Oh No! Not Matchsticks Again?

[boywonder]

⬆❤........100% agree with what that man said....INSULATION not VENTILATION

I'm sorry, but I find that kind of comment ignorant.

Ventilation is absolutely vital, both as an exhaust for the CO2 in the hive, and as a means of regulating condensation. Note I say "regulate", as, whilst at a certain level it is surely benign (and, in some regards possibly even beneficial - e.g. as a source of water, and doffing my cap in the general direction of the aforementioned research on the effects on varroa), at high levels, it must surely have a deleterious effect on the wellbeing of the colony.

I suspect that many of those who froth at the mouth on the subject of matchsticks would also agree that bees tolerate cold, but don't tolerate damp so well. Not wanting to anthropomorphise, or draw inappropriate parallels, but I live in a highly insulated, triple glazed house with high levels of airtightness. I have a mechanical ventilation system designed to deliver the right level of air change in the right way. If I did not have that ventilation, I would become sick (or asphyxiate) and there would be mould appearing all over the shop.

I should really take a closer look at Derek Mitchell's research; particularly to help me understand how the air moves around the hive under certain conditions.... but this is surely NOT a case of, "Insulation not Ventilation", but rather "Insulation AND APPROPRIATE Ventilation" ?!

I am NOT advocating matchsticks. However, good luck to those who want to do this - as long as they do so in the knowledge they are creating a chimney which will vector precious warmth up and out. I personally find (as also stated earlier in this thread) an OMF and reduced entrance seems to work for my bees. I insulate my roofs, and the insulation blocks the designed-in vents in the roof. That said, I don't hermatically seal the crown board. Indeed, in most, I leave an old porter bee escape in situ, through which some air (and heat) inevitably trickles into the roofspace. My bees overwiter well, and it all feels nicely balanced. Incidentally, in that setup, I have very little condensation (certainly nothing excessive), and I for one feel happy about that.

I just tend to think the ventilation point is a bit more nuanced than some think.

 

[user 20297]

I'm sorry, but I find that kind of comment ignorant.

I just tend to think the ventilation point is a bit more nuanced than some think.

I'm not sorry, but I find your kind of comment a little bit presumptuous. I am not ignorant of basic science. Although I am relatively new to beekeeping, I am reasonably well-versed in those practical aspects of it which are transferrable from the real world, outside beekeeping.

Everything is more nuanced than some people think, and in a "virtual" "high-five", such as the one I made and in which I appear to have offended you so much, nuance is not the order of the day.

If CO2 and condensation were going to kill my bees this winter, they would already be long gone. Despite them being cossetted in thick layers of insulation, both above and around and having the inspection boards in place for most of the winter, somehow, they have managed to survive. They have endured other hardships forced upon them by my somewhat maverick approach, but I don't wish to garner more disdain by airing them here.

It's back to the common theme of beekeeping; we all do what seems to work for us, but the bees get on with it without sneering at our inadequate understanding of their strategies.

 

[user 6228]

"bees tolerate cold, but don't tolerate damp so well."
Classic bee lore and full of anthropomorphism, ambiguity and confusion. Bees live an environment with much higher CO2, water vapour and temperature than humans. They come equipped with apparatus for forced advection and the sensors to drive it for Co2 and water vapour. Comfort for an adult honeybee is 75% RH at 34C , thats nearly 3 times the water content than the 50%RH at 20C that we might find comfortable. We associate mould on walls with low temperatures discomfort and illness, yet we eat cheese. We associate condensation with temperatures dangerously low to us e.g . we encounter condensation at 9C surfaces from 50%RH at 20C. Honey bees at 75%RH at 34C will encounter condensation on surfaces close to 29C which is 11degrees above the temp bees need to start thorax activity.
The classic ventilation of hive is to remove water condensing on surfaces at around 7C. The problem bee have with condensation is not that its water, but that the water is at 7C and is falling on them. The solution is to make the water 29C not to remove it. Bees need water all year round, yet post war wooden hives are a desiccator/dehumidifier. The high heat loss side drops the water content of the air the same way a refrigerators does drying out that piece of cheese you left uncovered, The wooden hive drops the water content of the air to 1/4 of that the honey bees find comfortable.

Honey bees have a high tolerance for Co2, in fact they kill hornets when they ball them with a combination of Co2 and heat. The heat alone the hornets dont mind.

Appropiate ventilation is a hole ~ 12 sq cm at the bottom of the hive. becuase that is what they chose for themselves

References for the above available on request.

