Tuesday, December 10, 2013

Wood Stove Reco Fan (Build #2)
Scott Symmes3:19 PM

fan-working-on-stove-iPhoneBuild #2 The second build was a success. It was based on the Instructables guide by the author "tinkerme". After reading the guide, I had a hankering to try again.

**Parts List**
Hot side:
- a passive aluminum heat sink from a Power Mac G4 466
It's roughly 3" wide by 6" long, lots of fins. The raised part for the chip, was cut off with a hacksaw and ground down. Upgrade: concerned the heat was slipping through the outside fins. Put a shroud around the hot side of the cooler. This would prevent the loss, and gather the heat. Found an aluminium control box from a washing machine. The shroud also prevented the heat from reaching the Thermalright cooler fins.
- little 1-1/2" x 1-1/2" square piece of copper. It was used as a spacer/transfer sat of heat to the peltier module. Use a copper pipe, cut length wise, pound flat and buffed up on the grinder.
- Peltier module (90 watts, ebay@$19.00) Model TEG1-12710 Note: click here for a good web site about Peltier markings     - 40mm x 40mm x 3.3mm  
  - Power input from 0-16 volts DC and 0-10.5 amps (when used as a thermoelectric cooler)
  - Operates at temperatures as high as +350 deg F  
  - Fitted with 6-inch insulated leads  
  - Perimeter sealed for moisture protection

Zalman's cooler paste **A must have. This grey goop was cheap and was included with most CPU heatsink kits. It really increased the heat transfer and the voltage.
Thermalright CPU Cooler Rated for a 120mm fan. Aluminum base. Well made heat sink

- 1.5 to 3.0 Volt DC Hobby Motor **A must have. The earlier motor, needed a couple of volts to get running. But, hobby motor required 1.5 volts to start. So, I broke the "made-from-junk" rule and bought a small hobby motor for The Source (Radio Shack) @ $4.99 *Note: a standard 4" computer fan didn't work. Not sure how other people can get theirs going?

  - The homemade, 2 blade, prop works OK, but the motor gets only up to .23 volts. Plan to work on it and make improvements
- the cooling fan from a blender gets up to .43 volt, but doesn't push air at a lower RPM
- made a fan blade from a coffee can bottom, works good, lots of shake
- A plastic, 4 blade exhaust fan blade works the best. The only bummer was it's made from plastic and could melt. So, made a heat shield for the bottom.

- Had it successfully working on the December 7th weekend during a record cold snap. Since it was minus 32° Celsius (-25° Fahrenheit) outside, I had the wood stove wide open running as hot as I could.
- Noticed the fan blades started to turn when the wood stove hit 100° Celsius (212° Fahrenheit) 
- Once I realized it was turning the wrong way, I reversed the positive and negative leads. It started to push the cold air through the fins and out the other side.