The Seebeck Effect

heat fan

Why not get more work out of your wood stove? this device uses the Seebeck Effect to run a fan that will move air from your stove to other parts of your room. Its a clever idea alright, it’s pretty much the same thing that powers space craft except your not using burning wood as your heat source – your using the natural decay of nuclear materials.
As I encourage everyone to play with science whenever possible, I’ll tell you how you can make your own Seebeck Effect electrical generator.
You’ll need the following:

      A steel nail – 4″ long will do
      Some copper wire – stranded about the diameter of a coat hanger
      A candle – nice sized on a sturdy base
      A volt meter of some sort – you could use a small motor if you wanted but you might not see any movement on your first try
      Something to hold the nail with, it’s going to get hot.

Strip the insulator from the copper wire and wrap some around the nail.
Around a four inch nail I’d wrap about six inches of wire in a space of apx. one inch.
Connect the leads of the meter to the nail and the wire and hold the wrapped part of the nail in the flame of the candle.
You should see a small voltage show up on your meter. Pretty cool, eh?

Yes, you can build bigger ones out of better materials but at some point you end up melting your experiment. I suppose if you had some good thermocouples (that’s what the bi metal junctions are called) and some very low voltage LEDs you could build a sundial that you could read from inside your house. Leave a comment if I lost you anywhere.
Anyway, the bi-metal strips in the little fan are doing the same thing as the wire and nail, just that they are built of metals that have a better energy coefficient. A pretty good use of science if you ask me.

Ecofan Woodstove Fan

science, thermal, clever, neat

13 thoughts on “The Seebeck Effect”

  1. A picture of a fan is posted, yet your instructions tell the reader to use a nail and some wire? And there is no instructions on how to build the fan. Huh? Certain metals have a better energy coefficient? Huh? Doesn’t sound like science to me.

  2. [iamdum]Now see, if you had read the entire article you would have noticed that I’m telling people how to make current flow from dissimilar metals via heating, not how to make a fan. The link to the fan in the photo is at the bottom of the article. I bet that with a trifle amount of work you could figure out how to power a fan from a nail and some wire.
    As for the different metals having better energy coefficients, that just means that junctions of some metals will produce more current flow than others.
    Look it up if you don’t think that it’s science.

  3. Sure it’s science. But I’d like to do a further step, like to use natural semiconductors to enhance the efficiency, as in peltier elements.
    Anyway, very nice experiment.

  4. Some information on semiconductors that could be used for this purpose,please

  5. I have a CAFRAMO stove fan that uses your principal – the fan no longer works – any idea where I could purchase the semiconductor device to repair it – Caframo ( want me to buy another fan at £100 sterling? thanks

  6. I have just installrd a large solar hot water array, I’m looking to use the excess heat during the summer months in a productive way. I’v looked at adsorption chillers (keep the house cool, but way to expenxive to even think about playing with). I’v looked at sterling engine, (my system not hot enough), and now I’m toying with the idea of Peltier junctions to create power,(i’m not sure this sounds cost effective) I just picked up a few Peltiers and looking forward to playing with them. Does any one have any good ideas for using this excess heat in the summer? It will produce much more than I need for domestic HotWater.
    water @ 220f and air around 70f in summer.

  7. What kind of voltage ,current, and watts could be obtained in stainless steal pot full of stainless steal washer with aluminum washer where a copper wire is in contact with the pot and another copper wire is in contact with the aluminum washer that are in either the top or bottom of the pot.

    I would like to charge a twelve volt battery system using a fresnel len array to focus heat on the pots to creat h2 gas to burn in a electric generator for charging the batteries enough to power a twelve volt appliance house. this method avoids obsolesences of PV cell panels which need rewiring. Maintainance is just stiring the washers and a light hydrogen peroxide bath for the washers for decades on end for perhaps iwo centuries.

    Could anyone give the details of how to adjust such Seebeck effect devices? These devices were used in the 1919 period at that time called a thermopile minus the h2 gas and electric generator.At that time they were heated by natural gas flame.

  8. [J. Scherer]: I think your pot-o-washers would short themselves out unless you isolates them from each other. To answer your question though, I can’t. I’m not sure what equations you would need to solve your problem. I would suggest you build a steel washer + aluminum washer ‘pile’. Attach volt meter leads to it and then heat the pile with a Fresnel lens. Use this data to figure out how many you will need to charge your batteries (or crack the H2 out of water, your choice). I’d love to hear your results!
    Best of luck,

  9. Would an steel wire mesh allowing the aluminum washer to be in contact with the steel washers yet seperate be what your suggesting for the thermopile design I would like to try building some day?

  10. A copper sheet can be dented to hold a few layers of copper washer and afew layers of steel washer that totally shade the copper sheet. This apparatus could then be low focus heated by sun light using an fresnel lens horrizontal above the horizontal copper sheet that has a pile of steel washers on it. This should be an easily built thermopile(seebeck effect device) if a copper wire is attached to the surface layer of steel washers and to the copper sheet.

    why the washer? Maintance the becomes washing every thing in hydrogen perioxide when oxidation occurs and putting it back together.

    It should be easy to get parts for centuries.

    I want to generate H2 gas and burn it in a generator to charge or run a 12 volt appliace house some day.

    Is this description likely to work without eating up the copper sheet?

  11. Sorry Correction



    A crude thermopile generates electricity by heating two metals like copper and iron in contact (not bonded) together and in the past a huge one was built with considerable current and workable voltage and watts using natural gas for heat which a solar reflector concentrator made of copper sheet could replace.

    A very small refinery and foundry could make copper and iron pellets(or washers) from Moon dust (or from Earth Sand separated by magnet deflection when poured) separated by a copper wire hole filled grill allowing contact but separation between the two different metal pellets types in a concrete Can where both ends have sunlight reflected onto the Can ends in a shaded area so that proper heat difference makes the thermopile work.. Just plug wire into Each end of the concrete Can laying on it’s side into the metal pellets to get electricity.the Can ends are a metal sheet of copper for the copper pellet side and an iron sheet for the iron pellet side.the Pellets hopefully take most of the oxidation over time so maintance is stiring the pellets or cleaning them with 3% hydrogen perioxide solution. It works on the Seebeck Effect.

    Moon dust is pre-mined ore laying everywhere bathed in sunlight energy to be tapped with thermopile electricity to be refined for Rare Earth Metals of extremely great Earth value make a Lunar Earth Economy to fund Mars missions for water at first for the Moon.

    When Photo Voltaics Panels which break down occasionally from heat stress can be made on the Moon in the future, all that copper and iron pebbles are available to make things out of or shipped to Mars as crude thermopiles later since the further distance Mars needs the ultra reliability of thermopiles since Earth Supplies of Solar cells (PV) would take too long at this point to arrive to prevent death.

    I wish I had the details, but my unusual memory only remembers what a thermopile is and that large ones have been made at sometimes about in I think the 1919 or later.

    Such a thermopile on the Moon without fast oxidation would last centuries without maintainance.

    It took a while ,but my memory kicked in.
    Jeffrey Scherer

Comments are closed.