Hi all, We got these rad reflector foils to improve your heating bills in our shop today. Trying to figure out if there any good. As a really quick test to see if they do anything, i stuck one to the kettle and measured the temp difference with a thermal imaging camera. (pics attached) They seem to do something as they lowered surface temp by around 32C which was a 40% decreased compared to the kettle wall. Anyone know how I can come up with an Rvalue (m^2K/W) from this or any relevant way to show that they have some insulating properties. My problem is that the foil has virtually no thickness so I can't do a one dimensional analysis and I don't know of any zero dimensional analysis. I do know that it can have an r value though because air is given an rvalue and there is no dependence on the thickness for it. Any help is much appreciated. I will do it over a range temps if there isn't too much work in it as generally your walls aren't at 80C.