Testing Reflective Materials
by Jim La Joie, All Season Solar Cookers
The All Season Solar Cooker is a work in progress.
Recently I experimented with a new reflective material - radiant barrier.
Radiant barrier looks like a woven poly tarp but it is coated with aluminum on each side. I liked the durability of this material and, since it was relatively shiny, thought it might work for solar cooking.
Radiant barrier does not perform as well as the aluminum foil tape that I have been using - and difference in performance is significant.
For the test I used one liter of water in matching pots. The pots were placed inside the ASSC cookers. One cooker's reflectors were built with aluminum foil tape, the other with radiant barrier. I measured the temperatures every 15 minutes and re-adjusted the cookers when necessary.
Results: The aluminum foil tape brought the liter of water to a boil almost twice as fast as the radiant barrier.
For now, I will stay with the aluminum foil tape.
I have also used aluminized polycarbonate film for my solar cookers. I don't anymore. This reflective film works well at first, but it scratches very easily, cannot be re-polished and the aluminum coating tends to separate from the film after a few months. Whether this separation is due to sunlight or the glue that I use I do not know. But I no longer use the reflective film because it cannot be restored once dulled.
Does anyone know of a very bright, durable, renewable foil? I am still searching for a mirror-like finish.
Thank you very much for this valuable information, this should be very helpful to those who might be looking at reflective material options and their abilities to perform.
I found it very helpful myself.
I wish I knew where to obtain a foil such as you described, that can be "re-polished".
The material closest to this capability on the market that I have hear of is offered by Derris of Cleardome Solar.
I will say though that the material is not cheap.
For those who may not be aware,on our site we offer an adhesive material that is quite reflective and pretty durable for use on solar reflector panels and such.
Of course there is no perfect "shiny" reflective material, ours is a good economical reflective vinyl
We will continue to search for better and higher quality products for the solar cooker market.
Please share with us any new and innovative information you wish on you solar cookers and solar cooking in general.