Low-e coatings question

November 29, 2006

The house im living in with the gf has a ton of glass and ive been putting up lulu dr35. It seems like the house has low-e glass on only the southside of the house.. The glass at night has this greenish/purplish hue to it. Now inspecting it by the n@ked eye I cant tell what surface its on.. Im scared that its on the #4 side facing me and Ive scraped it with a triumph blade. Can this coating be scraped off on accident? What I dont understand is why some people think that putting up film on top of a low-e coating will ruin performance.

I need some true insight on this. I know there are poketdetective type meters that tell what side the coating is on. Also what is the difference between low-e and low-e2(squared) F2G charts state that its important to know.. And finally why dont they just stamp the glass with something stating its low-e

TINT · November 29, 2006

vclimber?

I cant help on this one, I dont do much heat preserviing films out here :DD

November 29, 2006

If there is a low E coating on surface #4 and you put a Triumph blade to it, you will know. It's not easy to scrape off but it does get messed up. If you put film over the coating it will look bad and negate the low E properties of the glass.

There are a few meters on the market to detect coatings. I think mine is called "E-Tech" or something like that. Low E is a coating on either surface #2, #3, or #4 that reflects far IR back into the building. Low E2 is a coating on surface #2 & #3 and not only reflects FIR back into a building but also reflects incoming IR from outside of the building. Low E2 is pretty efficient glass, most of the time there is no need for film on Low E2 unless you want to change the VLT or reject more UV.

Sometimes they do stamp the glass with an arrow pointing to the coated surface, but a lot of times they do not stamp so a meter is a must have. If you are on a budget, you can use a ligther but it is difficult to pick which surface the coating is on that way.

November 30, 2006

It's rare to have the coating on the #4 surface, So I belive you will be okay

November 30, 2006

Take a butane lighter and hold it up near the glass while lit.

Look at the 4 reflections and look to see which one is messed up compared to the rest.

There you go.

TINT · November 30, 2006

November 30, 2006

Don't burn yourself Tint! :thumb

TINT · November 30, 2006

Don't burn yourself Tint!

no im not!

I just dont get this technical when it comes to installing papers :thumb

like I said, thank god I dont deal with LOW E, if I do, you the man to talk about if I need help :beer

tint_detective · November 30, 2006

If there is a low E coating on surface #4 and you put a Triumph blade to it, you will know. It's not easy to scrape off but it does get messed up. If you put film over the coating it will look bad and negate the low E properties of the glass.
There are a few meters on the market to detect coatings. I think mine is called "E-Tech" or something like that. Low E is a coating on either surface #2, #3, or #4 that reflects far IR back into the building. Low E2 is a coating on surface #2 & #3 and not only reflects FIR back into a building but also reflects incoming IR from outside of the building. Low E2 is pretty efficient glass, most of the time there is no need for film on Low E2 unless you want to change the VLT or reject more UV.

Sometimes they do stamp the glass with an arrow pointing to the coated surface, but a lot of times they do not stamp so a meter is a must have. If you are on a budget, you can use a ligther but it is difficult to pick which surface the coating is on that way.

Isn't there a standard as far as, which surface is coated, according to region?? :twocents

November 30, 2006

Isn't there a standard as far as, which surface is coated, according to region??

That's a good question t_d.

The U-Value of the unit will be the same whether the coating is on the #2 or #3 surface; however, the SHGC will be lower when the coating is on the #2 surface.

Here's the guideline for regions:

In general, if you are concerned about reducing solar heat gain (typically in a cooling climate), then using the coating on the #2 surface would best meet the requirement. On the other hand, if you are interested in utilizing passive solar heat gain (typically in a heating climate) then using the coating on the #3 surface would best meet the requirement.