To each his own, but I think that we lack both hard facts
and plausible explanations of mechanisms that I would "buy"
to support any of the following claims:

a) That airflow in a hive is a "convective loop"
   when there are bees in the hive, and the hive
   is subjected to environmental forces (wind,
   temperature fluctuations, etc).

b) That follower boards creating a slightly wider
   space between the hive body and the first interior
   surface than a comb would, and on only two sides
   of the hive, are enough to eliminate problematic
   "roof condensation" in a hive under a wide range
   of conditions.

c) I might be more inclined to believe (b) this effect
   were enhanced (or only detectable) if one SIDE of the
   hive was facing south, and hence the larger space was
   exposed to the warming of the sun, but no one has claimed
   this, and most folks are not going to want entrances that
   face east or west, especially in winter.  (Don't flame me
   pallet users, you have allowed "packaging" to override
   optimal conditions for the bees in my view.  It is a fair
   tradeoff, it just ain't "optimal".)

As luck would have it, we are blessed with the presence of
Jerry Bromenshenk, who seems to have as many wires in some
of his hives as bees.  :)

We are also blessed with Lloyd, who is smart enough to see
the implications of all this for his Ross Round supers, and
is wondering if he REALLY should be telling people to use
7 plastic assemblies per super, rather than 8, and likely
has sketched a new "adapter kit" with bigger spaces at
the sides of the super to test against his current "8-frame"
approach.

Jerry has a buddy (Robert Madsen) who is running a study that
appears to support the "convective loop" contention.  Problem
is, my PhD is in physics (rather than beekeeping), and I don't
"buy" extrapolation of small-scale airflow within a limited
space based upon nothing more than temperature measurements
with thermocouples.  [I call George Imrie as a cooborating
expert witness on this point, but only if he promises to stop
leaning on the caps lock key!  :) ]

So, let's help Madsen out, and suggest an improved methodology
for his study that will allow him to have much more "bullet-proof"
data, by doing a cursory cross-check of his existing data set
with data from sensors that really measure both humidity and airflow.
(If Madsen is not interested, Lloyd may want to fund Jerry to do
this work...)

MOISTURE

This one is easy.

The lab's "quartermaster list" database includes one of these,
as someone apparently ordered one for some reason, and it now
sits on a shelf in the stockroom:

  10-90% Humidity Sensor  BC1333-ND $11.94  www.digikey.com

Hey, that sounds like just the ticket!  A cheap, small sensor
that can detect "humidity"!  Never used one before, but there
it is, waiting to be played with.  Perhaps Robert Madsen can
be convinced to add some of these to his hive instrumentation.
(There are likely lots of other similar sensors out there.)

AIRFLOW

I also said I don't like "airflow" data that was extrapolated
from mere temperature readings from thermocouples.  Why?
Because it is so easy to directly read airflow, all cars made
in the past decade or so have "mass airflow sensors". The
better/newer ones are 100% solid state.

I don't have a specific off-the-shelf low-cost sensor to suggest
here, but there are several lab-grade sensors, and I'd bet that
one could find a mass-produced automotive sensor that was both
cheap and sensitive enough to read the very slow, gentle airflow
claimed to exist in beehives.

To explain how it works, in a "hot-wire sensor", air flows around
a wire heated by a tiny electric current. The wire is kept at a
constant temperature by the current, as the temperature of the wire
determines the resistance of the wire, and thereby, the current.
(In other words, the wire is a "lousy" resistor for any other
practical electronic application except this one, as it has a serious
problem with "temperature drift" that is being exploited.)

As one gets increased air mass flow (more volume, or colder denser,
air) past the sensor, convection heat transfer from the wire to the
air is increased, and more current is required to regulate the
temperature. The current requirement thus acts as an index. It is
converted to a voltage signal which is then used.

In general, the power (volts * amps) required to keep the "hot wire"
at the same temperature is proportional to the square root of the
airspeed (King's law).

So, there ya go... any takers?

          jim  (Who thinks that there is a fine line
                between optimism and self-delusion
                about simple models of anything that
                goes on in a beehive.)

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