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Author Topic: 0c 32f outside 18c inside at floor should i be worried?  (Read 17019 times)

Offline derekm

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0c 32f outside 18c inside at floor should i be worried?
« on: October 24, 2011, 07:02:22 pm »
My bees are in my new hive, the night time temps are zero c but the floor level temp is 18c, the top  of the hive temp is 34c at 7am. The colony is only a moderate size,they are accumulating stores from the ivy and gorse, when the temp gets up to 9c there is quite a bit of activity even though the hive is shaded. is this a problem ?
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #1 on: October 24, 2011, 07:13:22 pm »
You’re in uncharted waters my friend!  Who knows!  That’s the fun in experimenting.

My biggest concern would be to make sure you don’t have any wax moths in there with the bees; especially if you’ve got a small colony and it is that warm. 

It would be interesting to weight this hive from time to time to track its food consumption vs time vs temperature.  It will also be interesting to see how long they keep brooding.

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #2 on: October 25, 2011, 02:30:33 pm »
Have you checked for eggs lately in your super PU hive?  Are you doing any kind of feeding?

Since the temperature in your hive is above the cluster temp, I would guess the only significant energy the bees are generating is to keep the brood warm.  If you have a smaller colony, there might not be much brood this time of year.  That would require just a small patch of heater bees to keep warm and hence the wattage output from the bees might be on the low side?

How do you decide when to open ventilation (top?) to prevent overheating?  Or are you leaving that completely up to the bees (via evaporating water)?  I use adjustable top vents in my super PS nucs for that purpose and basically guess how much ventilation to give them.  It's a guess based on how active the bees are vs the outside temps.  

Have you back calculated how many watts the bees are making based upon the temps you are reading?

Offline derekm

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #3 on: October 25, 2011, 03:57:44 pm »
Doing anti varoa treatment at the moment so expecting a hiatus,  but we saw larvae, this weekend didnt look especially hard for eggs. lots of sealed brood...
Deciding to do top ventilation based on floor temp. if it goes above 21c , ventilate. Dont seem to get bearding, or much fanning. remember they have a slotted floor and a fairly large entrance 30 sq cm.
No feeding in the original PU as they are packing plenty way.

Only have two temp probes in this hive it was put into operation rather quickly, as usual.

Dumped the last of the wooden parts in the first hive. They are now on PU roof ecke and super  with bought Polystyrene brood box. Seemed to get a fairly rapid increase activity. Taken a month to gradually make the conversion.
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline windfall

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #4 on: October 27, 2011, 06:12:34 pm »
I don't have any temp probes in the insulated nucs I built this fall...that would be nice info to have.

But I have been peering into the entrance tunnels (bottom) for the last 2 days to see what I could see.

These are 5 frame nucs, very similar to Bluebees, 2" polystyrene.

Yesterday was 45F and in each I could see 2-3 bees fanning inside the hive a few inches back from the entrance
Today's max was 36F, in the stronger of the 2, again a few bees fanning.

I decided they are holding too much heat and opened the top entrance to 1/4" X5/16". Depending what I see tomorrow I may well do the other as well.

I also observed a "drinking" like behavior that I have posted separately on in the general forum, as I really am not sure what that was about.

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #5 on: October 28, 2011, 02:02:20 am »
OK, I checked my foam works tonight; about 12 midnight.  It’s literally freezing out there!  Frost on the pumpkins AND hives.  31F / -0.5C.

Here’s what I found.  Bees guarding the entrance to every single hive and nuc!  Good girls, don’t let any frozen wax moths in :-D  They came out challenging me when I got my IR temp sensor too close.  The air temp reading at the entrances were 55 to 65F / 18C. 

Popped the top of one of my 1.5” (3.8cm) foam nucs (the PV=nRT nuc) and found the temp to be 64F (17.7C) inside as shown in the photo below.  This nuc has about 5 frames worth of bees in it right now.  Had fresh eggs as of Oct2nd.  Haven’t looked for brood lately since we’ve had cold cloudy weather.



Here’s a midnight photo of one of my Dadant like full sized hives with a top entrance.  Wintering in a single box here.  Note the frost on the top of the hive and bees at the entrance! 



Hives look to be about 30F warmer than the outside temp due to all the insulation, even with a top entrance in the full sized hives.  The bees are not clustered yet.  Probably won’t happen until it dips down to the low 20s or teens here.

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #6 on: October 28, 2011, 03:38:11 am »
Windfall, I found my bees fanning last night at the door when it was 31F outside.  However it was only 64F inside, so I don’t know why exactly they were fanning.  Maybe they saw my flash light and that triggered them to scent the entrance?  I don’t know.  I do know it wasn’t too hot in the hive.

Unless you’ve got a lot more bees and brood in your foam nucs than I do, I can’t imagine they’re really overheating in Vermont at this time of year.  My hives are running about 30F above the outside temp and unless it gets into the mid 60s here again (unlikely), I’m not going to open my top vent any further. 

