Insulation?

[Erichalfbee]

All right, you win.

How refreshing.
Welcome and I do mean that.

 

[Earthboy]

Thank you! That I am on self-imposed exile here, sick of another forum across the pond, many of you must be thinking I am a novice bee-haver. It ain't so. I am a bee researcher with a Ph. D. working on treatment free beekeeping against v. mites and now SHB's in US. Here is my FB where I show my feral bee rescues:

 

[Erichalfbee]

Thank you! That I am on self-imposed exile here, sick of another forum across the pond, many of you must be thinking I am a novice bee-haver. It ain't so. I am a bee researcher with a Ph. D. working on treatment free beekeeping against v. mites and now SHB's in US. Here is my FB where I show my feral bee rescues:

Welcome again. We may have just the group for you. I shall go away and ask

 

[Finman]

Well now...

Now I know where Earth boy lives. Behind the pond.

Oklahoma 36 latitude.

Gibraltar 36 latitude.

My latitude is 60. Same as Alaska's Anchorage.

Not much common to discus about insulation.

 

[pargyle]

Yes you will, you won't be able to resist

BB (100 metre swimming badge)

Yes ... he won't.. will he ?

PA (Cub Scout Knitting badge)

 

[Lottie]

I’ve just cut the celotex to the size of frame, sealed the edges with aluminium tape and will use stuck in cocktail sticks instead of lugs. Someone on here advised this some time back and it works fine.

I made double ones using 2 old frames, celotex on the outside and kingspan in the middle...all taped together

 

[Earthboy]

Excellent. In my area, winters are not that cold; the only insulation I offer is a thick plastic bag. I entomb the whole box in it now that one does not need to worry about the moisture build up inside as the weather thaws. Not only does it cut the draft but it also keeps moisture inside.

 

[jenkinsbrynmair]

I have repeatedly asked for a counter argument to mine and neither you nor anyone else has provided one.

Olszewski , K. (2007) Winter-hardiness of Buckfast bees under specific weather conditions of areas with alternating influences of maritime and continental climate. Journal of Apicultural Science 51(1), 73-82 2007
Olszewski reported winter food consumption [in kilograms] per colony between 1 November and 21
March (141 days) in Poland by Buckfast and Norwegian x Caucasian bees exposed to different
overwintering methods (data from 2004 and 2005 winter were pooled together). Data from his Table 4 are
shown here:

Overwintering method	Buckfast​	Norwegian x Caucasian​
Mean​	CV​	Mean​	CV​
Uninsulated	11.72​	3.01​	9.7​	15.03​
Insulated	9.72​	17.63​	7.8​	25.59​

Taking the average of the breeds, the consumption rates were 0.076 kg/day for uninsulated hives and 0.062
kg/day for insulated hives. In the study period, minimum temperatures ranged from +1 to -7°C. From the
maximum and minimum temperatures given for November to February the average was calculated as
0.43°C.

 

[yukonbees]

Not too sure if I want to get involved in this thread on insulation I am located in the Yukon. We have no choice here on using insulation. Over the last 3-4 years I have been doing a lot of reading and hive monitoring in my wintering hives. My bees are hive bound from October to mid April before getting their 1st decent cleansing flight. Therefore heat conservation is critical to ensure low stores consumption, produce less metabolic water and reduce the need to cleanse. Bees generate heat in 2 ways (resting metabolism = just moving around & endothermic = shivering of muscles). As stated in this thread, bees are able to "heat" their insulated enclosure and bee in very loose clusters at Ts above above -10 to -15C (depends on enclosure).

On the cluster shape, I have enough sensors in my single brood hive and another double brood hive to approximate the cluster shape/size and location. Small volumes (single) will have an hemispherical shape where the core of the cluster is actually along the upper insulated surface of the cover. I use R30-R40 to coverings and R10+ on the sides. My double hives have very weird shapes but tend to use the sidewall as part of their cluster. The R-value of the wall is higher than anything the cluster can create.

Using my data (Poly - insulated) and data from a beekeeper in the US using a wood only enclosure I was able to illustrate that in a wooden hive the cluster is the primary mode of cold survival at low temperatures (Tin=Tout) R2>0.9 and the the relationship switches when spring brood rearing commences (Tin>Tout). Using basic enclosure heat loss calculations Vs outside temperatures.
In my polys, Tin >> Tout. During our typical cold snaps <-40C the Delta T with temperatures just below the cluster is ~40C and ~60C inside the cluster.

