There are forum users here that have done extensive experimenting in extreme cold weather conditions and logged a lot of data on hive configurations with heavy  R value insulation and zero upper ventilation. From  discussions i have seen where they are confronted by folks with confirmed belief in upper ventilation being the only way to go, I can understand them perhaps being disinclined to engage. I expect Randy will get some responses off forum.

I have played with the concept for a number of years but only with a handful of colonies and no data logging to speak of.  I will say that the system of dealing with the amount of moisture created by the metabolizing of 50 or more pounds of honey will produce gallons of water that will have  to be dealt with. Venting it off is the old standard and it does work but at the expense of a lot of lost heat.  If the upper hive surfaces and contents are insulated sufficiently they will stay above the dew point and there will be very little condensation on these surfaces.  It is common to insulate the hive front to a lower R value and tip the hive forward. Resulting condensation on this deliberate condensation plane, will run down and out the lower entrance but there will be no dripping on bees.

In warmer climates condensation will run out as liquid water but in colder climates ice will accumulate at times and if not provided for can block standard bottom openings. Lesson learned. I am presently using something akin to a slatted rack to give space for accumulation. Without a large upper ventilation, convection currents are greatly reduced.  Exchange of Oxygen and CO2 takes place at the bottom entrance and there is considerable discussion about the science of it. Enough examples exist to support this. One thing for certain is that maintaining the integrity of this opening is then manditory.

People who are getting satisfactory survival with the present system in growing zones 4 or warmer likely wont be motivated. If it allows a person to winter on a single deep in cold climates rather than needing doubles it might be worth looking into. 

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html