Author Topic: 0c 32f outside 18c inside at floor should i be worried? (Read 17166 times)

derekm · « **Reply #40 on:** November 20, 2011, 02:04:45 pm »

Both hives now have PU feeding eckes (shims?) with perspex (lexan?) bottom boards and topboards.. so I can see how much fondant (candy?) they have eaten without cooling the hive too much. I can also how they are moving about. In addition they are both now permanently on bathroom scales...
The hives are still acting ... the same as before. We are still getting a few warm days highs of 15c. If the day is bright they fly at around 8c, dull they dont bother at all.

rdy-b · « **Reply #41 on:** November 20, 2011, 06:49:25 pm »

sounds like quite a learning opportunity -can you post pics--RDY-B

BlueBee · « **Reply #42 on:** November 20, 2011, 07:09:07 pm »

My nucs are now in cluster. We go weeks or months at a time here without sunshine so not much chance of a solar gain or flying. My golden summer glow is starting to turn into a ghost glow :shock:

So bathroom scales? Are you using mechanical type scales or electronic?

I’m going to try to make some load cell based hive scales this winter. Probably going to go with 10lbs load cells and some low offset, low noise, fixed gain Analog Devices amps. Maybe the AD8293G80. Boost the tiny signal from the load cell with an absolute minimum amount of error and then feed that into the ADC port of a Micro.

derekm · « **Reply #43 on:** November 21, 2011, 03:32:41 pm »

I would close that top vent of yours until you get 18C inside The scales are mechanical left over from my racing car days. Load cells are cheap on ebay, and so are the op amp to construct the instrumentation amplifier

BlueBee · « **Reply #44 on:** November 21, 2011, 07:37:46 pm »

To be honest, I was a little surprised to find it 56F/13C inside the nuc with them clustered. We had been having cool nights with mean 24 hour temps about 0C/32F with no solar gains. I would have to conclude that the bees are simply not making many watts of power at 56F. If they don’t feel the need to generate more heat, the temperature inside the hive isn’t going to increase.

Low heat generation = low honey consumption = good!

My top vents are about 3mm x 15mm; not very big. The Sun FINALLY made an appearance today and I did see some bees flying in low 40s.

Quote from: derekm on November 21, 2011, 03:32:41 pm

Load cells are cheap on ebay, and so are the op amp to construct the instrumentation amplifier

So are you going to make a hive scale from some?

derekm · « **Reply #45 on:** November 22, 2011, 05:47:21 pm »

Take one of your nucs and put inside a 20W 12V light bulb. Connect the bulb up to a variable power supply measure how much heat it takes to get it various parts of the nuc/hive to 18C and 34c with both the vents open and closed. i m going to try this experiment my self

derekm · « **Reply #46 on:** December 05, 2011, 06:45:47 am »

14.6C today outside -2C

BlueBee · « **Reply #47 on:** December 05, 2011, 10:26:03 pm »

Sounds like you might need some more insulation :-D

What do you think the temperature is going to settle out at over winter?

derekm · « **Reply #48 on:** December 06, 2011, 09:42:15 am »

got an issue with the cold junction temperature compensation in the instruments I'm using. Taking a warm meter outside in to the freezing cold is giving strange results.

derekm · « **Reply #49 on:** December 10, 2011, 03:58:41 pm »

From keeping the floor at 18c at below zero they have gone down to 7c with the outside at 5c. They are sending out periodically bees.for some reason they have abruptly changed behavouir.but they are still moving around on the top. Its like they just decided to turn the downstairs heating off to save fuel. Remember this hive is well within their thermal control range for this ambient temp...they could easily have the entire hive at 34c.

BlueBee · « **Reply #50 on:** December 10, 2011, 04:49:54 pm »

OK, so why did they turn the heaters off?

All the way down to 7C (44F), that surprises me a little. Is that 7C measured at the bottom of your super PU hive?

BlueBee · « **Reply #51 on:** December 10, 2011, 06:04:02 pm »

OK, I just froze my butt off checking my hives. I had to pry the top off the PV=nRT nuc, it was frozen solid to the hive. We’ve been below 32F (0C) for quite some time now. My little IR thermometer read 28F outside (-2C) the hive and 55F inside the hive. As you can see from my earlier post, the bees really haven’t moved much.

My full sized super insulated hives with top entrances (9mm x 25mm) were reading 50 to 55F at the top entrances.

Like you, my foam hives have the insulation capability to be much warmer than they are. I think it comes down to the temperature at which bees cluster. Below that temperature they are going to cluster and make some heat, above that temperature they break cluster and don’t generate heat. That being the case, I’m not expecting my hives to get above 60F/16C the rest of the winter unless there is some solar gain or until they start brooding. Once they start brooding, they should be making heat all the time and that’s when all the insulation will start bumping the inside temps into the 70s or 80s.

derekm · « **Reply #52 on:** December 11, 2011, 01:32:10 pm »

Quote from: BlueBee on December 10, 2011, 04:49:54 pm

OK, so why did they turn the heaters off?