I’ve got the top vents in my nucs open to about 12mm x 3mm + any imperfections in my construction.  Really a pretty small vent.  I just want it big enough vent to water vapor + CO2 and draw in needed fresh O2.  Too big and you start defeating the benefits of the insulation. 

Sounds like you’ve opened a top vent with an area of 48 sq mm.  That is close to what I am using.  Your bees might still be raising fall brood (based on the report of them sucking up water) and hence I would be cautious about cooling them off too much.

Offline windfall

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #7 on: October 28, 2011, 09:12:10 am »
Thanks for the feedback bluebee,

My thinking was not so much that they were overheating but that they should be in cluster. I assume if they stay too active they are going to burn through their stores quite a bit faster?
I was also wondering if the fanning might be about trying to reduce interior humidity? Although it really didn't seem very wet from what i could see...at least not compared to reports of dripping hives I have read.

This nuc was PACKED when I transferred them a few weeks ago, the other was less so and I left it closed up on top. I was thinking of leaving the stronger one open on top as is untill the cold really settles in and then closing it back up.

I know Robo keeps the winter nucs without venting but those are the 1"foam....

Probably I should just leave them the heck alone, but I get so darn curious.

Where did you get that little IR probe? And what did it cost?

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #8 on: October 28, 2011, 01:22:15 pm »
Windfall, I got the IR thermometer at Harbor Freight a couple years ago.  It was about $20 at the time.

We need to put one of our hives on some scales to get data on winter consumption at warmer temps.  If the bees aren’t generating heat to stay warm, are they really going to be burning through the stores?  I doubt it, that’s not what I have seen.  Making heat is what takes a lot of energy.  Discounting brood consumption, Stores consumed = Energy generated in the hive.  Insulated hives require less watts.  If the hives are above clustering temps and the bees are not rearing brood, they really aren’t making much heat.

Just as an aside; the main reason I’m using a screened top on my foam nucs is so I can observe how to bees are responding over winter in these super insulated hives.  It sounds like you, I, and Derek are the only ones on this forum admitting to using super insulated homemade foam nucs so there may not be a lot of hard data for us.  The screens can be a good way to collect hard data regarding their behavior.  

You can also gauge hive strength with a top screen and you can feed all winter with a top screen if you want.  If anybody else makes any of these super insulated hives, you might want to consider using a top screen on some of them.

Offline derekm

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #9 on: October 28, 2011, 04:08:57 pm »
Thanks for the feedback bluebee,

My thinking was not so much that they were overheating but that they should be in cluster. I assume if they stay too active they are going to burn through their stores quite a bit faster?
I was also wondering if the fanning might be about trying to reduce interior humidity? Although it really didn't seem very wet from what i could see...at least not compared to reports of dripping hives I have read.

This nuc was PACKED when I transferred them a few weeks ago, the other was less so and I left it closed up on top. I was thinking of leaving the stronger one open on top as is untill the cold really settles in and then closing it back up.

I know Robo keeps the winter nucs without venting but those are the 1"foam....

Probably I should just leave them the heck alone, but I get so darn curious.

Where did you get that little IR probe? And what did it cost?

Research was done with clusters to see how much food was consumed with temperature... This research was done with different sized clusters to see exactly what happened, ans why and when bees clustered.  Food requirements decrease with increases in temperature. The research was published in 1958!
OBSERVATIONS ON THE TEMPERATURE REGULATION
AND FOOD CONSUMPTION OF HONEYBEES
(APIS MELLIFERA)
BY J. B. FREE AND YVETTE SPENCER-BOOTH
Bee Research Department, Rothamsted Experimental Station.
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline windfall

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #10 on: October 28, 2011, 04:15:01 pm »
Bluebee, your point regarding needing less heat (fuel) overall due to heat conservation is well taken. What I don't know is how Bee physiology is affected by temp.

For some creatures that are able to run their bodies at different internal temperatures simply being warmer puts them into a higher metabolic state, and they will burn more calories. Not to generate heat, but simply because their physiology requires it at that temperature. Basically the warmer they are, the higher their idle runs. I don't know if this is true for bees, or if their calorie consumption is purely dictated by physical activity like flying or "shivering".

My goal (I think) is to find a balance of insulation and ventilation that keeps the bees from working hard to stay warm enough to survive but does allow them to spend most of the winter in cluster at "low idle".

If they are so warm that they are fully active inside the hive, don't we just imitate a 6-7 month warm weather dearth? Well that may be a poor comparison since they are not flying but hopefully you get the point I am trying to make.

Derek, your post went up just as I was finishing this. It does not surprise me that food consumption went down with increase in temperture when in cluster. Does this research show that to remain the case once the bees are warm enough to break cluster? That is the crucial point to know it would seem.

