Re: Polystyrene hives
All polystyrene is not the same. I've seen some that were junk. The polystyrene currently sold by Betterbee and Dadant are absolute top quality. I had a hand in their development and can tell you the quality is only because Betterbee and Dadant insisted that it be there. In fact, these are so dense that the supplier initially said it could not be done!
For a hobbyist it is hard to find a reason not to use them. For a commercial guy who wants to bounce them off trucks, etc. it is another matter. I especially encourage women to try them because of the lack of weight.
All that said, they are not all that much better than wood for overwintering. I recall the R-factor for wood is .5 per inch of thickness. The super-dense Polystyrene used for the Dadant and Betterbee hives is significantly higher (I forget the number) but is still very very low compared to what is used in the walls of a house in the northern part of North America. Bees just do not need much insulation as long as they have wind protection.
Lloyd Spear, Owner of Ross Rounds, Inc. Manufacturers of round section comb equipment, Sundance Pollen Traps, and full color custom Honey labels