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Author Topic: Heating hives  (Read 29796 times)

Offline mushmushi

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Heating hives
« on: August 30, 2011, 12:20:24 pm »

What are the advantages and disadvantages of heating a hive in northern climates  ?


Hypothetical advantages:

  • Decreased moisture
  • Faster Spring build up
  • Faster curing of syrup in Fall
  • Less sugar/honey consumed
  • Better overwintering rates
  • Overwintering weaker colonies

Hypothetical Disadvantages:
  • Difficult to control the heating levels (needs monitoring)
  • Risk of cooking the bees
  • Cost (cables, heating unit, power, etc)
  • No overwintering gains
  • Dryness inside the hive (little water left for the bees?)
  • Electromagnetic radiation
  • More work for the beekeeper
  • Increased consumption of sugar/honey

Has anybody tested this ?

What kind of heater would be suitable ?  Would a 25W infrared heater on a timer work ?

Cheers

Offline BlueBee

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Re: Heating hives
« Reply #1 on: August 30, 2011, 02:40:19 pm »
As many know and are probably tired of hearing about; I’m an infamous bee hive heater :-D 

My experience would concur with the advantages Mushmushi listed. 

As for the disadvantages, here’s what I found:

Concern:  Difficult to control the heating levels and worry about cooking the bees.
Response:  This depends upon what your goals are.  If you only want to give the bees a break from a forecast week of an arctic blast (ie -20C to -30C spell) you could simply plug in a 10Watt heater (or incandescent light bulb) and let it run day and night through an extreme cold spell and never have to worry about cooking the bees when it is so cold outside.  10watts doesn’t warm a hive by much when it’s -20C outside!  However the warmer convection currents rising up around the bees cluster may be greatly appreciated.  If your goal is to minimize honey/stores consumption in the winter, then you would need a little controller to maintain the hive temp around 5 or 6C (low 40sF).  If you’re trying to baby a small colony through winter, then 15C (60F) works well. 

Concern:  Cost.
Response:  Yes, there is cost with electric heating, but there is also cost with buying new packages every spring.  All my electrical parts cost less in total than a single new package of bees.  I use an old computer power supply for power and some homemade cement/resistor things for heat.  Total cost for a simple system is the cost of a bag cement, about $1 of resistors, and an extension cord.   Plumbing heater cables have also been used by some for heaters.  Cabling is the most expensive part.  If you want to control a hive to a fixed temperature then you need a thermostat for the heaters.  For DC heaters you can make one of those out of a simple op amp circuit (no programming needed) for under $5 in parts.  If you want a more sophisticated controller and know how to program a micro controller, you can select from a ton of low cost 8-bit micros that are more than capable of reading temps from a thermistor and controlling the heaters with FETs.  An 8 bit micro costs $1 to $4 depending upon what you want.

Concern:  No overwintering gains?
Response:  You lost me here, I don’t know what you mean.

Concern:  Dryness in the hive.
Response:  Yes, this can be a problem in the spring.  Heated hives are very dry.  You never have to worry about wet bees in a heated hive.  Come brood season, I think you would want to add water to your hives somehow.  A sponge, a coffee/food lid filled with water, or water poured into comb. 

Concern:  Electromagnetic Radiation
Response:  EM radiation is generated by large current flows (your power company lines) and high frequency noise where there is a conductor that acts like an antenna and impedances are not matched.  You really have to TRY to build a transmitter if you want to make a significant level of EM radiation.  There will be more EM from cell phones and power transformers than bee heating equipment.   If you go with a simple Christmas light heater, how much EM is in that?  My stuff is powered by a computer power supply.  Those use switching in the low MHz range to generate DC voltage.  That does generate some noise, but you need a pretty long wire (antenna) to radiate 1MHz.

Concern:  More work for the bee keeper.
Yes.

Couple of items you didn’t list:

Concern:  A warm hive will be more conducive to pests like wax moths.
Response:  Yes.  Unless you’re babying a nuc, it may be unwise to heat the hive above 12C (55F). 

Concern:  What if the power goes out?  Do my bees die?
Response:  If the power goes out, your bees will have to cope with the cold like all the other bees out there.  An extended period of cold may do them in, just like all the un heated bees.  However a power outage does not mean immediate death to your bees! 

Concern:  The bees will keep brooding all winter long.
Response:  I have not seen this with my carniolans or Italians, but I never say never. 

