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Insulation depth

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Getting some Kingspan(?) or similar insulation for wintering both the top of the hive, and potentially alongside the frames if a colony is small.

Any recommendations to the thickness - 25mm, 50mm - does it matter?
 

SER 

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As it nearly always is with insulation, I'd put in as much as I could fit.

Si.
 

Hebeegeebee 

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An inch would make a huge difference compared to a crown board. I guess a sheet of 25 mm could be doubled and a large sheet - if that's what you get - will do plenty hives.
 

barratt_sab 

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What difference would it make?

Dil
The oracle (wiki) suggests that wood conducts heat about 3 times better than expanded polystyrene.

So, replacing a wooden crown board with an equal thickness of EPS should (all other things being equal) reduce the heat loss by a factor of 3.

Replacing a wooden CB with, say, triple the thickness of EPS would reduce the heat loss by a factor of 9.
 

Adam 

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The oracle (wiki) suggests that wood conducts heat about 3 times better than expanded polystyrene.

So, replacing a wooden crown board with an equal thickness of EPS should (all other things being equal) reduce the heat loss by a factor of 3.

Replacing a wooden CB with, say, triple the thickness of EPS would reduce the heat loss by a factor of 9.
Depends if he has an open mesh floor. Additionally, if the increased temperature results in brood rearing, then stores will be consumed quicker, and it may be you need to add more stores (an extra super) if on a regular national brood.

I like my bees to be nice and cold in winter. They thrive better in spring, they use less stores. Warm bees means brood, and brood means starvation if insufficient stores are provided.

To the OP, what size brood chamber are you using, have you an OMF and what makes you think warmer is better?

Adam
 
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To the OP, what size brood chamber are you using, have you an OMF and what makes you think warmer is better?

Adam
Thanks for the replies. One will be a single National, and the other a brood and a half WBC. Both have OMF so I don't think ventilation should be an issue.

I'm expecting the National colony to be relatively small, but hopefully sufficient enough to survive all things being equal.

Fairly exposed surroundings, would be very worried about leaving them without extra insulation on top, even the double walled WBC.

Not over concerned with keeping them too snug, but want to give them as much assistance as I can to help maintain their temperature.
 

oliver90owner 

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In addition to Barrat_sab, we could carry out a very rough estimate on heat loss from a standard National broodbox over winter.

Lets say the cluster is in the top half of the box, so most conductive losses will be shared by the crownboard and the sides (about an equal area for each?) so lets be really rough here and assume energy loss is 50% through the crownboard (it will be far more than that as the side walls are 3 times thicker for the most part). Reducing the roof losses by a factor of ten will make them almost negligible. That will of course mean slightly more heat loss through the sides, but small enough to be negligible, too. No computer modelling here!

So we may have nearly halved the heat losses through the top half of the hive. Now let's be really assumptive here and say 50% of overall hive losses were through ventilation and the bottom of the hive. So now the savings are 25% or the bees' heating costs for the winter. Assume 10kg of sugar is ample for thermal energy requirement and we have an instant (very conservative) saving, on cost, of 2.5kg of sugar. That capital expenditure has a 100% pay-back in less than one winter (even at one pound fifty for a single sheet of insulation).

Now consider the advantages to the bees; less stores to consume for that energy balance, less build-up of materials of defaecation within the bees (so longer between cleansing flights), less likely to use all stores in one area and need to move across the hive to other stores (potentially a colony threatening activity if the need occurs during a very cold spell). Added to that earlier brooding is likely and as most stores (I would say in this scenario) are required for feeding the early brood, the colony is well placed for a good start in the Spring, with less chance of failure or reduced activity due to stores levels.

All in all, a 'win-win' situation for the minimal outlay for a single sheet of expanded polystyrene. Further to that, I think my workings give a very conservative value for energy savings associated with the energy losses from the crownboard.

Regards, RAB
 

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My experience is that when i have 30 mm wooden box compared to 20 mm polystyre box, simple wood consumes 50% more winterfood.

Spring build up is faster and the hive is earlier ready to forage surplus.

One kg honey is egual 8 kg sugar price. the most important in food consumpion is that there is no danger that food will be finish.

Very important in poly box is the weight. Langstroth box is 1 kg and the moist wooden box 8-10 kg.

I tried a mesh floor with 6 hives and it was a catastrophe in food consumption. Never try again.
 

peteinwilts 

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I put a thick piece of polystyrene above all of my colonys last year with a solid crown board and did wonder if there was actually a point (need to get my thermal probes out!)

