The fan gives you coolness on a hot summer day.  The heater inside provides you with a warm breeze in those cold winter months. This fan/heater comes with a ambient led indicator:  cold=blue, warm=purple. The fan speed and the amount of warmth can be fine-tuned.
As an extra it is suitable for extracting harmful solder fumes. Replace those bulky desk fans with this smaller more convenient fan.

The total cost of the desk fan/heater =  7 dollar. The only part I bought was the PWM dimmer, all the other parts were laying around in my garage.

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Step 1: Materials and tools

Picture of Materials and tools


  • Power Jack
  • Spring
  • Turning knob
  • Wooden board 9mm thick
  • Wooden stick 12mm in diameter
  • Switch
  • Computer fan 12v
  • PWM dimmer
  • RGB led strip
  • Power supply 12v 3amps minimum
  • Electric wires
  • Copper rods 10cm long 1,5mm thick


  • Super glue
  • Wood glue
  • Wood wax
  • Jig saw
  • Sand paper
  • Wood clamps
  • Drill
  • Drill bit  5mm, 6mm, 7mm, 12mm
  • Hole saw 90mm
  • Solder
  • Solder iron

Step 2: Sawing

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The final product will be a cube. The wood I used is 9mm thick so every measurement is made keeping the thickness of the wood in mind.

Saw 2 squares of 12x12cm, 3 squares of 10,2x10,2cm and 2 rectangles of 10,2x12cm, 4 little rectangles of 1x1,5 cm.

Saw 2 pieces of 3cm from a wooden stick (12mm in diameter).

Step 3: Drilling

Picture of Drilling

I made a drawing of the ventilation holes in Sketch Up, which you can download below. Glue these drawings on the two 12x12cm pieces and drill the circles out using a 12mm drill bit.

Drill a  hole (7mm in diameter) 2,5 cm from the side of one 10,2x10,2cm piece

Drill two 7mm holes 2,5cm from the side of another 10,2x10,2cm piece, leaving at least 2,5 cm of space between these two holes.

Drill a 9cm hole in the middle of the last 10,2x10,2cm piece and drill a 5mm hole on the side (for putting through a cable).

Drill a 5mm hole in the middle of each 1x1,5 cm piece.

Drill two 12mm holes on the  long side of a 10,2x12cm piece 1,2 cm from the side and 7cm from each other.

Step 4: Gluing

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Glue two 10,2x10,2cm pieces (square angled) to one 10,2x12cm piece.

Glue the 10,2x10,2cm piece with the 9cm hole in the middle between the two other 10,2x10,2cm pieces approximately 3cm from one side.

Glue the last 10,2x12cm piece on top of the 10,2x10,2cm pieces.

Glue the two 3cm pieces into the 12cm holes of the 10,2x12cm piece.

Step 5: Heating

Picture of Heating

The heating is done by a spring stretched between two copper rods.

Don’t just use any spring but measure the amperage first by applying a heavy 12v source and a multimeter.  My spring drew about 2,5 amps so it will produce about 30watt of heat at 12v . Well 30watt is not a lot, it will not heat up a room. But it will give me a warm stream of air on me while working on my desk.

Solder the spring between  two 10cm copper rods.

Put the four 1x1,5cm wooden pieces on each end of the rods. Glue these pieces in the corners of the so far wooden box in front of 10,2x10,2cm piece with the 9cm hole.

Solder a cable on each copper rod.

Glue one 12x12cm piece in front of the box for the spring.

Step 6: Electronics

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circuit desk fan.png

Solder cables on the positive, blue and red of the RGB led strip and glue it in front of the 1x1,5 pieces. Put the wires through the 5mm hole.

Glue the fan in to the box. Watch the direction of flow indicated on the fan.

Glue the power jack, the switch and the PWM dimmer in place.

Follow the schematics in the picture to connect everything together

If you do this correct the blue led and the fan will start to work while you turn the potentiometer of the dimmer. When you push the switch the red led turns on (together with blue it will be purple), and the spring will become warm. Caution: the spring should never be under tension without the fan turning, otherwise the spring becomes too hot and will burn down.

Glue the last 12x12cm piece on the remaining side.

Step 7: Finishing touch

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Gently sand the whole cube.

As finishing you can apply wood wax.   

Step 8: Enjoy

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Well, that’s it. After the hard work making this you can relax and enjoy the gentle breeze of your just made desk fan.

parkmana25 days ago

Those 12v car lighter have a heating core made of NiChrome (Nickel/Chromium) wire. Less amps, more heat.

jdmumper2 years ago
I like the look of the wood box. It might be fun to hack in a Peltier heating/cooling element. I have no design to offer, but... Here's an example device that will raise the required current to 6+amps, but might be useable with the proper aluminum fins...
man is there any way to increase current in TEC1- 12706 .. I used pc 300w power supply 12v which capable to give20amp but peltier takes only 3amp.
and the other thing to control the temprature on off switch ... i have some thing idea about this but main problen is to draw more current..
swade116 months ago

does anyone know if you can connect a 12volt car lighter to it?

also could you just do the cooler on a 9v battery?

if yes on both i would love to make 1

9v batteries can't provide much curent. I reckon the heating elemement would try to draw more current than the battery can produce and this would mean the fan wouldn't turn at all. It would be a bust. And a 12v cigarette outlet should be able to provide 30 watts. Just chck your fuse first to be sure.