Concern:  Electrically heated hives will run my electric bill through the roof.
Response:  No it won’t.  Running a 10watt bee heater will be under 5 cents per day in most of the USA.  So $1.50 per month.  Most of us don’t have -20C all winter long, maybe you just run a heater for a month or put it on a timer?  The power cost depends upon how many watts of heat you want to pump into your hives and for how many hours.  Say you add a 10 watt heater to your hive and run it 24 hours a day during a cold spell.  That is 10w x 24hour = 240watt-hours of power you need to buy from the power company per day.  Electric power is priced by the kilowatt hour used in the USA.  In the Midwest power usually costs about 12 cents per kw-hour (can be double that on the east coast, or Calf).  So 0.240kw-hours x 12 cents/kw-hour = 2.88 cents per day to run a 10watt bee heater.  How much does it cost for new packages of bees from the south?  How much is a pound of sugar?  Electricity is cheaper.

Offline derekm

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Re: Heating hives
« Reply #2 on: August 30, 2011, 03:33:49 pm »
Not worth it unless you insulate a lot!- a small bare wooden hive dissapates around 5w per degree C. 25w = 5 degree C. (thats 9F). The Artic blast of -20C is only going to come upto -15C.
You can insulate down to 0.3W per degree C using standard(in the UK at least) building materials. Your 20W now gets you 60C difference.
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 mushmushi

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Re: Heating hives
« Reply #3 on: August 30, 2011, 03:48:17 pm »

BlueBee, thanks for the tips.

By "No overwintering gains" in the hypothetical disadvantages category I meant that the rate of overwintering might not change.

How many hives are you heating every year ?

Do you have your heated hives on 1 or 2 deeps ?

I would like to know more about your cement heaters.
Do you put them underneath the bottom screen ? How much heat can be produce ?

I was thinking of wrapping my hives with the bee cozy wraps. Link is here.

I would put the heater under the sealed screen board.

Also, I was thinking of monitoring the temperature of one or two hives and based on those readings the heat would be on or off.

Offline Finski

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Re: Heating hives
« Reply #4 on: August 30, 2011, 05:00:14 pm »
..
I have heated hives 7 years. I put  terrarium heater cables into every hive in spring.
Heaters are 15 w - 7 w.
3 w has no inlfluence.


I have  wintered small colonies with electrict aid. Heating is like a bigger cluster.

Last winter was very bad. When I trickled my hives in December, I noticed that varroa had demished  5 hives too much. I put to them 7 w heating.

The winter was unespectedly hard, but thse weak colonies were in good condition in spring.

I have wintered 2 frame colonies with electrict and the nuc in a firewood shelter.
The colony has only value of queen and trouples begin in spring - from where you get 5 frame  colony tothe queen?
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Offline Scadsobees

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Re: Heating hives
« Reply #5 on: August 30, 2011, 05:46:21 pm »
Concern: what if one of the kids gets electrocuted sledding in slush over the 200 foot extension cord?  :roll:
Rick

Offline JRH

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Re: Heating hives
« Reply #6 on: August 30, 2011, 09:33:14 pm »
"Concern: what if one of the kids gets electrocuted sledding in slush over the 200 foot extension cord?"

Same concern if one of the kids gets hit by a meteor on the way to the school bus.  Greater concern if (god forbid) the kid walks to school.

Offline BlueBee

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Re: Heating hives
« Reply #7 on: August 30, 2011, 11:26:08 pm »
I think Scads raises a valid concern.  We all view risks differently so one shoe doesn’t fit all.

I will just stick with the facts.  Yes 120VAC is deadly.  It only takes about 50milliamps of current going through your heart to stop it.  That’s just a little more current than is used to light a little LED indicator.  It doesn’t take much to kill you IF it flows through your heart muscle.  Muscles are controlled by nerves which are controlled by electrical potentials.  If you mess up the nerves (with external voltage), you mess up the muscle.  If that muscle happens to be your heart, then warm bees is no longer your biggest problem. 

An electrically safer way to provide power to bee hives would be to use a 12Volt DC power source like a battery, or a long feed cable feeding 12volts DC to the hives.  I have tried feeding 12volts DC back to my hives through long heavy gauge landscape lighting wire (10 or 12 gauge, I can’t recall which).  However you just get too much voltage drop over the cabling to be efficient; even with thick wires.  By the time my 12volts DC got back to my hives, it was down to 9volts when flowing a few amps (actually about 9 amps).  That means I was loosing 25% of my heating power just in the feed cable!

