What REALLY works regarding ventilation?!?

[Hoss]

OK..I know Michael Bush's tagline is that it all works if you let it...but is there a consensus regarding screened bottom boards vs slatted bottoms vs solid bottoms?  How about ventilation of a vertical (lang-type) hive? a TBH?  Reading various forums, you quickly realize that opinions vary (greatly, sometimes) with regard to ventilation and its effect on mites.  I belong to a beekeeping association but the looks I get when I talk about foundationless frames or top bar hives tell me these folks are indoctrinated pretty hard into the old way of doing things.  So before I spend a lot of time and some money, I thought I'd run these thoughts by ya'll for comment and suggestion.

First off, I started keeping bees last year in 3 top bar hives modeled roughly after the Bush design.  In the heat of the Georgia summer, I had more bees on the outside of the hive than in.  I lost two hives between then and now (one to a bad queen and one to starvation, my bad).  Since the hives are vacant, I thought I might look into modifying them before I reinstall new packages.  My thought was to simply cut out some openings in the bottom and screen over them and fashion a hinged lid to close when necessary.

Secondly, this year, I want to try a Birkey Condo hive using a double wide deep and center the supers over the brood area.  Since I'm already building a double wide hive body; I'm going to have to build the hive bottom, too.  My thoughts are to build a solid bottom board with slats running parallel with the frames and also build a DE-type ventilated "inner cover" using the Honey Run Apiaries free plan for the super.

So...straighten me out if I need it or tweak my thoughts.  I'd like to take advantage of the vast amount of knowledge that is banked here as I already graduated from the School of Hard Knocks with a Masters degree for my "real" job.  Thanks, Hoss

[ArmucheeBee]

Hoss

I'm a few miles away from you in Rome.  I built a KTB hive last year and put in a screened bottom.  Did not get to use it due to how late I built it, but plan on getting a swarm in there this year.  It's like a mini-oven so I went with the screen for 3/4 of the length.  The 1/4 has a wood floor where I can put a chick feeder with syrup.  I also drilled 1 in. dia. holes in the sides not ends.  I like holes because I can take a 1 in. dowel rod cut as long as a wine cork, shave off the ends and plug.  I can keep most of them plugged until the hive grows to numbers that allow me to unplug them.  I'll put pics on when I get home.  Where do you get your bees?

[Hoss]

Great...I take it you haven't kept any bees in the hive, though?  As for mine, this year I'm getting 3 packages of Italians from a local sideliner.  Last year, it was Russians from Lula and I may get another couple from there again this year.  Will depend on how many hives I can convince the wife it takes to pollinate her garden this year...
A side note...how many posts before I am permitted to add image links?

[Natalie]

Hi and Welcome.
Ask Robo if he can post the links for you, you send them to him and he will put them up or maybe he will allow you to.

[ArmucheeBee]

Not sure about the number of posts to put pictures on.  I'm going up next Sunday to Lula to get 2 packages.  Here are my pics. 



This is the bottom with screen and wood floor just big enough for a feeder.

[Michael Bush]

In a top bar hive I've had good luck just not worrying  too much about it, but then I have a top entrance to let the moist air out in the winter.  They seem to do fine without anything else.  On a vertical I try to have at least a little bottom and a little top ventilation.  After that the bees do the rest.

[Hoss]

On a vertical I try to have at least a little bottom and a little top ventilation.  After that the bees do the rest.

Would you consider the opening size to be sufficient at the bottom or would screening some portion of the area be required?

[Michael Bush]

On my top bar hives I have NO bottom ventilation and only top.  They seem to have an easier time ventilating a horizontal hive.  I suppose they don't have to move that hot moist air at the top all the way to the bottom.  It's easier to move it along the same plane.  Horizontal hives seem to have less ventilation problems.

[Brian D. Bray]

For your consideration:

I have bottomless hives set on slatted racks.  I use reversable bottom boards turned upside down with the small entrance installed as a top entrance/vent.  I have successfully overwintered both hives without once using the mite board to close up the bottom.  Temps were down into the single digits for everal days at a time and the bottoms were completely open.
I checked them today and they are making nectar, pollen, and brood as one would expect as this time of year.  My equipment is 8 frame medium boxes and I use a 3 box basic hive.
It worked well with Russian or OWC bees as they winter with a smaller cluster, use less of the stores during the colder part of the winter and still have sufficent stores to ramp up brood production in early spring.  Right now they have 8 frames of honey stores and are gradually buuilding up.
I experiecne zero bearding with temps into the 90's, the bees will, however, festoon off the slatted racks a few inches below the hive.
All debre (wax cappings, mites, etc) fall directly to the groud where the ants take care of it.  Since I've go bottomless in my hives I have not had an ant problem, probably because every thing gets dumped on the ground for then and there is no motive for the ants to climb up into the hive.

I am getting a package of Coradva Italian bees this spring to run a comparrison on overwintering in bottemless hives using a warmer weather bee versas the Russian and OWC.

The bees fan air in only one direction, up, when cooling the hive as the top vent allows this and the slatted racks provide a platform from which they can fan.  In most hives with out any top ventilation, the bees have to force air in both directions at once, up between the frames on one side of the hive and down between them on the other.  If you watch bees washboarding you'll see that they will sometimes change their angle or body attitude to help direct the air where it is needed.  You'll often see bees on the opposite side of the landing board facing the opposite direction and doing the same thing.  Air up, air down.

[Hoss]

Appreciate the responses...I'll be trying various methods as I build up my hive count this year.  My top bars utilize a telescoping type cover, so I am going to modify a top bar to provide a second entrance as well as a port to ventilate and see if it provides any relief for the bees during our summer temp runup.  I'll post pics when I have permission

[trapperbob]

 It has been my experiance that bees do fine with the bottoms screened or open so long as you keep the wind from blowing up through the bottom. With langs you can set the hives on blocks set up in a box configuration this is what I have done and they seem to make it through winter just fine and it gets into the zeros here. With the TBHS I like to block off the rear of the hive and leave the screen open at the front for several inches. It seems to me the most important part is to be very sure they have plenty of winter stores and they can survive almost anything. So long as there is enough food avalible they have enough energy to generate the heat they need to survive. That being said I have TBHS that have solid bottoms to. They seem to do well to but I leave a space in back open to vent the moisture. I'm not sure if it really makes any difference at all but it makes me feel better.

[Brian D. Bray]

It has been my experiance that bees do fine with the bottoms screened or open so long as you keep the wind from blowing up through the bottom. With langs you can set the hives on blocks set up in a box configuration this is what I have done and they seem to make it through winter just fine and it gets into the zeros here. With the TBHS I like to block off the rear of the hive and leave the screen open at the front for several inches. It seems to me the most important part is to be very sure they have plenty of winter stores and they can survive almost anything. So long as there is enough food avalible they have enough energy to generate the heat they need to survive. That being said I have TBHS that have solid bottoms to. They seem to do well to but I leave a space in back open to vent the moisture. I'm not sure if it really makes any difference at all but it makes me feel better.

A slatted rack solves that problem.  It provides, not only a place for idle bees to hang out, a dead air space that acts like an insulator during cold winter.  I just overwintered two hive, both bottomless with slatted racks and not mite board in place (left them out on purpose).  The hives face south and most of the prevailing winds during the winter come  from the south (winds to the low 90 mph and temps to single digits).  If I had Screened or conventional bottoms the hives would get chilled big time.  But being bottomless with slatted racks they didn't scoop up the wind and came through in great shape.