So basically my bees consume less honey in winters 10x to 20x colder & (200+ days Vs 90 days). A single consumes about 20 to 30lbs and a double is about 50lbs. I am 4 for 4 - 2019, 8 for 8 - 2020 and so far 10 for 10 - 2021, including the overwintering of 5 frame nuns outdoors. I have lost a couple of hives over the years early summer to Nosema C.
You can read more here if you like. I wrote this article back in November. I now have more data and few more observations. North of 60 Beekeeping - Winter 2020 Monitoring
Here is thermal image video of my cluster with camera pointing upward into a very loose cluster. (I have a pdf loco link to the video in the description on winter hive disturbances)

 

[Nannysbees]

Not too sure if I want to get involved in this thread on insulation I am located in the Yukon. We have no choice here on using insulation. Over the last 3-4 years I have been doing a lot of reading and hive monitoring in my wintering hives. My bees are hive bound from October to mid April before getting their 1st decent cleansing flight. Therefore heat conservation is critical to ensure low stores consumption, produce less metabolic water and reduce the need to cleanse. Bees generate heat in 2 ways (resting metabolism = just moving around & endothermic = shivering of muscles). As stated in this thread, bees are able to "heat" their insulated enclosure and bee in very loose clusters at Ts above above -10 to -15C (depends on enclosure).

On the cluster shape, I have enough sensors in my single brood hive and another double brood hive to approximate the cluster shape/size and location. Small volumes (single) will have an hemispherical shape where the core of the cluster is actually along the upper insulated surface of the cover. I use R30-R40 to coverings and R10+ on the sides. My double hives have very weird shapes but tend to use the sidewall as part of their cluster. The R-value of the wall is higher than anything the cluster can create.

Using my data (Poly - insulated) and data from a beekeeper in the US using a wood only enclosure I was able to illustrate that in a wooden hive the cluster is the primary mode of cold survival at low temperatures (Tin=Tout) R2>0.9 and the the relationship switches when spring brood rearing commences (Tin>Tout). Using basic enclosure heat loss calculations Vs outside temperatures.
In my polys, Tin >> Tout. During our typical cold snaps <-40C the Delta T with temperatures just below the cluster is ~40C and ~60C inside the cluster.

So basically my bees consume less honey in winters 10x to 20x colder & (200+ days Vs 90 days). A single consumes about 20 to 30lbs and a double is about 50lbs. I am 4 for 4 - 2019, 8 for 8 - 2020 and so far 10 for 10 - 2021, including the overwintering of 5 frame nuns outdoors. I have lost a couple of hives over the years early summer to Nosema C.
You can read more here if you like. I wrote this article back in November. I now have more data and few more observations. North of 60 Beekeeping - Winter 2020 Monitoring
Here is thermal image video of my cluster with camera pointing upward into a very loose cluster. (I have a pdf loco link to the video in the description on winter hive disturbances)

Fascinating

 

[The Poot]

Fascinating

 

[Erichalfbee]

Not too sure if I want to get involved in this thread on insulation I am located in the Yukon. We have no choice here on using insulation. Over the last 3-4 years I have been doing a lot of reading and hive monitoring in my wintering hives. My bees are hive bound from October to mid April before getting their 1st decent cleansing flight. Therefore heat conservation is critical to ensure low stores consumption, produce less metabolic water and reduce the need to cleanse. Bees generate heat in 2 ways (resting metabolism = just moving around & endothermic = shivering of muscles). As stated in this thread, bees are able to "heat" their insulated enclosure and bee in very loose clusters at Ts above above -10 to -15C (depends on enclosure).

On the cluster shape, I have enough sensors in my single brood hive and another double brood hive to approximate the cluster shape/size and location. Small volumes (single) will have an hemispherical shape where the core of the cluster is actually along the upper insulated surface of the cover. I use R30-R40 to coverings and R10+ on the sides. My double hives have very weird shapes but tend to use the sidewall as part of their cluster. The R-value of the wall is higher than anything the cluster can create.

