Jim,

Are you working with an architect knowledgable about glass and window
specifications and your building?  He/she should be able to help you
with this problem.  Tinted glass can be very unfriendly looking, and if
your building is historic, it may also look odd, especially if new
window frames and mullions are also very different in proportion to the
originals.  An alternative I often specify when we want the benefits
without the discoloration is clear glass (or very lightly tinted)
insulating units with a low-E (emissivity) coating on the inside.
Viracon makes this product and it is relatively expensive glass.  The
shelf life of the applied films may depend on the exposure of the
window, your interior conditions such as the extent of condensation on
the glass, and on whether people can reach it and help peel it off when
it inevitably starts to come loose.

We once specified some extra thick and expensive plexiglas for an
ornamental item at a museum and the manufacturer turned out to be a
museum supporter and I believe donated it.  You might investigate that
route...

Ann Trowbridge, AIA
> -----Original Message-----
> From: Jim McCabe [SMTP:[log in to unmask]]
> Sent: Friday, June 05, 1998 3:30 PM
> To:   [log in to unmask]
> Subject:      Window glazing specifications
>
> We are preparing specifications for new insulated glass windows to be
> installed in the Henry Ford Museum building.  We are looking at a
> couple
> of options for UV filtering and light reduction glazing and are
> interested to know what experience/analysis/thoughts others might be
> able to share with us.
>
> We are currently looking at two options:
> *       A laminated glass composed of a plastic UV-filtering film
> sandwiched between two sheets of tinted glass.  The performance
> characteristics of this laminated glass are similiar to UF-4 plexi.
> *       UV filtering film applied to tinted glass after the windows
> are
> installed.
>
> Has anyone done any studies or had any experience with the
> performance,
> long term effectiveness, useful life etc. of either of these systems?
> In the literature I've reviewed, there doesn't seem to be any
> concensus
> on the lifespan of the UV films; have I missed something?  I've never
> seen anything written on the laminated glass systems, though logic
> would
> suggest they would last longer than the applied films.
>
> The laminated glass has a single supplier and we are expecting to have
> to pay a premium for it.  We are wondering what kind of fallback the
> applied film represents if we have to start reducing costs.
>
> Any good ideas outside of these two options are also welcome.
>
> Thanks in advance.
>
> Jim McCabe
> Manager, Collections Care
> Henry Ford Museum & Greenfield Village
> [log in to unmask]
> 313-982-6078
>