Heat circulating fan for my "Cabin in the woods"

[Biker]

Hey folks,
I've been busy with real life a fair bit since hitting the shores of the UK, and one of the things I wanted to do was assemble the parts I bought off eBay for a heat circulating fan for my woodburner. Basically a woodburner heats an entire room, or house if it's big enough, but to have a bit of assistance to swish all that warm air about a bit won't hurt either. So there's a company out there making these Ecofans and flogging them for £55+. The trick is that they're not battery or mains powered, they rely on electrickery.

So that sort of gadgetry is just the carrot on a stick I needed to have a go at making my own... not to mention being a penny-pincher too. (John Fenna taught me so many tips for that, including recycling toilet paper and how he can make underpants last an entire month before needing to be washed! )

Anyway, the parts for this ecofan I bought for around £20 and had them sent to my Mum's address in Kent. I went over to my mates place and while he was busy making some shelf brackets I got busy cobbling the thing together. Happy to say it worked fine. Here's the video of it.

[video=youtube_share;Jzfa885ll8Q]http://youtu.be/Jzfa885ll8Q[/video]

This is going to me mounted on my woodburner once I get back to France. I'll let you know how it works out.

Thanks for viewing.

 

[treadlightly]

Good job Aaron. I've seen these in action and they work well but, like you say, they're too expensive to make them worthwhile for me. Making your own is the solution.

 

[Ogri the trog]

Nice one Biker,

Inspiration indeed

ATB

Ogri the trog

 

[ged]

Great bit of science and, er, engineering Aaron. Do you plan eventually to take any electricity out of something like this? I have a couple of wood burning stoves and I've been kicking ideas around for years, from Stirling engines to thermo-acoustic resonators to liquid metal heat transfer, but I've never managed to work up enough impetus to actually do anything about it.

At the moment I use 240V 23W 6" fans to blow the air around, it works really well. Compared to the ten or fifteen kW that each stove can produce it's negligible, and it's not like the energy is wasted anyway. The fans cost about a fiver each, they have clips and universal joints rather than bases so you can fasten them e.g. on a high shelf or wherever is convenient.

 

[paulnb57]

A build tuorial would be awesome, Ive coveted these for ages, am too tight to pay retail, but would like to make one....

Paul

 

[Mesquite]

Great build Aaron.

Any chance of a list of bits and suppliers you got them from ?

 

[crosslandkelly]

Very neat. Aaron.

 

[ozzy1977]

Great stuff

 

[DaveBromley]

this is ace mate, well done!

Dave

 

[Biker]

Hi Folks,
Thanks for the feedback, much appreciated! I'm rather impressed with it and I am a bit of a gadget freak so this ticks a few boxes for me on that front.

Ged I won't be hooking it up to a bank of batteries or anything like that to scavenge the electrickery, this is just an exercise to see if I could copy something I'd seen online and wanted but that price tag just didn't appeal. Hence the home made version.

Right, some folks asked about the list of bits I bought and sources. Like I said I got most off eBay and other parts were cobbled together from parts lying about in my mate's shed/workshop.

Basically you need two heatsinks. I used computer parts for this and the bigger one at the top, the silver one I bought THIS ONE. The base of it measures the same size as the Peltier device 40mm x 40mm so there's a good surface area in contact with each other.

The Peltier module is exactly the same as THIS ONE. Top tip - the side with the printing on goes to the COLD side of the fan i.e. Upwards. Heat goes in one side and the other side needs to be cooler thus electrcikery is generated.

I saw several fan motors, all appeared to be the same spec but the prices were a LOT different, I opted to buy THIS ONE. When I assembled mine I found out I'd got the blade sucking instead of blowing so I simply swapped the wires over. As standard this motor spins in a clockwise direction as you look at it with the shaft facing you. Just thought I'd mention that.

All the sellers were from the UK as I wanted them delivered sooner than later had I ordered them from China Spring might arrive before they did.

Fitting the motor to the heat sink just took a bit of head scratching and I ended up setting it into a large polo mint shaped block of heat resistant plastic my mate had kicking about in his shed. I had considered using a big jubilee clip and clamping that around it with a bracket jammed between the cooling fins. Literally whatever works should be fine. I just wanted something a little more aesthetically pleasing. I'm still not totally pleased with the finish so I may well tweak it once I get it back home to my workshop.

The hub for the propeller was from a plastic gear cog with a 2mm hole that fitted over the shaft of the motor. The propeller wasn't actually a baked bean can but a piece of 25mm angled alluminium. I heated it up annealing it to make it soft then hammered it flat and made the prop out of that. I just centre popped the ally right by the hole where the cog came through to clamp it in position, it seems good and solid.

The bottom heatsink was something I acquired out of a box of bits in my brother's shed, but a simple lump or iron or aluminium should work fine, just needs something to absorb the heat.
I also had a tube of thermal grease, which I will spread a dollop onto the surfaces of the Peltier module for a better thermal connection between the surfaces.

Once you have the two heatsinks and the peltier module between you clamp them together, just don't crush it. Mine is help by a piece of copper wire at the moment.

Hope this "tutorial" helps. Any detailed question just ask and I'll try to help answer them.

Happy new year for tomorrow.

Biker

.

 

[rickyamos]

This also might be of interest for others wanting to heat a small space for free:-

http://lifehacker.com/5574597/build-your-own-soda-can-solar-heater

just a thought

 

[John Fenna]

Biker...
That looks great and I only have one question for you...
You said you made it at a "Mates" place....
I was unaware that you had any mates!
Who was it really?

 

[Mesquite]

Biker...
That looks great and I only have one question for you...
You said you made it at a "Mates" place....
I was unaware that you had any mates!
Who was it really?

Obviously less than you judging on how many of us sent you Christmas presents

 

[Biker]

Biker...
That looks great and I only have one question for you...
You said you made it at a "Mates" place....
I was unaware that you had any mates!
Who was it really?

Go to mates-for-hire.com I use it regularly. The monthly installments aren't too bad, but obviously you get what you pay for. The bargain basement section matched me up with some stumpy hairy Welsh git with a fetish for pink merchandise. I rejected him of course. But if you're willing to spend more than 25p a month the choice does get better.

 

[John Fenna]

Go to mates-for-hire.com I use it regularly. The monthly installments aren't too bad, but obviously you get what you pay for. The bargain basement section matched me up with some stumpy hairy Welsh git with a fetish for pink merchandise. I rejected him of course. But if you're willing to spend more than 25p a month the choice does get better.

Great link - I may use them some time!

 

[Biker]

Just in case you're interested back in January of this year (2014) I made another one of these woodburner fans and traded it with someone for their old bench mounted mortiser machine. Bit of a bargain I thought! But a trade is no robbery and we were both happy.

Obviously this was in a cold workshop in January so here's me sporting a rather fetching beanie hat.

Just for your info I made that first fan for my woodburner in my Cabin in the woods (with WIFI). However, the woodburner is so bloody efficient I don't need the fan at all! But it was a fun project and I enjoyed doing it.

Here's the video of the MKII fan.

[video=youtube;jrCm0Q9ADos]https://www.youtube.com/watch?v=jrCm0Q9ADos[/video]