Re: [GBlist] Windows & UV Damage

[John Salmen <terrain@shaw.ca>]

I think you have to be careful here and consider how the rooms will be used.
There will be no gain if a homeowner or future homeowners have to shutter
the light out in order to use the room. The light can be pretty intense.

The other consideration is that uv degradation of materials and finishes can
contribute substantially to iaq problems.  Window placements directed
immediately to surfaces that can provide solar gain without too much
degradation and that can also bounce the light are useful as clear glass but
windows that one lives next to that are in the path of people, and objects
are something that are inevitably curtained to maintain comfort so might as
well build that into the window.

it is one of those difficult things to plan for with too many perspectives
too consider.

John Salmen
TERRAIN E.D.S.


----- Original Message -----
From: "Sarah Holland/David Foley" <hollandfoley@acadia.net>
To: "Greenbuilding" <greenbuilding@crest.org>
Sent: Wednesday, March 27, 2002 8:04 AM
Subject: [GBlist] Windows & UV Damage


> Dear Folks,
>
> We're running some calculations that show us that we can lower the annual
> heating needs of a house in Maine by about 18% if we merely switch the
> south-facing windows from low-E glass with a low solar heat gain
coefficient
> to clear insulating glass with a higher SHGC.  (East, west and north glass
> would remain low-E.  We haven't yet calculated if this change will
increase
> cooling loads in summer.)  Making this change is about the only glazing
> option available to us with this window manufacturer.  My question is:
> where can I find good data on the potential for UV damage to fabrics,
> upholstery, etc., from the clear insulated glass?  There's an index,
called
> the "Krochman Damage Function" which is a percentage of transmission of
the
> UV spectrum, compared to outdoors.  The number is 64% for clear IG, and
34%
> for the low-E glass.  But what does this mean in practical terms?  Would
the
> owners anticipate much more damage to the contents of the house?  Any
> real-world experience or hard data would be appreciated.  Thanks!
>
> - David Foley
> --
> Holland & Foley Building Design L.L.C.
> 232 Beech Hill Rd.
> Northport, Maine 04849 USA
> p: (207) 338-9869 f: (207) 338-9859 e: hollandfoley@acadia.net
>
>
> ______________________________________________________________________
> This greenbuilding dialogue is sponsored by REPP/CREST, creator of
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> ______________________________________________________________________
>


______________________________________________________________________
This greenbuilding dialogue is sponsored by REPP/CREST, creator of
Solstice http://www.crest.org, and BuildingGreen, Inc., publisher of
Environmental Building News and GreenSpec http://www.BuildingGreen.com
______________________________________________________________________