I have 3 holes in the center of my TBH...I had to use center because it sits between 2 Langs hives and I wanted the entrances spaced as much as I could. How do you ventillate an TBH. I have a huge beard of bees at the entrance in the afternoon.
Does your TBH have a screened bottom? With a removable bottom board? If not, or in addition to, I will sometimes separate the top bars a bit to allow better ventilation.
I have to be careful of making it possible for wax moths and big red ants to get in....so not sure that would work for me. I think I'll try making an air space above the bars and see if that will help. I could try drilling a hole in one of the bars on the end and putting window screen over it. That would stop bugs and the bees could plug it if they didn't like it. Anyone try that?
I took an extra top bar...drilled a hole about 2" from each end and stapled window screen over it. I put it in one end of the hive. I then took a 1" x 4" and split it down the middle. I placed both on top of the top bars inside of the holes in the bar at the end. This raised the cover about an inch. I have noticed a big difference in the number of bees on the outside of the hive. Guess it worked and the holes are less than 1/2 inch so the bees can cover them if needed on cool nights.