Tuesday, January 21, 2014

Final (for now) Bird Bath Heater post

After many redesigns of the heating element I have had no success in melting any ice in the birdbath. I have tested the integrity of the newest element that I made, multiple times, as well as the power coming from the windmill and I can say that the windmill is generating the expected power and the heating element seems to be intact (resistance is unchanged from the calculated and initial measured resistance). It seems that I need either a bigger windmill or even higher gauge (thinner) wire than what I have used so far.

The last heating element I tried was a repeat of the last one only I made it much more compact to concentrate the heat:
Heating Element v3
I put it together using:
I wrapped the Nichrome wire around a short section of wire insulation taken from a hair curler (same one I took the original Nichrome wire from) - I wound the wire as close as I could and then coated it with the RTV silicone. (On the left side of the picture is a tube of RTV silicone (Room Temperature Vulcanizing) meaning it sets and cures at room temperature to become resistant to higher temperatures [this one was rated around 300 degree Celsius)
For clarity, a bigger windmill would mean any of the following or a combination of them:
Larger propeller (bigger swept area)
Bigger motor (larger stepper, treadmill motor – just something with a bigger output)
Higher placement (less turbulent winds)

Other things that would possibly increase effectiveness:
*More efficient heating element
  • thinner wire
  • closer spacing of wire in coil (tighter coil)
  • improve heat conduction from coil to body of element
*Add solar to increase power to heater (likely minimal due to decreased solar radiation in winter)

The windmill itself is undamaged and continu
es to function even after the nasty weather that we've had over the last few weeks. So, I can say the basic design works and I will leave it outside to see how it holds up over the rest of the winter.

I will continue to post over this week to catch up (I've been working on some additional projects)