Question: Some people say a top entrance lets the heat out. How do you do your entrances?
Answer: In any hive (top bar or otherwise) I think a top entrance in the winter is always a good plan. It lets out the moisture and cuts down on condensation. Heat is seldom the problem, condensation is the problem in winter. A top entrance will let it out. Mine are all JUST top entrances. The reason I went with them was the skunks. My first TBH have a bottom entrance and the skunks were a serious problem. After going to the top entrances they have ceased being a problem. My entrances are simply the gap at the front of the hive between the first bar and the front wall. No holes to drill.
Question: Can I put a screened bottom board on my TBH?
Answer: You can. But I wouldn't leave the whole thing open as this will be too much ventilation.
Question: How can you have too much ventilation? Isn't ventilation a good thing?
Answer: Of course in the winter, too much ventilation means too much heat loss. But even in the summer the bees are cooling the hive by evaporation, so on a hot day the inside of the hive may be cooler than the outside air. So too much ventilation could result in the bees being unable to maintain a cooler temperature inside. When wax heats up past the normal operating temperatures of a hive (> 93 F) it gets very weak and combs can collapse.
Question: On Langstroth hives you often have a top and bottom vent to get sufficient ventilation. Should I provide cross ventilation in my TBH?
Answer: Bees seem to have more trouble ventilating a vertical hive with no vent at the top. They have to force dry air (which wants to go down) up to the top and hot moist air at the top (which wants to go up), back down and out the bottom. It's sort of like walking 20 miles to school, uphill both ways. So a top vent or top entrance in a vertical hive seems to be very helpful as it allows the hot moist air out the top which sucks the dry air in the bottom. With a horizontal hive, this is not an issue. They just move the air in a circular fashion in one side and back out the other side and out the door. Sort of like a nice level walk with no hills. This seems to work well. With cross ventilation (such as a front and back vent or entrance) the wind may blow through the hive and that may be a bad thing
If you enter top bar hives into google you will find plenty of plans especially if you try google images. I hope that helps, regards Jim
