Helen,
You have modern windows, so many of the issues of
applying film to glass are not as significant. Film applied to historic
glass sometimes causes problems. Yes, film eventually fails. And
then it needs to be replaced. This can be difficult on historic glass and
may even cause breakage of the glass as adhesives become more difficult to
remove with aging. In your case, this is not a problem. Of greater
concern is that manufacturers of films generally (and this varies from
manufacturer and film type) will not recommend application of film to glass that
blocks more than about 80% of visible light. That means that 20% is
transmitted. Ideally, a film should block 95% of visible light, which
means 5% is transmitted. This means that 4 times as much light is
transmitted with film on windows versus other alternatives. Of course, all
of this assumes, as it should, that 99%+ of the UV is blocked.
The solution is to use mylar roller shades that are
capable of blocking 95% of the visible light. The issue with film directly
on windows is that the heat generated by the rejection of light can damage the
adhesive. This concern is eliminated if the shades (film) are not
attached to the glass. Yes, framed systems can be used as suggested by
Dave, but it is less expensive generally to use roller shades. Extensive
experience has shown that bronze color shades appear to the human eye much
brighter than grey color shades. There are many issues other than these
presented here that can impact protection from light damage. It would be
best to consult with a conservator to develop a light control plan. For
example, one of the other options is to install room darkening shades in consort
with the mylar shades to be drawn whenever the building is closed to the
public. 0% light transmission is 5 times better than 5% transmission
with the best shade material. In most spaces, the museum is closed more
hours than it is open during daylight hours (in the northern tier). Spend
money to plan before spending it to implement. Generally no
regrets.
Marc
American Conservation Consortium, Ltd.
4
Rockville Road
Broad Brook, CT
06016
[log in to unmask] Marc A. Williams, President
MS in Art
Conservation, Winterthur Museum Program
Former Chief
Wooden Objects Conservator, Smithsonian Institution
Fellow, American Institute for Conservation (AIC)
Sent: Monday, December 10, 2018 3:38 PM
Subject: [MUSEUM-L] UV Window Film Installation
Hello!
Thank you to all who responded to my post last week regarding exhibit
designers! I'm still working on responding to everyone.
In the meantime, I have another topic: UV window film installation. I've
reached out to 3 companies in the Madison area to request in-person visits for a
walk-through and an estimate. But I wanted to ask if there's any advice for what
to look for in a product and things to think about pre-installation that folks
realized later they should have anticipated or considered?
Also, when doing the UV film, did anyone also add in security or privacy
film?
All of our windows have been installed within the last 3 years, even though
the building is 94 years old, so they are all double-pane windows and energy
efficient.
Thank you,
Helen
To unsubscribe from the MUSEUM-L list, click the following
link:
http://home.ease.lsoft.com/scripts/wa-HOME.exe?SUBED1=MUSEUM-L&A=1
To unsubscribe from the MUSEUM-L list, click the following link:
http://home.ease.lsoft.com/scripts/wa-HOME.exe?SUBED1=MUSEUM-L&A=1