I ended up switching back to a 120VAC extension cord because of the voltage drops in the wire.  If you drop a few volts over 120VAC you can still get 12VDC out the other end.  However as Rick points out, it is more dangerous.  It is also dangerous to use Christmas lights, but that is for a different discussion.

Offline Finski

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Re: Heating hives
« Reply #8 on: August 31, 2011, 12:01:29 am »
.
Hypotetical risk list is not real.

It is easy to see how the bees react on heating.

For winter put the heater over the top bar or on side. So it doest not break the wintering cluster. Another place is a side.

Once I bought two heating cables which irritated bees so that bees stung the cable full of sting. It was like a tail of  squirrel.
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Offline BlueBee

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Re: Heating hives
« Reply #9 on: August 31, 2011, 12:03:17 am »
As Derekm, points out, you waste a lot of energy (bee heat and electrical heat) if your hive isn’t insulated.  19mm thick wood has almost no insulation value.  It would seem sensible to me to add insulation before playing with electric heat.

I listen to Finski when it comes to heat and insulation.  He has more years in than I do.  I just started experimenting with electric heat last winter.  My full sized hives were all mediums last year, 3 mediums per hive and insulated in 2” foam.  My nucs were 2 to 3 frames of bees going into winter.  They didn’t build up as much as I hoped before winter.  Everything survived winter, even the 2 frame nucs.  The reports I heard was that Michigan lost at least 60% of their hives last year.  I can definitely attribute the 2 frame nucs survival to electric heat, I suppose the rest could be debated (maybe I was lucky)

As Finski preaches, the bees themselves make heat energy, probably on the order of 10 to 40 watts.  So we already have an energy source to keep the bees warm if we provide them with good insulation.  Electric heat really comes in useful if you end up with a weaker than hoped for colony going into winter.

Offline Michael Bush

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Re: Heating hives
« Reply #10 on: August 31, 2011, 12:57:45 am »
http://www.bushfarms.com/beesnucs.htm#overwinternucs

Here are some pictures of overwinter nucs with a small space heater in the gap at the back.  2" of Styrofoam top, bottom and ends.

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Offline BlueBee

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Re: Heating hives
« Reply #11 on: August 31, 2011, 01:58:03 pm »
Here’s a photo of my heaters.  Each heater is a shade over 10watts.  This whole stack cost maybe $10 to make.   
Here is a forum link how to make these things here. http://forum.beemaster.com/index.php/topic,32037.0.html

The bottom unit of my full sized hives is actually a heater box.  There is a screen on top to keep the bees out of the heater area so I can manipulate things in there as desired.  The brood boxes sit over top of the heater box.  Since heat (actually hot air) rises, putting the heater box on the bottom of the stack makes the physics work easier, but other configurations would also work.  Convection currents will distribute heat. 

I didn’t find any photos on the computer of my full sized heater boxes, but here is a photo of a smaller heating box used in another hive configuration.  I add the brood boxes on top of this and add foam shells over the whole thing for insulation.


Last winter I wintered in 3 mediums.  I decided to stop using mediums for brood chambers this summer so I will have different winter configurations this year.  I switched back to using deeps and extra deeps for brood chambers.  So this winter, I will be wintering in 1 deep + 1 medium configurations.  I also have some half frame hives (for mating) and nucs I will be wintering.

My foam nucs look like this.  This design does NOT have a heater box in them.  The bottom deep is brood/stores, the super medium is more stores if they get too big before winter.


Offline T Beek

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Re: Heating hives
« Reply #12 on: August 31, 2011, 02:30:46 pm »
My only concern w/ artificially heating hives is that I 'believe' it fools bees into thinking its warmer outside than it is, causing some to venture out (or maintain a loose cluster when a tight one is needed) when perhaps they should just stay put.  Can't prove it but its what I believe.  I also believe bees will consume more when hive is heated.

That said I remain very interested in the discussion and any other methods folks are experimenting with to keep bees alive and healthy.  Dif strokes for dif folks, Right.

thomas
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Offline Robo

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Re: Heating hives
« Reply #13 on: August 31, 2011, 03:10:20 pm »
Has anybody tested this ?

What kind of heater would be suitable ?  Would a 25W infrared heater on a timer work ?

