A tap water heater circuit can be simply built by attaching an iron tube on the mouth of the tap or the faucet, and allow the iron pipe to pass through an induction heater coil. The induction heater will heat up the iron pipe and hence water passing through the the pipe will also heat up and provide a warm water for the user from the other end of the pipe.
Materials Needed
To build this project you will need the following basic materials:
A ready made induction heater circuit that can be powered from a 12V 10 amp SMPS DC power supply.
An appropriately fabricated metal pipe with Bakelite holder at one end which can be clamped to the tap mouth.
An appropriately dimensioned Bakelite box for enclosing the induction heater, the induction coil, and the metal pipe.
The Set Up
The complete set up for the induction tap water heater circuit can be witnessed in the following set up diagram:
In this set up we can see a plated iron pipe or a galvnized iron pipe is clamped to the mouth of the tap via a bakelite adapter cap. The bakelite cap ensures that the heat from the iron is not able to disperse to the tap metal, and remains instact within the iron pipe.
The iron pipe can be seen encircled by the induction heater coil, or in other words the iron pipe is allowed to pass through the induction heater coil.
The metal pipe diameter must be selected to ensure that the amount of water passing through it is not too large, and the water is able to get warm enough while passing through the pipe. The water coming out from the pipe must be at least 35 degrees Celsius warm.
How to Enclose the Whole Set up
The above explained induction tap water heater circuit set up will need an appropriate enclosure which must be light, sturdy, water proof, heat proof, and could be attached to the tap system along with the iron pipe.
An example format of the enclosure can be seen in the following image.
The enclosure should have ample ventilation from the bottom side, so that the parts of the induction heater can dissipate the heat comfortably without getting too warm.
The power to the induction heater circuit enclosed inside must be supplied from an external SMPS unit, which may be rated at 12 V 10 amps.
Using the SMPS unit externally provides the user with an advantage of using the SMPS for some other desired purpose, when the heater is not being used.
Cheaper than Commercial Water Heater
If you compare the above induction based tap water heater circuit with commercially available geysers and water heaters you will find that the above set up is much cheaper and cost effective than the commercial units.
The complete set up can be built in less than $20, which is 50% less compared to the commercial units.
Also, the electricity consumption can be 50% less for the above explained concept, compared to the commercial heater units, which depend on heater coils rather than induction heating system.
Moreover, you get a free SMPS device which you can use for lighting LEDs, driving a power amplifier or a subwoofer amplifier, a benefit you can never get with the commercial heater units.
Dear Swagatam,
I think I have written a couple of times regarding this very type of thing. I haven’t seen a reply to them. I was thinking that using the 60hz house current around a pipe would work. I have bought the 12 v induction heater circuit and used it around a pvc pipe with a stainless steel scrubbie in the pipe. It did heat the water ok. What I would like to know is how many turns of copper wire I should use that would give the same effect with house current or maybe I’m just not understanding how an induction heater works.
Thank you,
John
Dear John, sorry i don’t remember where you discussed regarding the above concept, if possible please provide the article link where you have mentioned about this project.
Presently I do not have a 220 V or 120V directly operated induction heater circuit, all the designs that I have are 12V or 24V rated.
The turns of the work coil will depend on the resonance calculations of the design, the number of turns should match the calculated capacitance value for getting peak resonance, so basically it’s the inductance of the coil that becomes crucial.
Thank you, Swagatam. I guess I did not mention that concept directly when I wrote before. I was trying to figure out in my original post to you what the number of turns of what gauge wire would not burn up when connected the 120v household current. I had thought that if I could build the coil then I could figure out the capacitance value that would work best with that setup. So, I was still in the thinking phase of what is possible (Electricity is very hard for me to wrap my head around.) It is my thought that if I had a coil that would not burn up using house current (I am being safe) and not trip a breaker then I could experiment with the core size. The reason I thought the scrubby would work is because the water will flow through it and because of the fine wire it is made of would be able to heat the water more uniformly. I did, as I said before, get warm/hot water with a coil around a pvc pipe that had a stainless steel scrubby in it using the 12v induction heater circuit. I didn’t feel comfortable using that circuit because the circuit I had bought could only be used intermittently and what I wanted to build would to be able to keep running as long as I wanted (such as heating an in-floor water heating coil). I had also thought that the parts would be simple and inexpensive. I have regular utility power and if I could use electricity that already had a 60 Hz cycle for induction heating, it would be something I could work with. A method like that would not have to generate a lot of heat quickly. I know the higher frequencies are more efficient to get high heat but for me at this point it’s more than I can grasp how to build one.
Hi John, I think the concept that you are referring to may be feasible. We can use an appropriately number of turns over an iron pipe and try passing a high frequency 220 V or 120 V DC through it. Due to eddy current generation the iron pipe then would heat up fulfilling the objective of the experiment.
A similar type of concept can be seen in the following article:
Small Induction Heater for School Project
Thank you for your reply. Isn’t a dc frequency the same as an ac frequency? Anyways, as a general concept, what would the ball park idea be for the gauge of wire and the number of turns required so the coils wouldn’t get too hot. I know there are the small 120 volt ac to 5 volt dc wall warts and they use pretty fine wire. Would that be along the line of the gauge wire and the number of turns that would be needed to be safe? By the way, I always check the box below for an email notice that you have replied but haven’t seen an email yet when a post is made in reply. Am I not doing something right for that notice?
John
DC frequency will not change polarity, but AC frequency will alternately change polarity.
The wire gauge can be an 18 SWG, and the number of turns can be 100 turns minimum, which must wrapped around an iron tube and applied with a frequency of around 2kHz to 10 kHz
The emailing is a automated process done by the website, not sure what may be the problem, I am not an expert in these matters, will need to check it.
Dear Swagatam:
I looked at a wire gauge converter chart of mm to awg and it appears that 16 gauge would be able to carry as much as 10 amps. If I follow what you have in the School Project I could start with 50 turns. Then I could reduce the voltage by adding some resistance in the form of a light bulb or heating element. I could then safely check the results, increase the voltage or number of turns in the wire maybe. I think this is the basic idea that I could use to experiment and by trial and error find something that might work for me. Do you see a problem with this line of thinking?
Thank you,
John
Hello John, the procedure that you have mentioned is absolutely correct, however along with the voltage, it is the frequency that also matters. The frequency actually decides the number of turns that can be used. So along with the voltage you may also have to consider the frequency for fixing the number of turns.
Thank you, Swagatam. I really appreciate your responses and knowledge about this. I will give it a try, experiment with it and let you know how it works.
You are most welcome, John.
Dear Swagatam,
Can I have more details of the induction coil. Where can I purchase it in India. Soecifications of the induction coil etc.
Thanks
Dear Ashok, you can try any 300 watt ZVS induction heater which may be available in any electronic retailer or online stores like amazon, bangood, robu etc.
Iron or other metal makes very little difference. It is largely the electrical conductivity that an induction heater uses.
It has to be iron, otherwise induction heating cannot take place. The core has to be magnetic otherwise induction cannot happen.