Note:
Most of you in the US don’t need insulation. There I said it. You could use poly hives successfully if you wanted to with no major issues. Most poly hive users outside North America don’t use upper entrances. Keep using your wooden hives if it works for you.

That being said the porch works well in very cold climates (beekeeping is local) where there is just one entrance that needs to be protected at all costs. Remember we get no cleansing flights until March or April... the snow that fell late September is still on the ground, it just keeps pilling up,  my noon shadow is 50ft long, so no solar heating. I got the idea from Finland.......they’ll stay on until the 1st true warm spell.

Not sure what proof folks want on lower entrance air movement in a dead quiet hive (no fanning taking place). IR images clearly show heat. My lower entrance vs outside (delta T) shows a very nice linear relationship (some variability however values are well contained within a range). The stack effect heat loss/ventilation calc references that Alexander shared a few days ago apply here also.

             ***********************************************
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