I already use a polycarbonate roof around my 18mm softwood ply roof. If I use an 18mm softwood crownboard (or a solid board on top of the crown), I am not convinced if there is a point of putting polystyrene in the roof.

I experimented with having insulated sides last winter on a hive. This was the only hive I lost, which may have been a co-incidence, but maybe not....

My thoughts are strongly to follow Finmans lead if it is very cold like last winter, but normally our winters are just wet and cool and am sure keeping them dry and well ventilated is the most important thing...
 

peteinwilts 

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talk of the devil! serves me right for leaving my desk whilst typing a post!
 

Finman 

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[QUOTE=peteinwilts;81946Iu but normally our winters are just wet and cool and am sure keeping them dry and well ventilated is the most important thing...[/QUOTE


you thre in south cannot understand that the difference
in heat an relative moisture is the thing which keep the hive dry. One thing is a dew point, how it is situated.

When you have cold rainy weather, do you ventilate moisture out from your home. No, you rise the room temperature.
 

beebreeder 

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Insulation, don't bother, they don't have kingspan in trees!
I overwintered national nucs on 5 frames in 12mm ply boxes no trouble with snow and frost last winter.
 

MuswellMetro 

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well the U-value of the oak tree the feral bees living in my woods is a bit better than 12mm ply

the sides of the hive would be equivalent to 6" of solid oak and the roof depth is about 50ft

i take the veiw that older beeks sometime knew best, if you look at old films of the 30's when hives had sacking pillows or straw plaits above the crown board, good insulation but vapour porous

[ame]http://www.youtube.com/watch?v=902k2HzCO4E&NR=1[/ame]

So i insulate but have a gap by the wall to allow water vapour to escape, so the dew point in the roof is above the crown board
 
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beebreeder 

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Love the old video footage MM, I was not having a go, that just works for me, left the feed hole open in one nuc last winter as the 4 inch space had fondant in, they filled the brood area and the roof with wild comb, bees everywhere, mess to clear up, but enough bees to move into a full box and that is 14x12
kev
PS I do have some insulation in the roof of my dartington and the dummy boards are insulated as per Dartington plans
 

JamesB 

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watching that beekeeper at work , reminds me so much of my old man, with his hat and bare arms lol,
Id advocate every new beek watch these old vids learning from history and adding new ideas and ofc your own adapted way and personality :)

Yes insulate but as muswell advises you need to be able to prevent damp and have small gaps, if you have too many or too much the bees will seal them up with propilis, they need to be warm but not too warm else they could be in trouble,
Also remember a man made hive mimics a bees surroundings, naturally bees wont have quilts and wire mesh floors etc and tbh in the wild they will look after themselves sealing unwanted draughts etc as Muswell says a home in a tree is far far better than a hive in the respect of having plenty of wood around them :)
Main concern is whether they have enough stores for winter and ofc todays issues with health etc
 
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madasafish 

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I live in darkest northernmost Staffordshire.. and although obviously not as cold as Finland (!).. it is noticeably colder and wetter than Southern England.

So frankly, anyone in Southern England who dismisses the value of insulation --- is irrelevant due to their mild winter weather.

Do you get 3 weeks plus of lying snow? Really cold nights of -15C or lower in a row? Heavy driving rain for what seems like weeks on end? Frosts in May.. or even snow in June?

Most cases the answers are no. We do (snow in June roughly once every 10 years. May frosts this year)

So your responses on insulation are only relevant to your areas - which have mild winters . And where snow is a rarity. And May frosts are virtually unheard of..

The maximum temperature today was 12C. It's a cold week.. And in August we had similar for a week.

My point is: Lincolnshire or Devon or Wiltshire are fortunate to have mild weather vis a vis the rest of the country. Your need of insulation is not high...


Anyone North of Birmingham is likely to be far less fortunate.
 

kazmcc 

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Yikes! I thought Manchester was bad. It just goes to show how different the climate is in various parts of our small island. Who would have thought?
 

Poly Hive 

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I keep mentioning our micro climates to not much avail...

However from personal experience from much further north and now here in East Mids I can tell you that insulation is highly beneficial for the bees.

PH
 

kazmcc 

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I keep mentioning our micro climates to not much avail... PH
It is amazing how much I've started to notice about my surroundings since starting to keep bees. I have never taken any of this into considerstion before. I can now see even more potential in bee keeping for schools. I know my children are more aware of the weather and wildlife since I started bee keeping, even my 4 year old told his grandma that the weather was too wet to have a look at the bees, and that wasps were upsetting mummys bees :) Funny what they take in when you think they're not listening.
 
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