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BEEKEEPING LEARNING CENTER => EQUIPMENT USAGE, EXPERIMENTATION, HIVE PLANS, CONSTRUCTION TIPS AND TOOLS => Topic started by: derekm on December 01, 2011, 03:35:02 pm

Title: insulation works - see the result.
Post by: derekm on December 01, 2011, 03:35:02 pm
I decided to to see if a my insulated hives and nucs made a real difference by measuring how much temperature difference bees could make in
a) A wooden hive
b) My foam Nuc.
This is how I did it . I wired up a 12v bulb to variable power supply that would would show volts and current  and set up a pair of temperature sensor to show the temperature difference half way up the the hive.
in the wooden hive (a kit bought from a beekeeping supplies company) after 3 hours with 20w the temperature got to 5 degrees C (9f)  above ambient. 20 W is about what a winter cluster puts out.
I then tried it with my foam hive with just 10W and in 1 hour I got 20C (36f) above ambient.  That means the foam nuc is losing about 1/8th of the wooden hive.  In the wooden hive the outside temp only has to fall to close freezing to produce killing temperature inside the hive, where as in the foam nuc even a small colony is good down to minus 15C. Seeing is believing so I took some pictures.
wooden hive  the power is 8 x2.4 =19.2W temp difference 5C
(http://i298.photobucket.com/albums/mm242/derekm_2008_photo/IMAG0130.jpg)

inside
(http://i298.photobucket.com/albums/mm242/derekm_2008_photo/IMAG0131.jpg)

foam Nuc
the power is 5.3 x 1.9 = 10W temp difference 20C
(http://i298.photobucket.com/albums/mm242/derekm_2008_photo/IMAG0135.jpg)

Title: Re: insulation works - see the result.
Post by: BlueBee on December 01, 2011, 06:44:52 pm
Nice Demo Derekm!  

That should lay to rest that an insulated hive is going to be warmer than a wood hive if the bees are generating heat.  BTW, when you tested in your super PU hive, were you using your open floor design?

I’ve got an interesting situation in my super insulated nucs.  They’re not as super insulated as yours of coarse by they are about 6x better insulated than a wood box.  My nucs were broodless the last time I checked and hence they have no need to make an area of 35C heat for brood.  The only reason they now have for making heat is to keep themselves warm; but they only do that if they’re in a cluster.   And bees only cluster when the temps dip below about 15C (60F)

So once my nucs approaches 16 to 18C inside (say 62F), the bees seem to drop out of cluster and stop generating heat.  With no heat generation in the nuc at that point, the nuc starts to drop in temperature.   Once the temps dip below the bees cluster set point, they re-cluster and start making heat again.  It looks like this process might repeat over and over again throughout winter but I don’t have good enough instrumentation to know for sure yet.  

I’m guessing that even with all my foam, the nucs aren’t going to get above 16 to 18C until there is a CONSTANT heat source when they start brooding early next year.
Title: Re: insulation works - see the result.
Post by: derekm on December 01, 2011, 06:59:43 pm
yes its using the foam grid floor design but only one level of grid. I repeated it tonight and leaving it longer  its gone up to 22c
Title: Re: insulation works - see the result.
Post by: AllenF on December 01, 2011, 08:07:41 pm
Cool set up.
Title: Re: insulation works - see the result.
Post by: SEEYA on December 05, 2011, 07:54:11 pm
Very interesting! What temp should the hive be heated to? If the bees break cluster @60`F, at what temperature would they start cleansing flights? What about 45`F, seems like I remember someone claiming it as the optimum (honey consumption) temperature, to warm the hive to. I like these discussions.
Title: Re: insulation works - see the result.
Post by: Vance G on December 12, 2011, 11:04:16 pm
I have read people who say that the insulated boxes really kicks the mite reproduction into high gear, so it might be prudent to keep checking your mite load when you can. 
Title: Re: insulation works - see the result.
Post by: derekm on December 13, 2011, 07:44:45 pm
Not in my hives so far if aNything the opposite. But remember my hives are warmer than anything on the market. 0.2W per degree compared to 4W per degree.  
Title: Re: insulation works - see the result.
Post by: Country Heart on December 14, 2011, 02:04:11 am
Interesting experiment.