Liam.great983 months ago

how much heat does this produce? I tried a proof-of-concept without the fanc wooden enclosure and the spring was drawing about 5 amps, that's 60 watts, but when the fan blew on it it just cooled it down and barrly any heat was actually blown out by the fan.

Nhoj161 year ago
This is really cool, I'm going to make one for my mom who hates the cold. So not to overcomplicate it can I just hook a computer fan and hair dryer coil to a 12v cord?

I would assme a hair dryer coil is designed to run on mains power (120/240vac) so connecting it to 12v will produce minimal heat.

Peter8802 years ago
UK PWM Fan Controller

Cheap and decent, I bought one ages ago.
Schmidty162 years ago
man i love the look of it i wish i could make one i will try someday
Spokehedz2 years ago
Link to where you bought the PWM dimmer module?
HHarry (author)  Spokehedz2 years ago
(removed by author or community request)
j0npae HHarry2 years ago
I live in the US and I tried looking for this thing and I cannot find it. Are there any alternatives to this piece?
HHarry (author)  j0npae2 years ago
Would this dimmer switch work instead? It isn't labeled as PWM
HHarry (author)  octochan2 years ago
It is really a pity my supplier won't ship outside Europe, it is really a good product. If you are just going to use the fan the dimmer you mentioned (I think) will work. But with the heating element installed the dimmer will burn down. You should calculate how much amps all your components need and than buy a proper pwm controller, but don't spend to much money on it. On ebay type pwm controller.  Here is a similar product  
If 30 watts is working for you, that's great. My experience with portable electric heaters is that they are usually rated around 1500 watts, maybe with a "low" setting of 750 or 1000 watts. I've used a ceramic-element heater which, once up to temperature, would settle down to 400 watts on its "low" setting. This was barely enough to keep a small room warm.
HHarry (author)  RankineCycle2 years ago
Yes, I know It just gives a warm stream of air nothing more nothing less. Just like I said in step 5.
Finally, a project that interests me enough to build. Only thing that concerns me is the safety aspect of it. When I build mine I'll put a couple more of safety features in it.
NightLord2 years ago
Well if you want more heating power, just add some more springs in paralell... just be careful it doesn't heat too much.
scottinnh2 years ago
Congratulations on a polished product and documentation.

Your drilling was perfect not just with pattern spacing, but also for smooth bore holes. Wasn't till I saw the close ups that I could tell it wasn't laser cut.

I'd suggest to anyone else that they clamp a piece of sacrificial board to the front faceplate, to avoid splintering when the drill bit punches through.

Other suggestion is to skip the heating element and buy the right sized 12v light bulb... An incandescent bulb is a heater, light, resistor, and safety fuse all in one.
Yeah, but then it is icky nasty incandescent light blasting out of the vent holes and you wouldn't be able to see the LED.

Also with those long power bus bars you could easily add one or two more springs in there to get a little bit more heat blowing through. Plenty of space in there, but obviously the power requirements go up.

rickharris2 years ago
I might suggest that some nichrom wire would make a better heater element. The spring is likely to fatigue or just burn out .

I would suggest a sensible fuse in the circuit is a good protective device in case of excessive current.

Is putting a heat source (30 watts is quite a lot) in a wooden case advisable?
HHarry (author)  rickharris2 years ago
The spring does not burn down; the fan keeps everything cool. You can see it as a hair dryer: 2000 watt in a confined space still the hair dryer does not melt down.
My design is like putting a 30w light bulb in a open wooden box with a fan on it.

But yes nichrom wire would be a better option. Also a tilt switch is advisable so everything shuts down when the box is putt on his back.
Lunera HHarry2 years ago
Hair dryer coils are made of nichrome. You can find the stuff pretty cheaply online if you look. has a nice calculator for determining how much of what guage you would need for your particular application.
lime3D Lunera2 years ago
Just go to Salvation Army and buy and old hair dryer to hack the coils out of it.
Lunera Lunera2 years ago
forgot to mention, if you do use nichrome, be EXTREMELY CARFEUL, I just thought about the fact that your enclosure is made of wood.
You have made me happy :-)

All is OK - even with a hair dryer - until the fan stops - ask my wife! :-)
longwinters2 years ago
What drew me to your project was the neatly done grill holes, I know it sounds silly but having made a few projects over the years that require evenly spaced holes it's more difficult than you would think. Nice job, if you planned to leave it running while you go on vacation for a month, a thermal cut off fuse is about a buck.

Nice touch with the back lit LED's