In article 1137696109.400984.229580
@o13g2000cwo.googlegroups.com,
says...


Actually if you look for the injection holes you will see if they are
argon filled.

Good point - but you would have to de-glaze the window
to do the check.


Basic double glazed windows are made with the normal
spacer bars. Those that are intended to be argon filled will have two
rubber bungs inserted into the spacer bar. Double glazed window is made
as normal. Then using the rubber bungs probes are inserted and argon
process is done. I was under the impression that the process reduced
the u value by 0.1.

The industry standard target for Argon fill is 90% of
the available volume. This is rarely reached on the
average production line.

This from FENSA:

"Comment:

It should be noted that there is a barely tangible
difference between the performance of air filled and
argon filled double glazed units.

Because the process of filling double glazed units is
not entirely accurately calibrated and that the process
generally involves drilling and re-filling of holes or
corners to the double glazed unit, leakage is more
likely than an air filled double glazed unit.

It is therefore recommended that replacement windows
have a gap of 16mm or more and that low E glass is used
in a conventional air-filled double glazed unit."


Tests by Pilkington have shown that, although the life
of an Argon unit could be up to 20 years, test units
have leaked all gas in as little as 3 years.

--
Ziggur

"S'ils te mordent, mords-les"