Cheers

Here is a thread from a few years discussing my use of 7watt night lights.

http://forum.beemaster.com/index.php/topic,11721.0.html

I found anything more than 15watts was to much and made the bees too active.  I found it to work reasonably well,  but ultimately found the switch to polystyrene hives works best for me.
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Offline BlueBee

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Re: Heating hives
« Reply #14 on: August 31, 2011, 06:18:29 pm »
My plan for this winter is to use electric heat as an insurance policy just in case we have a super cold winter.  I may or may not use it since my hives are already highly insulated.  I may just do like Finski and try to boost the spring buildup with electric heat.   

Thomas raises a good concern:  Does heat fool the bees into thinking it is warmer outside than it is?

It might, I still don’t know for sure.  If you play with electric heating, my current advice (subject to change) would be to set the thermostat of your heaters at 55F (12C or less) when it is colder than 45F (7C) outside during the winter.  I would also highly recommend using a landing board on a heated hive.

Last winter my hives had landing boards, but my nucs did not.  If it is relatively mild inside the hive (heaters on), some bees will definitely hang around the entrance soaking up the sun, snow, or just investigating.  I had bees roaming around the entrances when temps were 20F (-6C) outside.  This did not appear to cause problems with the big hives, but it did the nucs. 

The nucs did not have a landing board, so when the bees crawled out to check on the weather, more than a few fell off the nuc entrance hole and into the snow.  A bee that falls into the snow is dead within about a minute.  There is no recovery.  The cold snow sucks energy from their bodies so they can no longer fly to get back in the hive.  If a bee falls in the snow, it is doomed.   

Offline Finski

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Re: Heating hives
« Reply #15 on: August 31, 2011, 06:22:31 pm »
.
It is easy to see, what the heating causes to bees or to cluster.
You just lift the cover and look.

It is important that that bees have a cluster, loose or compact.  when bees are in "cluster sleep", they survive over winter. If they are running inthe hive here and there, they are not in rest mode.
It is you who arrange the system. It no one else.

It is interesting to read what you have met in heating.

To me most important has been that electrict heating has teached the meaning of heat to bee colony.

That puts a mesh floor in a different light in spring.

Some say that a mesh floor is absolutely the best, but on another hand I may see the influence og heating.

One basic factor is the size of bee colony. It is much more easier to rear a big colony in late summer than in spring.

It is almost ridiculous that biggest hives get biggest advantage from heating.  
the basics comes from the volume of ball and the growth of radius with aid of heating.

.we ray "brood area" but it is a ball.

.
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Offline T Beek

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Re: Heating hives
« Reply #16 on: August 31, 2011, 06:51:24 pm »
BlueBee quote;  "If a bee falls in the snow, it is doomed."  Not so, I've been picking bees up from the snow for a few years now and there have been many that have come back after just a few minutes in my hand.  I just push them into the entrance if they're real lively and its above freezing outside.  Not sure how long some were there in the snow but it had to have been more than a minute on some occasions.  Try it sometime. 8-)

Finski;  Aren't you the one who is always telling beeks to leave their hives alone during winter months  :-D (I remember you told me not to even listen w/ a stethoscope as it would cause too much disturbance :-\). Now your advising to just lift the cover and look???? 

At what temps do 'you' stop lifting the lid and looking?   Does artificial heat cause bees to be 'running in the hive here and there' when they should be in cluster?  Just asking.

thomas
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Offline Finski

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Re: Heating hives
« Reply #17 on: September 01, 2011, 12:40:17 am »
.
Beak,
The whole body suffers from stupid head. I am so sorry.
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Offline Michael Bush

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Re: Heating hives
« Reply #18 on: September 01, 2011, 01:15:23 am »
>Thomas raises a good concern:  Does heat fool the bees into thinking it is warmer outside than it is?

With or without heat some fly out and die in the snow.  I see no difference in the amount.
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Offline Finski

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Re: Heating hives
« Reply #19 on: September 01, 2011, 02:15:05 am »
>Thomas raises a good concern:  Does heat fool the bees into thinking it is warmer outside than it is?

With or without heat some fly out and die in the snow.  I see no difference in the amount.


you must set the heat in proper way that the heat does not disperse cluster and winter rest.

Actually I saw last spring that in heated hives bees had less poo, and they did not need to make desperate cleansing flights on snow.

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