Re: energy-efficient windows

[Brian Whatcott <betwys1@SBCGLOBAL.NET>]

A popular history with some slight relevance:

Once incandescent lamps were vacuum filled.
Then a nitrogen back fill increased life by reducing filament sputter.
But more energy was convected / conducted to the envelope.
Coiled coils helped conserve heating effect.

Then an argon, or better, a krypton fill was introduced,
to reduce heating of the envelope.

If envelope temperatures were not so high, it's possible that a plastic
jacket would conserve more energy inside. This might be the basis of
the e-coatings, possibly?

Musings on triple-glaze.
If double glazing reduced aperture loss by 50%, then another double glaze
would arguably reduce it another 50%, an aggregate of 75% reduction.
But if the break even period were 7 years for double, then for two double
glazes, it's conceivable the payback period would be  21 years.
That's too long.

Brian W

At 04:52 PM 2/21/2004, you wrote:
> How important is filling the space between two panes of glass with argon or
> krypton, compared to low-e coating(s)?  Are two low-e coatings (on
> different surfaces) twice as good as one?  Does it matter which surface the
> low-e coating goes on?
>
> One guy wants to sell me replacement windows with two low-e coatings but
> filled with air; another guy wants to sell me windows with a low-e coating
> and argon-fill (both claimed to have an energy star rating).
>
> Are all low-e coatings the same or equally effective, or do I have to ask
> exactly what the multiple layers are?
>
> Are triple-pane windows enough better than double-pane windows to consider?
>
> Thanks,
> Larry


Brian Whatcott    Altus OK    Eureka!