Keith~
There is a demo that I do, sometimes several times a day, for people who are considering replacing their windows.
I take 3 small insulated glass units, about 6"x6" each, and stand them up in front of a heat lamp. I then take 3 radiometers and place them behind the little windows. Each window has a different kind of glass.
Window #1- has regular insulated glass. Double pane, thermal break,...a good old fashioned thermo-pane window.
Window #2- The first generation of Low E glass. A single coating of silver oxide on one of the two panes of glass.
Window #3- The new stuff. Low E2 Argon. Both pieces of glass coated with silver oxide, and the air between them replaced with the more inert argon.
Turn on the heat lamp.....
Window #1's radiometer starts spinning around like a helicopter blade. Fast. No reflected heat at all.
Window #2's radiometer rotates, but very slowly. We're getting there. Heat being reflected away.
Window #3's radiometer barely turns at all. 88% heat reflectivity. It's freaking awesome stuff.
The problem when I do this demo is that people get transfixed by the radiometers. They probably did, or saw, science projects when they were kids that utilized them. but seem to have forgotten how they work.
There I am trying to explain why the Low E2 Argon glass unit, the one with the non-spinning radiometer is the shit, but all they want to ask me about is why the little propeller inside the radiometer spins.
"It's the heat from the lamp. One side of the propeller blade is painted black, and the other side is painted white. The black absorbs the heat, and the white reflects it. (the simple, but slightly inaccurate explanation) That causes it to spin. Now, getting back to the one that isn't spinning....the one I'm terying to sell you...."
It's no use. I can't figure out a way to get them to stop staring at the spinning little propeller.
People find heat transference fascinating, and they don't seem to be too interested in hearing my explanation why, in this case, we want to interrupt that heat transference.
"88% people!!! That translates to lower heating and cooling bills. Summer sun heat gets bounced back outside, making it cheaper to cool the house. Winter furnace heat gets bounced back inside, making it cheaper to keep the house warm. All because of these silver-oxide atoms that coat the glass...."
Like talking to a kid in a toy store. I have to turn off the heat lamp and make the radiometers stop spinning before I can even begin to get their attention back.