Guru
Joined: 22/10/2019
Location: AustraliaPosts: 955
| Posted: 01:48pm 10 Apr 2021 |
I'm still working on my Warpinverter but it is going to take a little while yet.
In the mean time I have been trying to work out if we can add a little extra heat to our home over winter and perhaps even burn less wood.
The idea has come about due to spotting some cheap evacuated tubes for sale on FB marketplace. I bought a box of 10 initially for $20 and was offered the remaining 100+ for $100.
Unfortunately the tubes come without the copper heat tubes that enable them to transfer the heat out into a manifold to heat water or air ... so it precludes using them to heat water without a lot of extra work or expense, and probably both!
After playing around with the first batch, I've been impressed with the amount of heat the tubes can collect ... so I've been toying with different ideas as to how I might make a practical device out of them.
One of my early experiments involved putting a plastic tube down the centre of an evacuated tube and blowing cold air down it with an air compressor. The ensuing air was far too hot to hold my hand in front of ... and despite it being late afternoon with minimal sun, it took 6 or 7 minutes before the temperature dropped to 30 degrees C. It had started at 70 degrees.
On warm days I've seen temperatures as high as 200 degrees C in the tubes, though of course they are not the days we want more heat in the house. On the other hand, I have seen temperatures still at 45 degrees even at 10 o'clock at night.
Again, that would drop pretty quickly if I tried to make use of it ... but any mildly sunny day during winter has to provide some warmth.
Another reason for going down this track is due to my experience with winter sun here at our home over the last couple years.
We have a couple massive sheds and I enclosed one end for my income producing workshop
... lining and insulating it well. I have always been amazed at how warm it is upstairs above the workshop ... to the point where I piped hot air from just under the peak, down into the workshop below.
I used some thin aluminium from a roll I bought from Bunnings ... and used double sided tape to close in the front of a C-Section post that runs the full height of the shed.
Then I hooked up a bilge -blower type fan out of an old microwave to aim down the post ... dropped an extension cord down the gap as well to make it easy to switch on ... and then harvest the heat from there.
It is not all that fantastic on cold mornings and is not really worth having on ... but by mid morning if there is any sun, it is noticeably warmer having the fan on. The insulation is such that I often turn it off by lunch time otherwise it gets too hot ... depends on the day.
I am hoping that with the efficiency of evacuated tubes, I can amplify that effect manyfold.
In my next post I'll show some illustrations of an idea I've come up with and I'll be interested in some feedback.
Thanks for reading.