permaculture

[Neil Bertrando <neilbertrando@gmail.com>]

do you have info on sources and materials used in non-toxic pressure
treated lumber?

On Fri, Jan 18, 2013 at 8:26 PM, venaurafarm <venaurafarm@bellsouth.net>wrote:

> On 1/18/2013 11:03 PM, Scott Pittman wrote:
> > I have always read that any airspace between the glass or poly should
> never
> > exceed 5/8 of an inch to prevent a thermal loop from developing which
> would
>
> There is plenty of glass double pane panels that have 3/4" airspace.
>
> > defeat the purpose of double glazing.  This is certainly the rule in
> > manufactured thermal pane windows and doors.  By evacuating the air space
> > between the glazing panels you can slow down this effect with over time
> the
> > vacuum gets lost.
>
> My method just uses two Polycarbonate glazing attached to framing
> members, not air evacuated. My untested theory on prevention of thermal
> loops would be to use more framing members, blocking more light of
> course but creating a stronger panel that is more energy efficient. I
> would not hesitate to use this method on a skylight, in a sunspace or
> or a greenhouse. This by far the cheapest way to go plus extremely
> durable and lightweight; you get plenty of light with some degree of
> thermal efficiency.
>
> LL
>
>
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