So I bought an EcoFan for a friend and decided that it was a cool concept and built one from scratch. The fan gets its power from a peltier element that is used in reverse, i.e. it is generating electricity from the heat given off from the stove top.

This peltier cooler is used in cooling cpus to tabletop wine coolers. Usually electricity is used to generate the peltier effect and causes one side to cool while the other side heats up. More can be found on the wikipedia article on http://en.wikipedia.org/wiki/Thermoelectric_cooling

I always wanted to build a Stirling engine but the complexity was a little too much for me, but this project was easily doable as a weekend project!

Tools required:
C-clamps (or vice grips)
Soldering Iron

Materials required:
1x 120cm CPU Heatsink ($20 shipped internet)
1x Peltier ($30 shipped ebay)
1x 1.5V Radio Shack hobby motor ($3)
1x Pentium II heatsink (salvaged)
1x 6" propeller (from my RC planes)
1x scrap 1/8" aluminium plate
6x nuts and bolts

It's relatively easy to build. I just sourced the cheapest and largest heatsink on the internet, which came to this 120cm massive heatsink for $20 shipped. It included all the right mounting plates that just worked. It had a mounting plate that was wide, came with a whole bunch of screws to mount it too. WIthout this it would have made it a whole lot harder to mount.

The $30 thermoelectric generator was sourced from ebay through a local vendor (because I was impatient and wanted to build it by the weekend). I also bought the high temp version, which raised the price considerably (which I have found isn't quite necessary as the module never gets that hot enough). So, if you're more patient, these can be sourced through ebay from chinese vendors for under $15.

The electric generated from the module is roughly about 1.5-3v. Not a whole lot of power, so Radio Shack to the rescue! Got a hobby motor for $3. And using a salvaged propeller from one of my rc aeroplanes, I managed to push fit it into the Radio Shack motor.

The base plate is a 1/8" aluminium plate I found and I used a hacksaw to cut out the pieces, then file away the edges.

There's no plans for it because it's basically lining up the holes, clamp it down, drill the holes out (although it helped that I had a Bridgeport mill, I could have just easily used a hand drill). Also I wanted to make it in such a way you can have a margin of error. I suppose you could also tap the holes and bolt it right on, but I wanted to keep it simple to build.

I made a little base and riser for the motor so it sits more centrally on the top heatsink and just ziptied it up.

The fan base heatsink is a Pentium II heatsink that I had laying around. The heatsink also does two things, one is that it raises up the height, and second is to reduce the temperature getting to the peltier module (because I wasn't sure how well it could dissipate the heat)

After the first run, I could touch the top of the heatsink and only felt that it was slightly warm. This fan works better than the EcoFan in the fact that it dissipates the heat better and can be put up front on the stove without losing too much efficiency.

All in all, about a couple hours of work!