I wonder if anyone has done any testing to determine what temperature the bees prefer?
How would you know?
Title: Re: insulation works - see the result.
Post by: BlueBee on December 14, 2011, 03:58:24 am
Quote
But remember my hives are warmer than anything on the market.
Except when I have my electrically powered bee heaters turned on in my hives :-D

(No, y’all I am not running with the electric heaters this winter.  My nucs are bigger this year.)
Title: Re: insulation works - see the result.
Post by: Michael Bush on December 14, 2011, 04:07:20 am
>I wonder if anyone has done any testing to determine what temperature the bees prefer?
>How would you know?

Well, you probably can't know what they would prefer but you can know what consumes the least stores... and that seems be right around freezing or slightly above.  I'd shoot for 32 F.  They are nice and quiet but not too stressed out.
Title: Re: insulation works - see the result.
Post by: derekm on December 14, 2011, 12:22:34 pm
>I wonder if anyone has done any testing to determine what temperature the bees prefer?
>How would you know?

Well, you probably can't know what they would prefer but you can know what consumes the least stores... and that seems be right around freezing or slightly above.  I'd shoot for 32 F.  They are nice and quiet but not too stressed out.


 That is a local minima that only applies to heavy  colonies  1.7kg  and above comparing it to bees surrounded by air at 15c and according to southwick. That does not mean they consume less stores than at 22c. The local minima may not apply in moving air as found in top entrance hives .  Bees in insulated hives have  been shown to use less stores . But again that is using bottom entrance hives. Quiet might mean desperately trying to conserve energy. Bees evolved with cold winter nests of conductance less than 0.8 w per degree c not 8w per degree c
Title: Re: insulation works - see the result.
Post by: BlueBee on December 16, 2011, 11:26:53 am
Derekm, I believe you mentioned before you protected the edges of your super PU foam hives with fiberglass and resin.  Is my memory correct on that?  If so, how many coats of fiberglass did you use?  How many coats do you think would be necessary to withstand a hive tool prying boxes apart?  Did you end up covering the exterior walls with fiberglass/resin too?
Title: Re: insulation works - see the result.
Post by: derekm on December 16, 2011, 06:23:22 pm
I tried just resin and several coats. This was brittle. A single layer of fibreglass tissue worked but is labour intensive. I went eventually for 2mm correx just on the contacting faces. They dont propolise it!. Under the frame lugs is the ally angle of the frame runners. The outside at the moment has only the alu foil /card coating that the sheets come with. Then an additional coat of resin or paint. Next experiment is 0.5mm ally sheet outer coat as anti woodpecker measures.
Title: Re: insulation works - see the result.
Post by: Sparky on December 16, 2011, 06:24:50 pm
Have you guys noticed any condensation problems in the foam hives without ventilation ?
Title: Re: insulation works - see the result.
Post by: BlueBee on December 16, 2011, 08:08:20 pm
Thanks for clarifying your edge protection scheme.  I’ve been thinking about making a new foam design this winter to replace some of my “foam shell” designs and have been pondering how to deal with the edges and wood peckers.

Actually I’m more concerned about a skunk clawing into my bare foam sides than I am about wood peckers, although there are a lot of wood peckers around here too!  Probably only a matter of time before something digs into them.  So I’ve been pondering how to give my designs more mechanical protection.

I figured fiberglass + resin would be very labor intensive.  Making my nucs was labor intensive enough as it was!  I don’t want to make these things anymore difficult to build than they already are   :)

I think what you call correx is what we call coroplast over here.  What type of glue adheres good to that stuff?  Could you use that for your side protection instead of metal?

You mentioned “0.5mm ally sheet”, I assume this is some metal alloy or aluminum?  They sell fairly thin roof flashing here at our big home improvement stores, but it still looks a bit cumbersome to work with.  It might be thicker than 0.5mm, I don’t know for sure.  How do you attach metal to foam?  Contact cement? 
Title: Re: insulation works - see the result.
Post by: BlueBee on December 16, 2011, 08:35:35 pm
Sparky, my foam hives use top ventilation, so I’ll have to pass on answering your original question.

I can report this though.   One of my foam hive designs is getting wet; my 8 frame nucs with a 3mm x 12mm top vent.  I’m pondering what to do about that now, if anything.  