Using my data (Poly - insulated) and data from a beekeeper in the US using a wood only enclosure I was able to illustrate that in a wooden hive the cluster is the primary mode of cold survival at low temperatures (Tin=Tout) R2>0.9 and the the relationship switches when spring brood rearing commences (Tin>Tout). Using basic enclosure heat loss calculations Vs outside temperatures.
In my polys, Tin >> Tout. During our typical cold snaps <-40C the Delta T with temperatures just below the cluster is ~40C and ~60C inside the cluster.

So basically my bees consume less honey in winters 10x to 20x colder & (200+ days Vs 90 days). A single consumes about 20 to 30lbs and a double is about 50lbs. I am 4 for 4 - 2019, 8 for 8 - 2020 and so far 10 for 10 - 2021, including the overwintering of 5 frame nuns outdoors. I have lost a couple of hives over the years early summer to Nosema C.
You can read more here if you like. I wrote this article back in November. I now have more data and few more observations. North of 60 Beekeeping - Winter 2020 Monitoring
Here is thermal image video of my cluster with camera pointing upward into a very loose cluster. (I have a pdf loco link to the video in the description on winter hive disturbances)

Thanks and welcome.
I spent one June and July in the Yukon visiting an artist friend in Whitehorse then doing “ the sights “
Happy days before mortgages children and career stuff.

 

[Finman]

Yokonbee

How much you hives consume winterfood from feeding to next summer?

I extract all honey from brood box and I feed on average 20 kg sugar/hive.. In spring I even stores between hives when needed.

How much bees consume in a day, that data I do not need.

Hives have different consumptions, and I check the hives after cleansing flight.

My friend weighs the consumption of every hive. He uses data in breeding queens.

 

[yukonbees]

From the video, I almost get a feeling that bees are heating the cluster from below (In a well insulated hive). I am sold on the singles hive management approach going into winter. The bees just seem less stressed, lower entrance mortality. I just had a quick look a couple of days ago (top check only), 2C to -3C sunny during check. -30C this morning here... I have taken a very data driven approach in all seasons to link colony behaviours (good & bad) with actual environmental cues.

 

[yukonbees]

Finman,

Consumption estimate is about 0.5 kg/week (Single). I haven't a chance to do a full check yet, so I put 1 kg of fondant above each hive just in case (2 weeks of food). Our winter has been cold and we have 185% out normal snow level so spring will be very late. We have about 1 to 1.5 m of snow pack here and much more in the mountains.

Chart one is the estimated consumption based on heat loss (Wooden hive and it shows period where brood rearing starts)
Chart two is my winter estimated energy consumption modelled on Southwick Metabolic rate curve.

I take an average T below the cluster to calculate the meta rate vs the typical T ambient which is not relevant based on my findings. Remember, in wooden hives Tin=Tout....

 

[yukonbees]

By the way, I do not use any type of upper entrance. I am currently working out the heat losses through the lower entrance. Fortunately, a lot of air mixing occurs that effectively pre-heat cold incoming air thus improving heat conservation. Upper entrances in insulated hive creates a thermal syphon pulling warm air out the top and sucking in cold air from the bottom, thus eliminating this heat transfer and increasing honey consumption. D Mitchell describes this in his ABJ article...

The attached chart is the theoretical ventilation based on temperature differences, the cluster mass, frames, etc... would slow this flow down. But still interesting to see the air change out and very heat losses associated to top entrances. Not an issue in warmer climates (I will that debate up to you), but critical in very cold climates.

 

[Finman]

I have used about 30 years polyhives. It has different moisture problems than wooden hives. I have solid floors.

Every hive has 15 mm hole in the front wall. Small air flow goes via the hole. It moves moisture from the hive. I can see it from the snow, which flow makes in very cold weather.

If the main entrance is stucked with snow, bees get air via upper entrance. In spring bees use the upper entrance, and it is a short way to the cluster .

My climate is not bad. Coldest weathers are -20C.

In north guys over winter hives under snow.

In South Finland snow is often wet and bees do better in fresh air than under wet snow.

 

[yukonbees]

I use pieces of wood to protect my lower entrances from snow, wind and blockage. For those who use top entrances here they keep it at about 3/4" did and use very small lower entrances to reduce flow through ventilation.

 

[Finman]

Do you have woodpeckers and bears there

 

[yukonbees]

Yes.... on both. I use electric fences around my bee yards for both black and grizzly bears. Woodpeckers luckily don't care about my hives (last 8 years).