All the way down to 7C (44F), that surprises me a little. Is that 7C measured at the bottom of your super PU hive?

Yes the 7C at the bottom of the super PU hive. They are running around at the top in the warm at above 18c. Why? I have guesses.
but no knowledge. there is now very little flying during the day, the scouts, which are still going out, turning up nothing worth rousing the colony for . The gorse is in bloom but that will give only pollen (particulary if cold). My conjecture is that if there is nothing worth flying for and the days are very short (its 50N here), they cluster to conserve energy but not for the purpose of keeping warm. They are still warm bees just in "energy conservation" or just bored.
Studies have shown that bees can cluster because they "like" being together. They dont need a thermal imperative.

The PU hive will expose their behaviour minus the thermal imperatives ( keeping the hive floor at 18 above ambient for weeks then letting it fall to ambient).. understanding it is another matter...

BlueBee · « **Reply #53 on:** December 16, 2011, 11:34:07 am »

Have you checked for condensation in your super PU hives this winter?

We had a brief warmup above freezing yesterday. Got up to 10C/50F. I went out to check up on the bees. There were out flying even though it was cloudy and windy. They were hauling out some dead and making cleansing flights.

My hives with top entrances were nice and dry, but my nucs with bottom entrances and only small top vents (3mm x 12mm) had a good deal of condensation under their tops. In fact there was black mold starting to grow on the underside of the foam top cover! Mold will grow anywhere won't it!

windfall · « **Reply #54 on:** December 16, 2011, 01:03:41 pm »

Bluebee,

I like your screened tops for the reasons you have pointed out yourself. But this was one of my concerns in their use. It creates a space "inside" the hive that the bees cannot coat in propolis, or clean, and perhaps more important they cannot access condensation to "drink it" as many have reported they do.

Is that space the only place you are seeing condensation in the insulated nucs?

I should have taken the last warm window a week ago to peek in mine, but....well....

BlueBee · « **Reply #55 on:** December 16, 2011, 01:34:48 pm »

Good point windfall! My foam design will probably need a little tweaking for next year.

Actually the undersides of my foam tops (on the nucs) were dripping like a monsoon! Well…maybe not quite that much…but there was a lot of water. Far more than the bees could drink IMO. We did have monsoonish rains for a few days, but I don’t think the rain was the source of the condensation.

I took a roll of paper towel out of soaked up as much as I could. Of course plenty of water dripped on the frames. The bees didn’t go running toward the water for a mid winter drink so I don’t think they were too thirsty! The only place I saw condensation in the nucs was on the underside of my foam tops.

Not sure what action I’ll take, if any. Maybe I need to open my top vents a little? The bees all looked good.

Didn’t see any condensation problems in my foam hives with a top entrance.

derekm · « **Reply #56 on:** December 16, 2011, 02:47:22 pm »

Quote from: BlueBee on December 16, 2011, 11:34:07 am

Have you checked for condensation in your super PU hives this winter?

We had a brief warmup above freezing yesterday. Got up to 10C/50F. I went out to check up on the bees. There were out flying even though it was cloudy and windy. They were hauling out some dead and making cleansing flights.

My hives with top entrances were nice and dry, but my nucs with bottom entrances and only small top vents (3mm x 12mm) had a good deal of condensation under their tops. In fact there was black mold starting to grow on the underside of the foam top cover! Mold will grow anywhere won't it!

condensation? none at all .... And it has been cold and wet.
I suspect that the your small vents show the problem that the small vents are cooling the air just inside the hive.

BlueBee · « **Reply #57 on:** December 16, 2011, 04:12:59 pm »

I can’t disagree with your logic about the top vent cooling the top surface below the dew point. That sounds very plausible to me. However I’m still not convinced of the best design for a super insulated hive yet. I have run designs with top entrances and others with bottom entrances this year and so far I’ve had more problems with the bottom entrance designs. I’m waiting until spring to see what else might go wrong in the top vs bottom debate before picking a winner for my bee yard.

So if you’re not seeing condensation on the top of your super PU hive, are you seeing it along the sides or bottom? The bees are exhausting water vapor to live and make heat, it has to go someplace.

derekm · « **Reply #58 on:** December 16, 2011, 06:05:27 pm »

in doing condensation investigations the bees dont help in a warm hive cos they drink the water (they are still running around). However because I have a clear plastic loose inner cover I prevent the bees drinking from the lid, the sides is another matter. I know there is no top condensation and There is no evidence of condensation on the sides but...

derekm · « **Reply #59 on:** December 17, 2011, 08:21:24 am »

looked inside both hives - the bees have clustered away from temperature probes(typical!). in the full on PU hive they are next to roof in the middle (no super), with quite a few bees walking around on the top. in the polystyrene/PU hybrid they are still in the brood box with only the odd bee moving about.