Insulation and Heat

[Finski]

I decided to break out my electric heaters to boost the warmth (and early brooding) in a couple of my hives where the number of bees have dwindled to the point where the hives are acting like freezers.

Would you care to guess what happens in a 38mm thick foam hive when you add in 36 watts of electric heat?

I have used 10 years 6-15W heaters in spring in my hives. I have only good to say.
I have heated 30 hives.

I have 40 mm thick poly boxes.

With pollen patty and heating I have achieved 3 fold build up in big hives
Small hives are prisons of they size.

Like last spring I had in one hive 15 frames brood even if willow had not started to bloom yet.

.
If you look here, I have explained 6 years electrict heating on this forum.

http://forum.beemaster.com/index.php?action=search2;params=YWR2YW5jZWR8J3wwfCJ8YnJkfCd8MnwifHNob3dfY29tcGxldGV8J3x8InxzdWJqZWN0X29ubHl8J3x8Inxzb3J0fCd8cmVsZXZhbmNlfCJ8c29ydF9kaXJ8J3xkZXNjfCJ8c2VhcmNofCd8ZWxlY3RyaWN0IGhlYXRpbmc=;start=30

[Bush_84]

Do you do this in the spring with all of your hives or just select hives?  If not all hives then how do you determine which hives to give heat?  Where do you put the heat source?  Also when do you applying relation to your first flow? 

[derekm]

insulation is resistance to heat flow  it has no directional preference. its a scalar
radiative losses exceed radiative gains  in winter(see other posts)


Roughly speaking .. if you have a smaller heat source(less bees) to maintain the same temperature you need  
either/both smaller surface area, higher thermal resistance.

There are complications in that the air  temperatures are stratified i.e. hotter at the top,  and as heat flow is proportional to temperature difference, the surface area and insulation at or near the top have a greater  effect than lower down.

If you add:

• mass transfer (air flow out/through of the box)
• phase changes (condensation)
• Internal and external natural and forced convection.

it adds further complications but the above still holds true.

[rdy-b]

I decided to break out my electric heaters to boost the warmth (and early brooding) in a couple of my hives where the number of bees have dwindled to the point where the hives are acting like freezers.

Would you care to guess what happens in a 38mm thick foam hive when you add in 36 watts of electric heat?

the bees die- keep us posted   RDY-B

[Michael Bush]

All of the stuff about "the bees don't heat the hive so it doesn't matter if it's big or small or if it's insulated", I think are perpetuated by people who have never lived outdoors.  I worked in construction in the panhandle of nebraska.  We worked until it get lower than -10 F.  that was our cutoff.  We worked outside, inside heated and unheated, insulated and uninsulated, partially finished, completly finished etc.  I've also camped in the winter all my life, lived in a tipi, build many shelters of everything from tarps, to branches and sod.  That will give you a much different view of what does and does not matter.  A human in those circumstances is not much different from a cluster of bees.  I am not "trying" to heat my tent or any other shelter I'm in.  I'm just "trying" to heat myself.  But almost everything affects that.  If it's sunny, I'm much better if I can get some of that sun. 
But if it's not, I'm much better off with ANY amount of insulation.  Thin cloth is colder than thick cloth.  Dark cloth is colder than white cloth.  Sealing up more drafts around the bottom, even with an open front, makes it MUCH warmer.  Discounting how much little things affect how warm you are is a mistake.  I'm not saying I have all the answers, but I assure you the answers are not simple, they are a complex thing.  Warmth isn't just about temperature.  It's about heat loss.

http://www.bushfarms.com/beesscientificstudies.htm#overwintering

[rdy-b]

 the answer is bigger cluster more heat-yes and heat loss-
the answer is not heating a beehive so the bees are in a cosey environment
and break cluster-actually bees do better when temp is maintained at point of
cluster for extended periods of time -bees are keep in cold rooms not hot houses
  its what is going on in the cluster that makes the diferance --RDY-B

[S.M.N.Bee]

I run insulated hive covers as well. I will continue to run them because I believe they make a real difference here in Minnesota. The thing
I feel is most important has been posted here time after time." Large healthy clusters of bees going into winter with enough food equal live bees in spring"

John

[edward]

Has anybody used the rolls of fiberglass insulation around their hives?

