Well, I was somewhat worried this spring since I could see zero activity outside my five hives, today I checked the largest one I have since the weather is nice and the entire hive is dead, all my hives died, the two smallest hives seem to have starved, not unexpected since they were very late additions. I can't figure out the big hives though, they didn't even use their food stores must be more then 60lb's of honey left, seems like they died early in the winter. They are in an area that gets a lot of wind, and I didn't wrap them in anything, the wood is 7/8" thick and only one hole 7/8"d was open I closed all the top bars on the top and let them seal it up tight, could anyone shed some light on this matter for me?
b. walden,
From what I understand, that is one of the shortcomings with TBH's, they are all horizontal and not vertical. Their normal configuration makes it more difficult to winter the bees in colder climates.
I agree that cluster size - and therefore their control over temperature - is important. This goes alongside emphasizing the need to keep strong colonies, and to provide adequate insulation so they have max control over their environment.
I ran one TBH, my first hive, in Wisconsin in 2008. It survived the winter. I used a Michael Bush type design where the bars are the roof, and then for good measure I put a one inch styrofoam lid which was encased in scrap plywood on top of that.
It only had one entrance, a top one, which was just the first bar held back 3/8 inch. The lid overlapped it by an inch to keep the rain out. I reduced this entrance from full width to about 2 inches by putting in little blocks of wood.
The hive entered the winter with comb and honey on all bars almost all the way to the back of it's 4 feet length. The bars were 16 inches long.
The hive was located on a south facing slope with woods north of it. Additionally the bee population was large. The queen was a MH offspring, the original MH queen swarmed in June.
Clearly I was lucky, this is only observational data, but I post it to illustrate that a TBH can survive in bitterly cold northern climes. Don't give up.
Adrian.
I didn't feed them but they might have found some other source of food, I have read about several people that have a lot of success with this hive design, its only called Kenyan top bar hive because it was made popular relatively recently and only for the sloped sides, its a very old design though, also bees themselves are not native to north America. I'm sure the tbh is usable in winter climates, the presence of uncaped honey and honey on the floor would create a larger humidity issue, humidity becomes condensation, then becomes ice, this could prevent the bees from moving to honey or just chill the colony faster then they could heat.
Sorry to hear about what happened, Sam. I had a similar horror - but thankfully not as bad.
I started with two nucs last spring and the colonies grew well, considering the awful wet weather here in NY State. I didn't take a drop of honey figuring they'd need it for the winter. I had one of Sam Comfort's 36 inch hives and another like Phil Chandlers 48 inch with a screened bottom and wood floor. I sealed up this hive too tight and when I opened it, at least half the colony lay dead on the floor. Lots of black and green mold all over the place - even on the outer combs. It was terrible but at least I have some bees. It's back to the size of a nuc colony so it's beginning all over. Sam Comfort's very rustic design with a solid floor did much better. Not as many dead bees and I think this colony will bounce back faster.
I think I'm going to drill a couple of 1 inch holes on the top of each side to allow for convection flow, to cut down on the condensation that surely killed them.
I have a hive that is Phil Chandler's design too, and my bees died. You have to remember that warm air rises, so if you drill those holes on both side, the warmth could completely ESCAPE from your hive in the winter. I asked Michael Bush who posts here a similar question, and he told me to drill them on the top on ONE side only. You don't what to create a wind tunnel in there.
I've decided (without any real experience or data) that dry is more important than warm for the bees in winter (conduction v convection), so I'm creating a vented attic space over the bees. I'm going to set it up so that air gets drawn up through the hive and out the roof all summer, then I'll add absorbent insulation in the fall (newspaper) below the attic vents so that the newspaper will dry to the attic side and keep the bees dry.
I live in the PNW, it rains rains rains a lot here in Seattle. So the damp can really do the bees in. Your local climate conditions are nearly everything.
Here is what David Neel a local beekeeper who runs Island Apiaries said to me in email:
"While in an average humidity environment that [a quilt box] works great, here the big bee killer is the higher than average humidity we have. The average winter temp we have here is 42 degrees F. While it does drop lower than that, it is for relatively short periods. I feel that efforts to keep heat in here are largely pointless exercises, from the bees point of view, we don't have a real winter. the bees that do well here- Carniolians, Russians, Buckfasts,etc all originate from areas that have a MUCH colder winter. any effort to keep heat in for them is pointless here and even in the best of circumstances will trap humidity. I am a BIG proponent of screened bottom boards and for the majority of the year, I leave them open ( I will frequently throw away the slide in board that comes with commercial units). A strong winter cluster will maintain a 93-98 degree temp in the center even in the worst of winters here and the bees can stand exposure to 20-30's with no ill effects for several hours. with the way they cycle through to the center of the cluster to warm up, they really never are exposed to low temps for that long.