 

[Apiarisnt]

"bees tolerate cold, but don't tolerate damp so well."
Classic bee lore and full of anthropomorphism, ambiguity and confusion. Bees live an environment with much higher CO2, water vapour and temperature than humans. They come equipped with apparatus for forced advection and the sensors to drive it for Co2 and water vapour. Comfort for an adult honeybee is 75% RH at 34C , thats nearly 3 times the water content than the 50%RH at 20C that we might find comfortable. We associate mould on walls with low temperatures discomfort and illness, yet we eat cheese. We associate condensation with temperatures dangerously low to us e.g . we encounter condensation at 9C surfaces from 50%RH at 20C. Honey bees at 75%RH at 34C will encounter condensation on surfaces close to 29C which is 11degrees above the temp bees need to start thorax activity.
The classic ventilation of hive is to remove water condensing on surfaces at around 7C. The problem bee have with condensation is not that its water, but that the water is at 7C and is falling on them. The solution is to make the water 29C not to remove it. Bees need water all year round, yet post war wooden hives are a desiccator/dehumidifier. The high heat loss side drops the water content of the air the same way a refrigerators does drying out that piece of cheese you left uncovered, The wooden hive drops the water content of the air to 1/4 of that the honey bees find comfortable.

Honey bees have a high tolerance for Co2, in fact they kill hornets when they ball them with a combination of Co2 and heat. The heat alone the hornets dont mind.

Appropiate ventilation is a hole ~ 12 sq cm at the bottom of the hive. becuase that is what they chose for themselves

References for the above available on request.

Careful, Derek. You are bringing facts and evidence into the argument. That will never do...

 

[pargyle]

"bees tolerate cold, but don't tolerate damp so well."
Classic bee lore and full of anthropomorphism, ambiguity and confusion. Bees live an environment with much higher CO2, water vapour and temperature than humans. They come equipped with apparatus for forced advection and the sensors to drive it for Co2 and water vapour. Comfort for an adult honeybee is 75% RH at 34C , thats nearly 3 times the water content than the 50%RH at 20C that we might find comfortable. We associate mould on walls with low temperatures discomfort and illness, yet we eat cheese. We associate condensation with temperatures dangerously low to us e.g . we encounter condensation at 9C surfaces from 50%RH at 20C. Honey bees at 75%RH at 34C will encounter condensation on surfaces close to 29C which is 11degrees above the temp bees need to start thorax activity.
The classic ventilation of hive is to remove water condensing on surfaces at around 7C. The problem bee have with condensation is not that its water, but that the water is at 7C and is falling on them. The solution is to make the water 29C not to remove it. Bees need water all year round, yet post war wooden hives are a desiccator/dehumidifier. The high heat loss side drops the water content of the air the same way a refrigerators does drying out that piece of cheese you left uncovered, The wooden hive drops the water content of the air to 1/4 of that the honey bees find comfortable.

Honey bees have a high tolerance for Co2, in fact they kill hornets when they ball them with a combination of Co2 and heat. The heat alone the hornets dont mind.

Appropiate ventilation is a hole ~ 12 sq cm at the bottom of the hive. becuase that is what they chose for themselves

References for the above available on request.

Really great explanation and information ... what you didn't say ~ and there is also some evidence for ~ is that the Varroa reproductive cycle is hindered by high humidity and temperatures in the hive. I've proved to my own satisfaction that providing conditions where the bees are readily able to maintain as near to their ideal hive temp and humidity as possible helps with them managing varroa, leads to less disease and less colony stress. It's what I aim for in my hives .... works for me and the bees.

 

[madasafish]

I have 4 mini nucs - two boxes. The ONLY ventilation is a very small entrance - one beespace.(the bottom ones have been sealed with gaffer tape)
The bees in them have survived all winter. They are heavily protected from wind and rain with an outside cover with 50mm insulation on the roof.

My main hives have no ventilation as they are on solid floors/blocked OMF with a three beespace wide entrance..

If ventilation is an issue in hives, they should all have died.

(see also feral colonies in trees)

I just love it when an argument is made in complete contradiction of real world experience and with ZERO - like 0 - evidence of any attempt to produce any statistics or - heaven forbid - airflow calculations. The scientific method has obviosly been neglected in UK schooling .

Apologies for the rant.

 

[Murox]

Would that be an intellectual rant (the obvious, the evident) or an empirical rant (proofs).