We have wooden hives that have fiberglass insulation in Sweden, they cost 5X more than poly hives are heavy and hard to work.

I bought a bee yard last year with theses hives and I was going to burn them before I found out what they are worth, I am now going to fill them with bees and sell them to some one who romantically wants to keep bees in them at the end of there garden.

mvh edward 

[Bush_84]

Has anybody used the rolls of fiberglass insulation around their hives?

We have wooden hives that have fiberglass insulation in Sweden, they cost 5X more than poly hives are heavy and hard to work.

I bought a bee yard last year with theses hives and I was going to burn them before I found out what they are worth, I am now going to fill them with bees and sell them to some one who romantically wants to keep bees in them at the end of there garden.

mvh edward 

I don't think I made it clear enough what I was talking about.

http://www.google.com/search?hl=en&client=safari&tbo=d&biw=1024&bih=672&tbm=isch&sa=1&q=fiberglass+insulation+roll&oq=fiberglass+insulation+roll&gs_l=img.3..0i24l3.15098.16240.0.16991.5.4.0.0.0.0.518.686.0j1j5-1.2.0...0.0...1ac.1.2.img.TE_xm7XBWHE

Bigger link than I thought, but I meant those rolls of fiberglass insulation. 

[BlueBee]

I haven’t because I don’t see any advantage of fiberglass over polystyrene.  It’s wet outside, hives get wet.  If fiberglass gets wet, its insulation value is completely worthless.  I don’t even like to use the stuff in my house, let alone a bee hive.  It’s also a poor insulating material if there is ANY chance of air movement because air will move right through the stuff. 

In a pinch, it might be interesting to wrap a hive in the stuff and cover it with a black garbage bag.  The garbage bag will absorb a lot of heat from the sun and the resulting temperature gradient might be sufficient to make such a configuration act like a weak thermal version of a diode.  Heat flows in during the day but is resisted by the insulation from flowing out as quickly at night. 

[BlueBee]

the physics is quite straight forward..  and Bluebee you are wrong... I assume you are just being provocative... in the vernacular of Northern England, this is a wind up.

If the volume of bees to the surface area of the foam is high, then foam works very well.  If the ratio is low, then the temp in the hive is going to track the average daily temp which is about 21F/-6C here right now.  That’s what I call a freezer.  What temperature is your freezer set to? 

The few watts from a weak cluster of bees just get sucked up and absorbed by all that cold honey as opposed to warming up the hive.  It’s a losing battle.  In such hives the bees just keep moving slower and slower until the finally stop for good.

[BlueBee]

With regards to electric heat.  My hives lived the last time I used electric heat while Michigan averaged 70% losses.  So I’m not sure what logic would suggest all the bees will die this time   I would prefer NOT to resort to electric, but if I have a weak colony in a foam hive in Michigan, it’s going to croak without some help.  Even if by some miracle it doesn’t freeze now, it will be robbed out and killed as soon as the big colonies are able to fly.  Adding more sugar or honeyballs isn’t going to solve the freezer problem or the future robbing problem. 

The only way a cold foam hive warms up is with more bees (nature’s heaters), or more solar gain, or electric heat.  It takes 21+ days to make more bees so that isn’t a quick fix.  Foam doesn’t conduct Solar gains into the bees so you can scratch that one off.  That leaves electric heat as about the only option.

I did not get a 3x spring buildup the last time I added electric heat, but Finski’s report is very encouraging.  Last time I didn’t feed.  This time I will be feeding;  protein and probably light syrup to get them going.   FInski do I need to put a bowl of water in there too?