I use a laser thermometer to check the temp from the outside of the hive regularly and if a hive is failing, I will use a probe thermometer to check the actual cluster itself. if they seem to be too small to keep temps up, I will slide a perforated plastic board under the hive to help them out. I mark these hives and check humidity every other day to make sure it is not climbing too fast and remove and replace the insert to counter increases.
Since I started doing this, my winter losses have dropped to a small fraction of what they were before.
feel that much of the winter losses in our area are due to humidity and not nosema, mites or CCD. The fact that we have a fairly unusual micro climate here in the PNW is not covered in any books, so the average beekeeper does what they read in books that are aimed at the rest of the country and then wonders why their hives are having troubles.
I feel that beekeeping needs to be approached regionally and most of your advise needs to come from other beekeepers who have kept bees successfully in your area."
Abha,
Yes, convection is indeed an interesting phenomenon. As a science teacher, it's difficult for me to dispel the myth to my students that hot air rises. It does NOT. Cold (read "lower temperature") air is denser and heavier, fills up an area (on the bottom of a room, for example) and actually PUSHES up (and out if there is a window) the lighter, less dense warm air, as it takes up space. The illusion is that warm air rises. Anyone who wants to get rid of the odors of cooking opens up the bottoms and tops of the windows for this reason - although they are unaware of the science of it.
In addition, it is the warm air that is more able to hold moisture - cold air has less of a capacity to do so. For condensation to occur, air must cool to the dew point. Witness, condensation on the outside of an iced glass on a summer day: The dew point is being reached on the surface of the glass where warm, moist air hits cold surface.
All this may help us understand how to best care for the girls during the winter. I don't want to set up a "wind tunnel", but there must be a way to allow this warm moist air to escape in the most efficient way. Perhaps Michael Bush's idea of holes at the top of ONE side may be a good idea.
Excellent, I was trying to imagine what airflow would look like inside the hives, Thanks!
What I did was drill a 7/8" hole every 6" along the bottom of my 48" tbh then screened them on the inside, I also moved the entrance to the top of one side on the wall, 4x 7/8" holes spaced 8cm apart, this should give me a small amount of upper venting. The reason for 7/8" is that standard wine corks fit perfectly, so for a smaller colony I would plug some holes.
I was thinking about drafts inside the hives and wondering how the bees managed them, since I have seen them nest in attics barns ect, the comb is a very good air baffle 1/2" from all the walls running across the space inside the tbh, this plus the bees themselves pack the spaces between about 1/2" seems like a very effective air management system. It also explains (at least to me) why one 7/8" hole wasn't enough ventilation :doh: I think they can manage some exposure but humidity drastically reduces the ability to stay warm, not to mention running out of oxygen, the circulation profile of a tbh is different then a lang, the lang would be a bit like a chimney so a small entrance at the top and bottom might be enough... Mind you this is all speculation.
If warm air at the top of the hive meets the cold air from outside the top of the hive, it will cause condensation over the cluster, right? I put a bale of hay on top of my hive to prevent this in my one and only first year tbh. They made it, whew. I put bales on each side, not the front or back, for wind breaks, they were not tight against it. Its windy here too, so the bale of hay on top gave me assurance it wouldn't be blown over. Wouldn't a bale of hay on top mimic the top if a tree, (cellulose) for insulation and prevent condensation, and same for a quilt box in a warre. Perhaps tbhs in northern climates should incorporate an insulated roof, or top. I do not have a screened bb.
Good luck,
Carrie
It only rises in the presence of cooler air, if all air was hot it wouldn't rise.. It's the difference in mass that causes one to displace the other.. I love science.
So do I, Sam. And you are right; that's what I tried to explain previously. But I'll speculate that there is always lower temperature air present in an area - unless one is in a vacuum. You can test this idea in any area with several thermometers.
But back to the bees: I think what may be happening in the hive is that when the lower temperature air meets the heated air near the cluster, the dew point is reached. Unless this warmer, saturated air has an escape route, moisture condenses on the bees on the outside of the cluster, lowering their temperatures. They remain constantly wet, cool air continually hits them and they slowly succumb, drop off and die, and the cluster size gradually diminishes. I know the bees on the outside of the cluster are constantly rotating to the inside but I figure this has got to take a toll on them over the months - especially during cold snaps. Then the dampness creates a mold situation in the hive that makes matters worse.
