Doors and Windows - Need window help

We have had new windows installed in our home in (hot) Tucson AZ. Between the panes of glass we noticed screw tips protruding. When I asked the dealer about this I also asked if that wouldn't let out the gas or void the vacuum or whatever was in that space. I was told that it was just air, no vacuum, no gas and that that was the way they were being built now because the gas would only stay for a couple of years anyway. Does anyone know what the (quality) windows (now days) have in that space between the panes of glass? What is best? One more little question, I thought that the 3/4" measurement was the space between the panes of glass but I'm told that it's the distance between the two outside edges, any thoughts on that? Thanks!

Are they really screw tips, or are they more like rivets? Are they only near the corners of the glass or are they at various locations? Some IGU's are designed to have rivets or screws visible near the corners where the spacer comes together so if that is what you're seeing it is normal and nothing to worry about. The IGU is sealed with butyl around the exterior of the glass- that's what seals the glass up. The screws are probably not penetrating anything they aren't supposed to. I believe the Intercept steel spacer is made in this manner if I recall correctly. (correct me if I'm wrong, anyone.)

If you did not order your IGU's with any type of gas fill then what you have between your panes of glass is common air, straight from the factory it was assembled in. Dessicant inside the spacer absorbs any moisture that was in that air so that your IGU does not fog up. The best windows would have Argon (for a 3/4 IGU), or Krypton (in most triple pane IGU). Although offgassing occurs, and estimates vary regarding the rate at which it offgasses, many experts agree that this takes place quite slowly- perhaps as little as only 10% after 10 years. Your automobile leaks freon faster than that. In Tucson, they are probably more concerned about heat gain than heat loss, so you probably don't need gas fill down there- not sure. (Been there several times- have 2 brothers-in-law there)

A 3/4 IGU is 3/4" from outside of glass to outside of glass. The space between the panes is usually 1/2", which is the optimum width for a dead air space. Any larger and convection occurs... any smaller and you have too much radiant transfer.

Thanks for your time and the information. I just needed to hear it from an impartial party.

The real facts are that the first person you talked to was probably correct, the large amounts of heat and cold that are transferred throuhgh the metal spacer in your windows will cause tremendous amounts of contraction and expansion, this will lead to the seals in the windows failing and the gas escaping, once that seal is broken you will eventually get fogging or condensation, but it will depend on the tempeture difference between the outside and inside of your home..the silaca they put in the spacer is there to absorb the moisture the manufacture knows will be present when the seals go bad..bottom line is if you didnt pay atleast 600.00-800.00 per window you probably got a low end builder grade window. the best products availible nowadays are using non conductive non metalic spacers between the glass. a standard energy efficient windw should have a 5\8 inch gap, between the panes..argon would be pumped in one end while air is pumped out the other..in a window with a metal spacer this will be gone in as little as 2 years, a well made window it could last a lifetime..by the way, argon is just as important in warmer climates, it is an inert dense gas(7 times denser than air) and will dramatically reduce the amount of heat that comes through the window..if you can feel alot of radiant heat the windows arent performing..let me know if you have any further questions.

wr