[Finski]

   FInski do I need to put a bowl of water in there too?

Stop drinking. That is all what I say.

[derekm]

the physics is quite straight forward..  and Bluebee you are wrong... I assume you are just being provocative... in the vernacular of Northern England, this is a wind up.

If the volume of bees to the surface area of the foam is high, then foam works very well.  If the ratio is low, then the temp in the hive is going to track the average daily temp which is about 21F/-6C here right now.  That’s what I call a freezer.  What temperature is your freezer set to? 

The few watts from a weak cluster of bees just get sucked up and absorbed by all that cold honey as opposed to warming up the hive.  It’s a losing battle.  In such hives the bees just keep moving slower and slower until the finally stop for good.

A freezer is an insulated cavity with a  heat pump. I dont recognise any heat pumps in a winter colony.

Conventional hive geometry is very poor for higher temperature heat retention.  It seems to assume that the air inside is a solid not a fluid.
Cold honey? where does this come from. The honey starts out warm, then heat flows hive resisted  by its themal conductivity and delayed by its  thermal mass.
If your surface area is too large for the heat source... Change it.
If you are getting mass transfer taking heat away  .... Seal it.

Bees in tree nests have all of this solved. Like the ball catcher they have a good solution to the differential equations of the problem.
(p.s. they have feral bees in Alberta!)

[Finski]

.
This is good to read

    The Biology and Management of Colonies in Winter - CAPA Bees

www.capabees.com/main/files/pdf/winteringpdf.pdf

[T Beek]

 quote author=BlueBee link=topic=40145.msg340656#msg340656 date=1360711084]
Of course their homes are like freezers!  You mean to tell me that in your 66 years you never made an igloo out of snow?  I have, and YES, they are like freezers.

Sometimes I wonder if Finski is actually posting from somewhere in the tropics?

[/quote]

Oh My!  Me too!

P.S. one lit candle inside an igloo will have you near naked in no time 

[Finski]

Sometimes I wonder if Finski is actually posting from somewhere in the tropics?

where  candle is inside an igloo , If I could see him   naked

Oh My!  Me too!

P.S.  

Even if you are two pervos that was good. I told your case to Micah and look what he did

Baby Micah Laughing Hysterically at Laundry Basket

[Michael Bush]

>You mean to tell me that in your 66 years you never made an igloo out of snow?  I have, and YES, they are like freezers.

I have, and the igloo was quite warm.  So were the snow caves I've built.  Anything that is only 32 F when outside is -20 F is warm.  Anything that is out of the wind when outside it is howling is warm.  A reasonably sized igloo or snow cave with a candle, can get VERY warm...

[Beeboy01]

I've had a little experence with warming weak hives during the winter when I was beekeeping in Pennsylvania. One of the main things that I found needed with wintering hives is air proper flow in a hive which prevents moisture from building up and causing condensation. Heating a hive not only allows the bees to spread the cluster out it also increases the air flow in a hive which helps remove the moisture generated by the metabolic activity of the bees. I heated my hives using a flat 25 watt bird bath heater slid in between the solid bottom board and the screened bottom board. This allowed the heat to rise past the cluster picking up moisture and then vent out past the inner cover. Since I've moved to Florida I haven't had the need to heat any hives. Just adding my thoughts about heating hives.
 

[BlueBee]

A bird bath heater slipped under the bottom?  Now that is ingenious.  My heaters are a series of power resistors potted in cement that can be run on either AC or DC power.  I also put them under the hives and the heat rises through the bees.  My configuration also resulted in the removal of all condensation.  Each of my heaters can put out 12watts each.  I can PWM them when run off DC or triac them when running of AC to modulate the wattage from 0 to 12 watts.  I've got 3 in a full sized hive right now resulting in 36watts.

The amount of watts you need kind of depends on your goals.  My goal is to get some February brood cycles going in a couple of weak hives so I've added more watts that would be needed to simply keep the bees from freezing.