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
July 17th, 2007 at 7:01 pm
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.
July 18th, 2007 at 10:09 am
[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.
August 27th, 2007 at 8:29 am
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.
October 28th, 2007 at 4:36 pm
Some information on semiconductors that could be used for this purpose,please
January 12th, 2008 at 9:31 am
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 (www.caframo.com) want me to buy another fan at £100 sterling? thanks
January 23rd, 2008 at 5:43 pm
use a peltier cpu cooler.. its probly what you have now.
February 16th, 2008 at 12:23 am
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.