Saturday, Jun 17, 2017 at 23:03
Can't go past a Glind for
mine. You've always got a hot engine, why not utilise that engine heat?
Admittedly, the solar versions are cheaper, but I was happy to fork out the extra for the Glind.
The problem with simple solar setups is that when you really want hot water - on cold days - they are struggling. To get the maximum benefit from a solar setup, they need an arrangement that concentrates the sun's rays.
Maybe a silver-coated reflector surrounding the PVC, at a small distance from it, would help?
I can remember the brother and SIL leaving a stainless steel bowl on the back
seat of the Holden during Summer sometime in the early 70's - with some paperwork placed inside the bowl.
When they came back to the parked car after 45 mins, the paperwork was smouldering!
It didn't take long to figure out that the rounded bowl had concentrated the suns rays on the paper, like a magnifying glass.
The locked car helped too, closing up something prevents the heat getting away.
The latest solar HWS's for houses use evacuated (vacuum) tubes that essentially long thermos flasks.
These are very effective at collecting heat from the sun, and a couple of these would probably work better than the black-painted PVC.
I see where sellers on eBay are now selling solar stoves based on the same principle.
Not sure how effective they would be at getting you a cooked meal on a cold, cloudy, sunless day - but on an average sunny day, I'd expect they'd be quite effective.
Cheers, Ron.
AnswerID:
611968
Follow Up By: Les - PK Ranger - Sunday, Jun 18, 2017 at 09:03
Sunday, Jun 18, 2017 at 09:03
Parabolic shape concentrating the energy Ron.
We make curved glass, convex glass in kilns for various industries.
Over the years I have made many a bend or convex glass for things like bush stills, cookers etc.
I have made numerous concave mirrors for people, take them in the sun they can damage eyes if there is a bad flash, so great care is needed . . . can start wood smoldering in seconds, and not much effort to get a fire going.
The bent glass really works great with concentrating heat on pyro tubing carrying water, heats to steam very fast, they use this sort of thing commercially for electricity generation in some solar plants.
FollowupID:
882013