14, 16 and 18. They like to shower for, at least, 5-10 min . 8 min is the average shower time. Which costs 500 € annual.

The aim of this Shower Control experiment is: Saving 200 € annual and still have a comfortable shower.

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Step 1: ​The Approach of the Shower Control

A simple solution, which is used at some camping, is simply stopping the hot water supply, after 5 min. This is not a user-friendly approach, the uncertainty of the switching off moment gives a unpleaseant experience. Still, it is crucial to reduce the water supply, after a certain time.

So, I started to implement the following approach:

  • Full flow of hot water for 3 min
  • After 3 min, a short "notification" reduction of hot water for 3 s. Which feels comfortable and is clearly noticed.
  • After 4 min, again short "notification" reduction of hot water for 3 s.
  • After 5 min, reduction of hot water by 70%. With this reduction, it is still possible, to finish the shower. However, it is not comfortable anymore, promoting to stop quickly.

Step 2: The User Interfaces

The best user interface, is no user interface (The Best Interface Is No Interface: The simple path to brilliant technology, Golden Krishna)

So, the basic interface, is simply the standard knob of the shower. No other, buttons or steps are needed. Simply switch the shower on. The "notification" water reductions, give the progress feedback to the user.

To promote, the reduction of the shower time, I introduced an extra feedback. After the shower, the amount of hot water used, is translated into the colour of a Hue Go. The Hue Go is located at the countertop near the breakfast table. So, the family, can see of each member, the "shower" performance.

The following simple colour scheme is used (see details in SW):

  • Smaller than 3 min - Green
  • Smaller than 4 min - Yellow
  • Larger than 4 min - Red

Step 3: The HW

The standard platforms used are:

Specific parts are:

  • Embedded SW to read flowsensor, control solenoid valve, handle timing and data (see next step)
  • Flowsensor, solenoid valve and pipework, installed in the hot water line of the shower

The valve, flowsensor needs to be connected in the hot water line of the shower.

Step 4: The SW

Via the Arduino IDE, configure the system:

- Temboo account (see Temboo-Google ~Docs)

- Google Docs

- IP of Hue bridge

- ID of lamp to be controlled

PS. the SW is robust and runs now for weeks without flaws. However, for sure not optimised with resect to resource usage.

Step 5: Bring It Together and Start Testing

Start with testing the system, without the Temboo and Hue part.

When a flow is detected, the counter starts running and the solenoid vale will be controlled to reduce the flow at the required moments.

When the flow has stopped, for longer than 90 s, the system will be resetted and the data will be stored.

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    18 Discussions


    2 years ago

    Good idea!


    4 years ago

    Awesome project. I'm so glad I don't live at Olaf's house. ;)


    4 years ago

    I like the idea. You could even limit the upper temperature, to make the shower safe for kids, and better for your skin. Nice!

    1 reply

    Reply 4 years ago on Introduction

    Indeed, this can be easily implemented. I did not show on the schematics, but there is already a temp sensor attached to the water line. At this moment, it is just to monitor the hot water temp. The data is stored in the Google documents, which is very convenient.


    4 years ago on Introduction

    maybe you might want to just get one of these...? I've used one and they are great.

    1 reply

    Reply 4 years ago on Introduction

    Good hint. Is more or less the same function, than in standard product. Thanks


    4 years ago

    Great idea! Where did you purchase the solenoid and flow sensor?

    1 reply

    Reply 4 years ago on Introduction

    Hi, both I bould at RS. The flowsensor (V8189- flow range 1.5 - 30 l/min) is about $40. The valve about $60.


    Reply 4 years ago on Introduction

    Hi, we live in THe Netherlands, it's the hot water (Gas) what is expensive. And actual, it is the tax we have to pay, which make it this expensive.


    4 years ago on Introduction

    This is a brilliant idea, nicely done! My kids have started taking ridiculously long showers and using up all the hot water, so this would be an ideal item to have at my house. Thanks for sharing this!