Design Green Design Heated Glass: Could This Be the Least Sustainable Building Product Ever Invented? By Lloyd Alter Design Editor University of Toronto Lloyd Alter is Design Editor for Treehugger and teaches Sustainable Design at Ryerson University in Toronto. our editorial process Facebook Facebook Twitter Twitter Lloyd Alter Updated October 11, 2018 Promo image. ESG Share Twitter Pinterest Email Design Tiny Homes Architecture Interior Design Green Design Urban Design That may look like regular glass in that giant window, but it isn't; It is a new way to make windows bigger than they should be and to waste more energy. ESG Thermic heated glass lets you "transform windows from the main source of heat loss in the home to a core heating source of a property" Transparent Heating Element ESG/Promo image It does this by turning the inner sheet of a double glazed window into a transparent heating element that can pump out up to 500 watts per square meter. So if money is no object and you want to do floor to ceiling, or even glaze the ceiling, you no longer have to worry about pesky drafts or cold spots near the window, since the window is actually a giant toaster. Although the outer pane has a reflective coating, this thing is probably going to pump almost as much heat outside as it does inside, yet they claim that it "provides an extremely effective radiant heat while saving dramatically on energy use." However it "removes the need for unsightly radiators with its innovative, invisible, space saving andeco-efficient properties." Few Reasonable Applications ESG/Promo image I must be missing something. How can putting a heating element 16 mm from a single pane of exterior glass save dramatically on energy use? Perhaps a case can be made that under certain circumstances, that's all the heat you need since you are putting it right at the source of the problem. However this lets a designer install windows larger than could possibly be comfortable because of the heat loss, (as most conservatory and greenhouse roofs are) and then solves the problem by throwing half a kilowatt of power at every square meter of it. I can see a few specialized uses for it, such as swimming pools or other very high moisture areas where it could totally kill condensation, But otherwise it is a product just waiting to be misused. UPDATE: I wrote about a product like this before: Throw Energy Out the Window With Thermique Heated Glass. A commenter noted then: Heat transfer always occurs from a hot body to a cold one, a result of the second law of thermodynamics. - so most of this will simply go straight out through the window. What a dumb idea!