So have fun building your own!
<p>I have tried to build this , but as the stove gets hot it heats up my <br>cool side heatsink (dell) too ,thus there is no temp difference and I am<br> getting ca 1.2V max . I have used a small hobby motor which won't <br>operate at this voltage. The fan works perfectly if I place it on a <br>burner , where heat in more centered under the fan . But when placed on <br>the stove I guess I am losing the temp difference. Any recommendations <br>on this please?</p>
I built one of these with two Perrier heat systems and they no longer work. I think I keep burning them out. Here are pictures. What am I doing wrong?
<p>I would suspect that if you were drawing more air through the plates of the heat sink, you'd be cooling that side of your Peltier more quickly, thus reducing the chances of damaging your Peltier. Repositioning the fan so that it cools more of the fins, or putting a shroud around it so that it draws primarily through the spaces between the fins may help.</p>
<p>Pretty cool well done, I bet it gets lots of looks? Might give it a go one week end cheers.Steve.</p>
<p>Stoves get quite hot, but most TEG/Peltier plates cannot take the high temperature. To buy one that uses high temperature solder etc so that it can take 250degC costs several tens of $. Ebay has Chinese ones claiming to take 150degC, but I have heard this is a lie, and that they break. Which ones are you using?</p><p>You might get away with only a lower temperature capable Peltier plate because you are standing it off the stove surface using the smaller Pentium heatsink; this is reducing the temperature on the hot side of the Peltier, but it also makes everything less efficient.</p>
This was a great little project but it wants a bigger fan blade. I also blew up the first module as it got too hot. So there are three screws underneath as stand offs.
Hello, I'm trying to make one myself, however the height can't be over 10 cm. What I use as cold side is one cpu-heatsink, the warm side is one &quot;Aluminum Alloy Heat Sink For Solid State Relay SSR Heat Dissipation&quot;. With one tec1 pelltier element. My question is why it doesn't run a 12v fan?
<p>Simply because you can't get that much power (voltage) out of the module unless you have a lot of TEC/TEG modules wired in series.</p>
Hi,<br>I have read your input on my problems. Would it work if I do as he does, use a ac electric motor? If it does, do you know where I can find a propeller that can fit in a space with over all height of 10 cm? ....with suitble material for wood stowes?<br>Thanks for the help.
<p>What you have to do is to get a faster spinning motor with a smaller propeller + you will have to live with a little noise from the device because of it's speed. The speed will make up for some of the downsides of a smaller propeller when it comes to the amount of air moved.<br><br>I have a similar problem if I were to build one, but I would have bought two small motors, two propellers and two TEG modules.</p><p>Examples:</p><p><a href="http://www.ebay.com/itm/201229071773?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649" rel="nofollow">http://www.ebay.com/itm/201229071773?ssPageName=ST...</a><br><a href="http://www.ebay.com/itm/391100073661?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649" rel="nofollow">http://www.ebay.com/itm/391100073661?ssPageName=ST...<br></a><a href="http://www.ebay.com/itm/131668463520?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649" rel="nofollow">http://www.ebay.com/itm/131668463520?ssPageName=ST...</a></p><p>That is what I would have tried for my first attempt, but there are probably better options.</p>
<p>&quot;1x 120cm CPU Heatsink ($20 shipped internet)&quot;</p><p>Well - THAT is one huge heatsink :-D</p>
<p>ok so it doesn't matter if I buy a &quot;cooling&quot; or Heating&quot; Pelletier because a heating one is just a cooling one turned upside down? IF correct, how do I know which side is the side that faces the stove? also, are they all the same voltage regardless of their size? (20, 30 40MM) ?? thanks!</p>
<p>Zacker , it only depends on the polarity of the module. One polarity will heat up and the other one cool down. </p>
<p>Cool, thanks. So it doesn't matter which side faces up or down as long as I get the wires onto the correct terminals of the motor.. good.</p><p> I got everything I need now except the module, im STILL waiting for it to get to me. lol. I bought the 40mm module. </p><p>What works better, using a heat sink for a base as you did or a solid block of 1.5&quot; x 1.5&quot; Aluminum? Thanks again! </p>
<p>This would be perfect for an ice fishing shack stove.</p>
<p>I have just bought an ecofan 812. They say the fan deteriorates in 2 years.</p><p>I am getting the impression the fan should be mounted on the top of the unit so it's internals will not melt over time.</p><p>DIY'ers does my thinking make sense? Or is something else in play here?</p>
<p>Nice job.<br>No mention of the finned Alloy and Copper tube arrangement though, where was that sourced?</p>
<p>I read it was a computer fan.</p>
<p>How are you securing the Peltier to the heat sink and the CPU heat sink? Is it being clamped together with the assembly or did you souder or glue it into place?</p>
<p>I have a question on your Peltier Elements. What wattage is it. And size in Millimetres. I know there are various sizes and wattages...And for this project would make a big difference.</p><p>73's de WL7JA</p>
<p>cant one use two or three pelletiers wired in series to get more power to a bigger motor? or does it really not matter how much air is displaced? </p>
I like this. But everything here can be had for free from an old scrap computer except the peltier. I happen to have one of those in a crappy $20 12v drink cooler that leaks. Most computers have 2 heat sinks, already have the fans w/motors, and plenty of aluminum or sheet metal scrap.
As he sed, peltiers in generate mode only put out a couple of volts. not all computer cpu fans will spin at that level..
It has a steampunk feel to it. Nice.
I really like this and would love to build one (or three) for my stoves because I tend to find the heat being trapped in the inglenook fireplace. <br> <br>Where did you get the peltier module from? What's it's spec? And is it worthwhile buying a high-temperature one? <br> <br>Thanks
This looks really cool. I'm not totally sure what it is for though. I have never heard of a stove fan before, is it to blow hot air around? Either way I want one hahaha

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