Offline derekm

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #11 on: October 28, 2011, 04:40:30 pm »
this paper shows that clustering is also a group  behaviour thing not just temperature related. However the food consumption does go down all the way with temp going up to the roof.
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #12 on: October 28, 2011, 04:43:53 pm »
I agree with your points Windfall.  My plan for this winter is for my bees to run at low idle too.  I DO want them to cluster on cold nights.  My foam design is good for about +30F temperature gain inside the hive.  As with Vermont, it gets a lot colder than 20F here in the winter.  So when it dips below 20F, the temps in the hives should be in the 50s and the bees will cluster.

Derekm is doing some extreme beekeeping!  It will be interesting to watch over winter.  Will the bees over rev and float their valves or will they leave us in the dust?  Time will tell.   

Derekm, I’ll have to see if I can google that paper, thanks for the reference.  We can also verify or deny that ourselves if we can set up a system to track our hive weights vs temperature vs time.  For a fuller data set we could add electric heat to get data at more points. 

Offline derekm

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #13 on: October 28, 2011, 04:51:22 pm »
maybe I sholud have asked Prof Tom Seeley this  question (who I met yesterday here in the U.K a very interesting chap)
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #14 on: October 28, 2011, 04:55:32 pm »
I bet the professor would be very interested in your super polyurethane hives.

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #15 on: October 28, 2011, 05:43:46 pm »
I just finished reading the paper you referenced.  Interesting data!  It seems to confirm what you have been saying, as the temps go up, the bees consume less stores.  Less stores are consumed all the up to 35C!!! 

Offline derekm

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #16 on: October 29, 2011, 03:32:00 am »
Windfall, I found my bees fanning last night at the door when it was 31F outside.  However it was only 64F inside, so I don’t know why exactly they were fanning.  Maybe they saw my flash light and that triggered them to scent the entrance?  I don’t know.  I do know it wasn’t too hot in the hive.

Unless you’ve got a lot more bees and brood in your foam nucs than I do, I can’t imagine they’re really overheating in Vermont at this time of year.  My hives are running about 30F above the outside temp and unless it gets into the mid 60s here again (unlikely), I’m not going to open my top vent any further.  

I’ve got the top vents in my nucs open to about 12mm x 3mm + any imperfections in my construction.  Really a pretty small vent.  I just want it big enough vent to water vapor + CO2 and draw in needed fresh O2.  Too big and you start defeating the benefits of the insulation.  

Sounds like you’ve opened a top vent with an area of 48 sq mm.  That is close to what I am using.  Your bees might still be raising fall brood (based on the report of them sucking up water) and hence I would be cautious about cooling them off too much.

the magic 18c temp again ... if they can, it appears they will regulate peripheral areas to 18c..(my bees do exactly this). thats the temp of the outside of swarm clusters(i will dig out the paper). my guess (guess only) is a box with the floor area at 18c is in good shape. 18c is not a random number. but they are fanning , try increasing the lower entrance size rather than top venting. a larger bottom entrance gives the bees more control. I would only use/increase top vent if the entrance has to wider than 30 sq cm to hold 18c at the floor.
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #17 on: October 29, 2011, 08:53:42 am »
Despite the 1958 study, I would be willing to bet that energy levels and food consumption goes up if the bees starts buzzing and fanning in the warm top layer of a foam hive.  I’ve noticed this happening in my double decker foam hives (5D+5M) but not my single story 8D nucs.  I think the tall foam hives are promoting more temperature stratification and maybe it is getting too warm at top.  A lot of bees tend to congregate at the top of the hives and I was reading 79F / 26C up there with my IR thermometer yesterday when it was 45F / 7C outside.  My casual observation is the bees are usually much calmer when the temp in the hive is around your magical 18C number.  I can easily observe what they are doing since I am using screened inner covers.

Offline derekm

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #18 on: October 29, 2011, 03:00:54 pm »
found the paper


THE MECHANISMS AND ENERGETICS OF
HONEYBEE SWARM TEMPERATURE REGULATION
BY BERND HEINRICH
Department of Zoology, University of Vermont, Burlington, VT 05405.

it appears that the 18c is bees on standby temp,  hanging around the lobby waiting for something to happen temp...
Again it seems chilled out for a bee is 18C ...
If they increased energy bill for your home by a factor of 4.5 would you consider that cruel? If so why are you doing that to your bees?

Offline BlueBee

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Re: 0c 32f outside 18c inside at floor should i be worried?
« Reply #19 on: October 29, 2011, 03:17:36 pm »
Derekm, you noted earlier in this thread that you treated your hives for varroa.  Was that just a precaution or did you have a high mite count?

What did you use for treatment?  Did you consider heating the bees up to kill the mites?  With a super insulated hive, this seems like an ideal way to treat for mites in the winter when the bees are broodless (assuming it works that is)

I’ve read a few posts on the bee forums now that heating broodless bees (mites on the bees) to about 46C for 10 minutes has been found to kill most if not all the adult mites.  What do you think?  A good experiment for your super PU hive?

 

anything