I am intensely interested in this discussion and it has reminded me of
questions I have that have been unanswered for years.

As background, Styrofoam is a brand name for a type of expanded
polystyrene.  What I know about it is primarily limited to what I learned in
the development of the BeeMax styroform hive when Bob Stevens, then owner of
Betterbee, Nick Dadant and I spent considerable time with two prospective
manufacturers in order to come up with specifications and costs.
Polystyrene comes to the plastic manufacturers in the form of minute
granules of plastic.  In very rough terms, these granules are heated, mixed
with air (thus, the phrase 'expanded polystyrene', and cooled to form the
final product.  A high-quality final product will float 'high' on water,
meaning there will be little absorption, and will have a outer finish that
is relatively resistant to chipping or denting.  (As originally designed,
the BeeMax products were very high quality.  Based solely on comments by
others, I would say that the quality has since decreased but have no
personal knowledge of that.  My personal BeeMax-type products are as good
today as they were 10 years ago!)

I have had personal contact with beekeepers in the northern US and Northern
Scandinavia (outside of the area of major Gulf Stream influence) and both
claim no problems with winter condensation despite a complete lack of
upper ventilation.  To put it mildly "I don't understand".  The
expanded polystyrene boxes and tops seal up really tight.  Much tighter than
a wood hive.  Why doesn't condensation occur and the subsequent moisture
harm the bees?

My Finnish contact claims that condensation does occur, but runs down the
insides of the hives (instead of dripping from the top) and out the entrance
or the screened bottom.  My Minnesota contact says that there is no
condensation because the warm moist air inside the hive never makes contact
with a colder surface to precipitate the moisture.  To me, neither
explanation makes sense as a 2" thick (high quality) piece of expanded
polystyrene only has an R factor of 8, which does not seem nearly high
enough to prevent condensation and I just don't understand why condensation
in a Styro hive would run down the sides instead of dripping from the top.

Anyone have difficulties using Styro hives without upper winter
ventilation?  Anyone help my understanding of what is going on, or does
anyone else agree that the apparent lack of harmful condensation is a
mystery?

Lloyd

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