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Posted by z on March 14, 2008, 1:00 pm
> Mortimer Schnerd, RN wrote:
> > aemeijers wrote:
>
> >>Sounds like a market niche to me- an air valve for the door to vent the
> >>overpressure, but fall back shut once door latches? A little flapper in
> >>a tube, light enough that the moving door and air pressure buildup would=
> >>hold it open, but heavy enough to fall back shut, and with a ring around=
> >>it on outside, so that venturi effect of passing breeze wouldn't suck it=
> >>open? There could be a screw-adjusted spring to adjust the tension. Or
> >>maybe build it right into the latch- a vent tube that would be closed
> >>once the striker cycles.
>
> > You could install an exhaust valve from the second stage of any scuba re=
gulator.
> > It's a flat thin flexible silicon rubber disk about the sixe of a quarte=
r that
> > has a central stem also made of rubber. =A0You poke the stem through a 1=
/8" hole
> > in the storm door so that the valve rests flat against the the outside. =
=A0You
> > drill a small 1/4" hole or two underneath the wide portion of the valve =
to allow
> > the air to actually escape; the center hole is already occupied by the s=
tem of
> > the valve. =A0The wide portion of the valve covers the holes until an ov=
erpressure
> > exists; then it blows out of the way temporarily to relieve it.
>
> Have you actually observed that scheme working?
>
> Jeff
>
> --
> Jeffry Wisnia
> (W1BSV + Brass Rat '57 EE)
> The speed of light is 1.8*10^12 furlongs per fortnight.
>
>
>
>
>
> > Or you could just wait until the storm door closed before you closed the=
inner
> > door.- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
ah.... seal both doors and the chamber in between airtight. attach a
vacuum pump to the interdoor volume to pull a vacuum. will not only
shut the screen door tight, but will provide maximum insulation, more
than if you left the air in between.
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