I'm very new to beekeeping and I'm sure others probably have ideas of what may be going on. I'd love to hear them.
I think the mold is only a problem when the weather starts to warm up (at least in the north) I remember seeing ice inside the hive during the winter I just don't know how much there was, our winters get very dry the bees and maby some uncapped honey are the main moisture producers imho, same net result though. Thats why I moved my entrances to the top, I also spaced them further apart, they were 6cm apart before now they are 8cm, that plus the vents in the floor should provide good ventilation without to much draft. "crosses fingers" I'm not sure what else I can actually do with my hives without totally redesigning them.
If you place a sheet of glass or plastic over a colony in winter, the part immediately above the bees gets warm. I don't care if it because warm air rises (and I still think it does) or because it was pushed: the fact remains that bees emit heat that finds itself somehow above the cluster.
Now if that air contains a deal of moisture - which it should - and then it hits a cold surface, like an un-insulated roof, it will release that moisture in the form of condensation, which - because the cold surface is now warmer because of the (rising) heat, will mostly form around the edges and the adjacent vertical sides, and then drip back down into the hive, in time enabling mo(u)ld to form in areas unheated by bees.
If, instead of a thin roof, you have a thick layer of vapour-permeable insulation, such as straw or wood shavings, the water-laden air will filter out through the insulation and cause no harm. This mimics pretty well what happens naturally in a hollow tree, which also has the benefit of absorbent walls.
If you also have adequate, floor-level ventilation, the hive will stay dry and the bees will be able to maintain their cluster temperature.
No way water is forming under the tin and dripping on the top bars.
Mould wont form in sub zero temps, thats why in my location the bees only have a mould problem once they come through the winter..
I'm hoping (because many people have tried it) that more bottom venting will work.
Interesting fact about the outer bees rotating with the core ones for warmth, didn't know that Stone.
Might be worth putting something between the bars and the metalwork, as that stuff will get hot in the sun. You don't want a melt-down and more than a chill.
Regarding the mold: When I opened my hives last weekend for the first time after our winter here, there was A LOT of mold as I had described previously. It was very disturbing. Could be the temperatures never got down low enough in the hive to inhibit mold growth. Or it could be that mold does okay in cold temps. I don't know how low temps have to get to stop mold from growing but I do know that forgotten bread and cheese in the back of my refrigerator has no problem growing it!
Lol, did your bees survive? Idk never thought about mould growing in cold temps, we get pretty low here -30c in extreme cases.
The tin isn't next to the wood so air can move between, the top bars never heat up.
Yes, they survived - but barely. I lost half the bees in the colony, at least. As I think about it more now, if all the bees had survived the poor ventilation, many might have starved instead. Even though I took no honey from them, I noticed they hardly had any left from their stores.
I'm learning a very great deal from the postings on this forum. I'm thinking about how to best ventilate my hives in the future.
I just checked and my TBH failed. Since they started as a late swarm, I'm guessing that they didn't build up enough. Since they left plenty of syrup behind so I also suspect they didn't have enough comb to create sufficient stores.
I also lost one of my lang hives from a split. This surprised me because they looked the strongest out of 5 and had survived up until about 3 weeks ago. Maybe they were actually about finished then. I can't even guess why and doubt I'll ever figure it out.
Heartbreaking isn't it? I was almost as sad as when I had to put down my dog. Which is strange because they are just bugs. Not knowing for sure what got them is kinda annoying too.
I'm thinking about adding a 1/8 notch to the length of each bar so the the bars can ventilate up through the attic, but I'm having trouble figuring out how to vent the attic. Putting extra hole through the roof doesn't seem like a good idea.
My ventilation idea is to duplicate what I do in my own kitchen. Using the principle of a simple convection cell, I just open up the top and bottom of the windows a little. Cooler, denser, heavier air comes in, hits the floor and pushes the warmer, lighter air up and out the top window. Takes out warm odor filled air in no time! I do the same thing upstairs in the bedrooms when the wood stove in the living room back puffs and sends out a bunch of smoke upstairs.
I figure I'll drill a few 1/2" holes on the long side up near the top bars. The cooler air will enter through the bottom hole entrances (on the same side), get warmed by the cluster, then cycle around and out the top holes. No wind tunnel effect - just remove the warm moist air to hopefully provide a gentle, effective ventilation. I reckon you can think of these holes on top as a chimney of sorts.
I've used cork-sized hole ventilation toward the top of my hives, and the hives we sell actually have 3 such holes and I find that the bees propolize and unpropolize as they desire.
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