#Plate glass windows r value keygen#
An air gap is always an excellent insulator and when combined with a Low-E coating this test proved it with a nearly 3✯ drop from the 3rd place finisher.ġst Place – 5/16″ Laminated Impact 84.2✯ Well played, Low-E.Īny of my readers know I am not a fan of IGU’s (aka disposable glass) because of their limited lifespan, but I cannot deny the fact that they do an excellent job (while they are still functioning) of stopping heat transfer. The thicker 1/4″ glass helped I’m sure, and I think the Low-E coating made an additional improvement that kept it below 90º.
I was really impressed with the performance of the Low-E coated tempered glass. I’m not terribly surprised, but feel like in addition to the sound benefits it affords, this increased conductive heat blocking is a nice side benefit. I use 1/4″ laminated glass a lot and was very curious to see where it fell in the rankings. Again, the thicker the glass option you choose, the slower the heat transfer you can expect. The added thickness is what I would attribute this improvement to, not the age. Predictably the modern double strength glass came in just ahead of the antique glass. There are varying thicknesses of antique glass, so thicker versions would likely yield better results and thinner would likely yield worse. Though I love it, it is the least energy efficient when it comes to conductive heat transfer. It’s thin and it serves to simply let light in and block the elements. It was no surprise to me that antique glass conducts a lot of heat. The Speedheater runs at approximately 400✯, but I was unable to get a precise temperature reading beforehand because The FLIR camera peaks at 302✯ which seems like an odd temp to end at, but hey, that’s what FLIR decided to do for this entry level camera. I measured the temperature in the center of the glass on the inside (the side opposite the heat source). The glass all measured approximately 82☏ prior to the test, as they had been resting in my muggy shop for a number of hours. I set an Original Speedheater Infrared Heat Gun 10″ away from each piece of glass and left the glass in front of the heater for exactly 1 minute before measuring the temperature with a FLIR TG130 Spot Thermal Camera. So, let me stop yammering and get to the test results. The testing I did for this post reflects mostly conduction and some radiation. Heat transfers via contact from the stove top to the pot to the water and the water boils. Conduction – This what happens on your stove.Convection requires air exchange for the heat to move. Convection – This is hot air moving in and out of all the gaps (large and small) in your house.Radiation – This form of heat comes directly from the sun’s rays and moves through building materials with ease, unless it is stopped by a radiant barrier like foil.Understanding the 3 Types of Heat Transferīasically, there are 3 ways heat moves from one place to another. I’ve written about the 3 different types of heat before, and you can read it by clicking the link below for a more in-depth explanation. Walls, siding, plaster, insulation, those are all intended to keep us warm and safe inside, but glass does not serve that purpose as its primary function, so let’s not try to put a square peg in a round hole.ĭo we want glass that excels at keeping heat in its place? Absolutely, but before you go comparing the R-value of glass to spray foam, think about their very different purposes. They’re all bad! Glass is not designed to be energy efficient. Comparing the energy efficiency of one glass to another is like comparing gas mileage between mega yachts. Marketers talk about insulated glass or energy efficient glass, but in my opinion it’s all smoke and mirrors. I’m just a historic restorationist and this anecdotal test gets me close enough to see how each piece of glass performs so we can make better decisions when it comes to upgrading the efficiency of your old windows and doors. I’ll preface this with the fact that I am not a scientist and this test is not scientific. This week, I’ll reveal the results of my thermal testing to see if there really is such a thing as energy efficient glass. Last week I had a blast destroying a bunch of glass samples in my shop for Part 1 of this glass series.