Thought i would just do an experiment to check on heat loss via a mesh floor, compared to solid. Athough only with bulbs,i intend to do another with full colonys,will be interesting to see the variation in this as well,and to see how much warm air gets sucked out the bottom by the wind.
Two new,near identical cedar hives,roofs with no vents,crown boards with open feed hole,brood boxs,frames,some empty, some full but equal,and one with a solid floor,one with open mesh.
Two hives are stood side by side on a 10" stand,with a pair of accurate matched thermometers, placed in the same position on top of each crown board,and a large fan placed a few ft in front,and central to both hives to simulate a light wind.
Inside in the center of each hive is a 150 watt bulb to act as heat source.
After 1 hour with fan facing entrance on hive with mesh floor the temp is 17c
After 1 hour with fan facing entrance on hive with solid floor the temp is 29c
Another hour but with hives turned so wind direction would be from rear,
open mesh 17c
solid.. 26c