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.
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).
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.
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.
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.
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.
Gently sand the whole cube.
As finishing you can apply wood wax.
Well, that’s it. After the hard work making this you can relax and enjoy the gentle breeze of your just made desk fan.