ker_01 said:

I have a large picture window that I have a bunch of plants in front of (I
bring them in during the winter, take them outside in the summer). The
plants are tropical fruit plants (mango, avacado, lemon, lime, etc.) and
need as much light as possible.

I'm planning on putting a storm window over the picture window, and I
have
a choice of regular glass and low-e glass. The price difference is minimal,
but before I go with the low-e I want to know if it is going to block
wavelengths that are beneficial to the plants.

There will be some loss of light caused by just by adding a clear storm
window. Any additional loss due to low-e glass will most likely be
very small in comparison to that first loss.

We replaced our windows with new one that have low-e glass and the
house plants have been fine.

Can anyone point me to a relevant resource?

Here's some info on light transmissibility:
http://www.efficientwindows.org/lowe.cfm

A manufacturer answers FAQs he
http://corporateportal.ppg.com/NA/Id...ss/lib-faq.htm

From that page ("Will PPG Low-E glass affect my plants?")

"The wavelength of radiant energy used during photosynthesis is between
320 and 700 nm.

"The maximum % energy transmitted by SOLARBAN 60 coated glass,
for example, is between 400 and 700 nm, the same energy range as
that primarily used by plants. For comparison, the total visible light
(380 to 770 nm) transmitted by a 1” clear insulating glass unit (2 lites
of ¼”clear glass with a ½” airspace) is 79% versus 69% for a similar
unit with a SOLARBAN 60 coating. While this is a decrease in useful
solar energy being transmitted, it is less of a decrease than going from
unobstructed outdoor growth to growing behind clear glass, or the
reduction that may occur simply by placing plants further from the
windows.

"In general, most plants that can be grown behind a clear glass window
would also be expected to grow behind SOLARBAN 60 coated glass units."


--
Pat in Plymouth MI ('someplace.net' is comcast)

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)