As a disclaimer, this is my first official post here, but a long time ago, in a site far far away, I wrote the original “cut and paste” that Thor posted to open this thread, I am not sure if that should count as my first post or not.
Anyway, to be honest I found this site/thread entirely by accident while looking for something else at the time, but when I started reading I realized the original cut and paste was mine. And while I enjoyed reading the entire thread, I did notice a few misunderstandings or discrepancies that I could address in the hope that someone may find my comments helpful.
I wouldn’t have reopened a 6 year old thread, but since there were entries up to late 2017 there does appear to be some interest in keeping it alive at some level.
Okay and to start, there are glass companies and there are window companies. Glass companies don’t make windows and window companies don’t make glass. Andersen and Old Castle were mentioned several times in comparison, but that really isn’t accurate because Andersen is a window company and Old Castle is a glass company (among a few other things).
The primary residential glass companies in North America are Cardinal, Guardian, Pilkington, PPG. Note I didn’t mention Old Castle? they are a glass fabrication company, meaning they do stuff with glass that they buy from one of the actual glass companies, but don’t actually make glass.
The others I mentioned all make glass from sand and other stuff. Cardinal is by far the largest contributor to the residential window market. They make the glass and sell it to window companies, but they also coat it (about 70% of residential coatings come from Cardinal), temper it, laminate it, and make it into dual pane or Insulating Glass Units for a crap-load of window companies.
In the residential world, the distinction between window manufacturer and glass manufacturer is fairly well defined, but in the commercial world its a bit fuzzier. But that’s just details. A great many window companies (especially smaller ones, but a few big ones as well) buy glass and make their own IGU’s. No window company coats their own glass, but many temper glass and a handful laminate their own glass as well.
As mentioned in the first post there are two versions of LowE coatings - hard coat and soft coat.
It’s common knowledge among glass professionals that hard coats can be exposed and soft coats must be protected either between the lites of and IG unit, or else inside a laminated unit. You cannot expose a soft coat LowE coating or it is going to be destroyed, and once upon a time it was that simple…however…not everything is as it seems (sometimes).
Hard coat = pyrolytic (or vapor deposition), meaning “exposed as a fog and then cooked on to the glass surface while the glass is still molten in the float process”. Typically Florinated Tin Oxide, often with other junk added.
Soft coat = Magnetron Sputter Vacuum Deposition (MSVD), meaning finished glass pushed through a series of vacuum chambers filled with various gasses and plasma’s where the metals and metallic oxides of the coating are applied atom by atom. Usually silver being the operative ingredient, but could also be stainless steel, or titanium, or even gold for some specialized applications.
Simple stuff, right?
Okay, so when talking about surface 1 or 4 coatings it used to be all about the above, hard coat typically 1&4 while soft coat 2&3, but then Cardinal Glass (the 800lb gorilla of the residential glass world) developed sputter coatings that could be applied to surface 1 and 4. Specifically NEAT for surface 1, which is Cardinal’s version of the “easy clean” coating, and I89 which is a surface 4 coating developed to improve U-value of glass.
So while these new coatings were technically soft coats, based on the Magnetron Sputter Vacuum Deposition (MSVD) definition, they were developed to be on the exterior surfaces of the glass.
So when talking about Andersen, Marvin, Pella, plus the majority of the next few hundred of the biggest window companies, you are talking about Cardinal Glass and you are talking about I89 and NEAT exterior coatings.
oh and as an aside “Please note, the source of this information does not come from an official or trusted source.” from the original post. I am not official of course, but I like to consider myself reasonably trustworthy.
okay back to it.
Andersen’s LoE4 did not mean four coatings. In fact AW LoE4 had two coatings - an actual low emissivity coating between the lites of the IGU - typically Cardinal LoE²-272 or LoE³-366. The second coating was NEAT on surface 1. The other two items on the “4” of LoE4 were argon gas between the lites to improve U value and the plastic film placed on the glass at the Cardinal factory to protect the glass during manufacture and shipping and installation - called Preserve.
When cleaning glass, you CANNOT damage the LoE coatings between the lites of the IGU, but you CAN damage the coatings that are on the surface of the glass.
If in doubt over how to clean them ASK!! As was pointed out by other posters.
So a few lines back I called NEAT as “easy clean” coating and not self-cleaning. That wasnt an accident. Cardinal has never considered NEAT to be 'self-cleaning". They always considered it as easier to clean glass.
As pointed out in other posts, the surface 1 coating is primarily titanium dioxide. Cardinal applies it as a sputter coating while Pilkington, Guardian, other glass companies, apply it as a pyrolytic. Pilkington (among others) refers to the coating as self-cleaning, but that can be misleading. And btw, the sputter version is much smoother at a microscopic level versus the pyrolytic version.
In order for the coating to “clean the glass” it needs direct UV exposure and it needs water, be it rain (self cleaning) or a garden hose (easy cleaning). AND it is not impossible that it might need a cleaning solution and a squeegee on occasion when it’s really dirty.
The coatings need UV to oxidize organics, basically cooks the dirt (called Photo Catalytic Oxidation - memorize that one and mention it to your clients when you are quoting a job. That’s gotta add a couple bucks per window just because it sounds so cool!).
So what about inorganics? The coating does make the glass "slippery’ (think of it kinda like teflon in a pan, but not exactly that) so its “easier clean” for someone cleaning the window to remove the inorganics versus ordinary glass. But once again, FOLLOW DIRECTIONS!
Once the UV has finished Photo Catalytic Oxidationzing the organics you spray it with water and wooooosh all the dirt rinses off and the glass dries clean. But why?
Ever use RainX? RainX brags that it makes glass bead up on a surface, and it does that really well because RainX is hydrophobic, meaning it repels water. Beads are cool, water beads on glass or on your new paint job are cool too, until the water evaporates and leaves all sorts of minerals behind. Be it the glasses in your dishwasher, your car’s windshield, that window that you just cleaned to crystal clarity before it rained…water spots, and the homeowner or building manager is asking you what YOU did wrong.
The surface 1 coatings are hydrophilic, meaning they like water, they don’t repel it. Water spreads out on a hydrophilic surface because of low surface energy. so it sheets taking all those water-spot-causing-minerals along with it. Including the organics that the coating previously oxidized. Clean glass, no water spots when it rains right after you finished cleaning the glass to crystal clarity. Happy homeowner, happy you.
And btw what if the glass surface doesn’t receive enough UV light from the sun for the Photo Catalytic Oxidation to take place? Shade tree, wrong exposure, shadows from the neighbor’s house, whatever blocks the UV from reaching the glass. Well in that case there ain’t no Photo Catalytic Oxidationizing happening so the coating isn’t cooking organics and those uncooked organics ain’t rinsing off the glass when it rains. Get the picture? Glass needs cleaning the old fashioned way…BUT it’s still slippery and water is still going to sheet, so it’s still EASY to clean…but FOLLOW DIRECTIONS and you are looking to save time and energy and have a very happy homeowner if you do it right.
This glass isn’t going to replace window cleaners, but it may help a professional clean more windows in less time, if you do it right.
Glass companies and window companies are your friends…they want happy homeowners as much as you do. If you have questions ASK THEM, make a phone call. I promise you that the guy or gal you talk with at the glass or window company wants you to succeed, because when you do it’s a win for them too. Trust me on that one!!
and sorry for the typos and rambles…