My full sized foam insulated hives are based on a different design; they have a traditional wood hive inside of a foam shell, they all appeared dry under the wood tops.  However the bees are also still low in those boxes too; that may have some effect on lid condensation, I don’t know.  
Title: Re: insulation works - see the result.
Post by: derekm on December 17, 2011, 08:07:50 am
Have you guys noticed any condensation problems in the foam hives without ventilation ?
No condensation at all - so far
the two hives one has a plastic mesh floor(its a commercial polystyrene brood box with a polyurethane super and roof) the other(a full on polyurethane with  tall floor section having set of narrow slots that channel the debris out and inclined tunnel entrance.
Title: Re: insulation works - see the result.
Post by: derekm on December 17, 2011, 08:14:49 am
..

I think what you call correx is what we call coroplast over here.  What type of glue adheres good to that stuff?  Could you use that for your side protection instead of metal?

You mentioned “0.5mm ally sheet”, I assume this is some metal alloy or aluminum?  They sell fairly thin roof flashing here at our big home improvement stores, but it still looks a bit cumbersome to work with.  It might be thicker than 0.5mm, I don’t know for sure.  How do you attach metal to foam?  Contact cement? 

Correx is polyproplene. Very difficult to glue to. I've used epoxy resin. Ally is UK slang for Aluminium.  metal to PU foam is contact adhesive.
Using the correx as side protection was a plan hence my house quite a few sheets of correx ready to do just this, however the correx can easily get water inside itself if you dont seal the end properly and then you get algae growing. 
Title: Re: insulation works - see the result.
Post by: BlueBee on December 17, 2011, 09:06:52 am
LOL, good point about Algae!  I hadn’t thought about that.  There’s always something.....

I WAS thinking of extending a lip on the top and bottom of a hive body and then gluing the correx stuff on the sides with the overhanging lip shielding the top and bottom corrugations.  Then a coat of caulk in the gaps to seal everything up.  However I’m not a huge fan of caulking and all the caulk I buy seems to shrink to about 50% its initial size.  I’m also afraid the edges between wall panels would turn out real messy.  I like the idea of using some kind of wrap instead.

I saw some polymer roofing underlayment at a hardware store that caught my eye for possible side protection.   Stuff comes in rolls that are 100’ long x 4’ wide.  It appeared to be very scratch proof, but I haven’t bought any yet.  Here’s a link to a version DuPont makes.  The stuff I saw was gray in color so it wasn’t exactly the same product as described here:  http://www2.dupont.com/Tyvek_Weatherization/en_US/products/residential/resi_roofliner.html (http://www2.dupont.com/Tyvek_Weatherization/en_US/products/residential/resi_roofliner.html)

I do like the idea of wrapping some material around the foam for protection because the wrapping technique eliminates the need to treat the edges between walls.
Title: Re: insulation works - see the result.
Post by: Vance G on December 18, 2011, 10:31:27 pm
Do you think this product would make a good hive wrap as is?   How expensive is it?
Title: Re: insulation works - see the result.
Post by: BlueBee on December 19, 2011, 05:41:50 am
That’s a good question Vance.  I assume you mean a good hive wrap for wood hives?  I don’t know, I hadn’t thought about that.  It might.  The stuff I saw was at a local lumber chain here in Michigan called Self Serve Lumber.  I haven’t noticed it for sale at the national big box stores, but then again I haven’t looked real closely.  I believe the price was about $50 for a 100’ roll.

I figure I could protect about 42 of my jumbo sized foam brood bodies with a roll of the stuff so the cost would be about $1.20 per box to wrap/protect.  So far that is cheaper than the alternatives I’ve stumbled across if I can get it to stick to foam and if I can get paint to stick to it.  These two things I do not know.
Title: Re: insulation works - see the result.
Post by: derekm on December 22, 2011, 10:53:25 am
 i will repeat the experiment with supers and varing size of top vents over the holidays
Title: Re: insulation works - see the result.
Post by: BlueBee on December 22, 2011, 03:16:53 pm
i will repeat the experiment with supers and varing size of top vents over the holidays

Now THAT will be interesting to see!  Close off that bottom vent, give them a little top venting, and let’s see what you find!