Introduction: Portable Shower Water Heater

This project came to me while trying to figure out how to reduce the electricity bill and eventually I came up with an idea. What if we put heating elements inside or rather on the showerhead itself and just have single power supply unit?

*This is not entirely a conceptual design since I did testings on smaller scales of the idea and it works, I couldn't make the entire model purely because of time and resource constrains.

Step 1: Heating Elements of the New Design

The design has tiny heating elements which are placed right on the openings where water exits so that we are heating up a very small portion of water at a time.

Coils are made from 5 wraps of 28 gauge Kanthal A1 wires, the inner diameter depends on the openings on your showerhead, it's best if the size is the same as the opening.

Be careful of the type of the material your are using and research them if you're not going with kanthal, for example titanium wire reacts violently to rapid changes in temperature and will EXPLODE!

The higher number of coils on the showerhead the higher power it needs so be mindful of that.


My conceptual design has 16 coils and the rest of the openings are closed and by calculation it uses roughly 450w in total, 28 watts for each coil according to my calculations and testings.

The tempreture of water was around 26°C before testing and immidiatly after powering the coil I got the tempreture of 36

Step 2: How to Wrap the Coils So Tiny?

I used a needle that was the same size as the opening, using a paper clip would do as well if it's the proper size.

Step 3: Coil Isolation

Coils need be isolated and by that I mean we have apply silicon past or maybe cook the coils inside a silicon cover, that allows the heat to be focused toward the center and we won't have leaks from the side.

A proper cover or isolation helps keep the heat from spreading to the showerhead.

Step 4: How to Bind the Leads

Soldering is an option but soldering Kanthal isn't an easy task so binding them is the better option and for that we need some sort of a clamp so that it can hold the heads of he coils and let us connect them to a power supply in parallel.

Tiny screws and nuts are definitely an option to do this but if you find something better please let me know. If you have a 3D printer then you can print and design an entirely new showerhead with small screw holes.

Step 5: Power Supply

A normal computer power supply would work, the higher the wattage the hotter it will get obviously but I'd suggest using a thermostat for one of the coils just in case.

Step 6: My Testing Sample

It doesn't look nice but it proved to me that it works, I used epoxy to cover up enough openings to keep the head from exploding due to pressure build-up. After 2-3 testing I had to remake a new one with the exact same specifications.

For powering the coil I used a portable wattage regulator unit (RX-200).

*The samples got destroyed often because I didn't use proper materials like silicon so the coil melted through the plastic.

Step 7: Finally...

It's safe to say after all that, it's not something that anyone can build by themselves. I struggled through a bit because I didn't have the time,funds and tools required to make a full prototype.

It require more research and testing to reach it's full potential and after doing the calculation it shows promise that it is doable. Please leave me your feedback, I'm always looking for constructive feedback to help me get better.

My thesis on this is around 40-50 pages long but I kept it short and hopefully comprehensive here but do not hesitate if you need more info and ask me.