 

[Malmcd]

I do not believe that sufficient credit is being given to the bees’ ability to adapt to the conditions they find themselves in! My father kept bees in hives with enormous amounts of top insulation, cavity walls with insulation packed down and a small bottom entrance. WBCs of course. They wintered well. When I started beekeeping I kept bees in nationals with full width entrances, open feedhole and matchsticks. (Solid floor as OMFs had not been invented!) They wintered well. Since then I have used various combinations of solid floors , OMFs, top ventilation, no ventilation, poly brood boxes, top insulation and no insulation, plus WBCs. They all wintered well.
I cannot say that any have proved noticeably better than others. What has made a difference however has been the quality of the queen and health and strength of the colony going into winter.The bees seem to be able to cope with all environmental conditions thrown at them!

 

[madasafish]

Would that be an intellectual rant (the obvious, the evident) or an empirical rant (proofs).

As no proofs were given, an intellectual one.

 

[Erichalfbee]

As RAB is fond of saying, if you must put matchsticks in a hive with a solid floor put them between the floor and the box sitting on it.

 

[Sayle]

If CO2 and condensation were going to kill my bees this winter, they would already be long gone. Despite them being cossetted in thick layers of insulation, both above and around and having the inspection boards in place for most of the winter, somehow, they have managed to survive. They have endured other hardships forced upon them by my somewhat maverick approach, but I don't wish to garner more disdain by airing them here.

I'd certainly be interested in what your insulation is! One thing that I've noticed a lot of people saying that they are using (or would use given the chance) is kingspan/celotex, but something that I don't see mentioned at all is the major disadvantage of this: polyisocyanurate (the chemical the celotex foam is made from) begins to rapidly lose its insulative performance when the temperature drops below 15C! When you want your bees to be at their most comfortable and toasty compared to the outside is when celotex is performing at its worse. Compare this to something like plain-old sheep wool which works fine at whatever temperature (and if it gets wet it can dry out: bonus!).

In terms of insulation though, the girls went through this winter with 50mm of wool in the walls and floor (it's a DIY hive, timber interior and marine ply exterior), and as many layers as I could get in the top given that trees provide effectively infinite vertical insulation and that's where 75% of the heat goes.

As an interesting aside, the DIY hive uses a solid floor - about six inches below the mesh. Varroa can't climb back up (or at least most of them don't, though don't ask me to hunt down the paper in question) after falling more than a few inches and it also prevents humidity and temperature losses through the bottom. I never saw any condensation on the (transparent) coverboard when I checked during winter, though opening the inspection tray space below the mesh showed plenty of water was circulating since the floor was wet. Presumably it all condensed on the colder walls where the bees could use that lukewarm water for whatever they liked.

Sorry, something of a tangent there. But yes, the idea that the bees would kill themselves with hypoxia (?!!) because of no ventilation is rather strange. They have an entrance to provide fresh air.

 

[Erichalfbee]

I'd certainly be interested in what your insulation is! One thing that I've noticed a lot of people saying that they are using (or would use given the chance) is kingspan/celotex, but something that I don't see mentioned at all is the major disadvantage of this: polyisocyanurate (the chemical the celotex foam is made from) begins to rapidly lose its insulative performance when the temperature drops below 15C! When you want your bees to be at their most comfortable and toasty compared to the outside is when celotex is performing at its worse. Compare this to something like plain-old sheep wool which works fine at whatever temperature (and if it gets wet it can dry out: bonus!).

In terms of insulation though, the girls went through this winter with 50mm of wool in the walls and floor (it's a DIY hive, timber interior and marine ply exterior), and as many layers as I could get in the top given that trees provide effectively infinite vertical insulation and that's where 75% of the heat goes.

As an interesting aside, the DIY hive uses a solid floor - about six inches below the mesh. Varroa can't climb back up (or at least most of them don't, though don't ask me to hunt down the paper in question) after falling more than a few inches and it also prevents humidity and temperature losses through the bottom. I never saw any condensation on the (transparent) coverboard when I checked during winter, though opening the inspection tray space below the mesh showed plenty of water was circulating since the floor was wet. Presumably it all condensed on the colder walls where the bees could use that lukewarm water for whatever they liked.

Sorry, something of a tangent there. But yes, the idea that the bees would kill themselves with hypoxia (?!!) because of no ventilation is rather strange. They have an entrance to provide fresh air.

Are you saying that polyisocyanurate is a poor insulator or that Celotex is? Oh come back Derekm please. Can somebody email him to come rescue us?
Edit.
I had a quick look on internet and celotex etc do suffer a dip in RValue at minus 16.
That’s of no consequence to most of us

 

[Sayle]

Are you saying that polyisocyanurate is a poor insulator or that Celotex is? Oh come back Derekm please. Can somebody email him to come rescue us?

Oh, polyisocyanurate is a great insulator! It's got great performance. Just...when it isn't too cold. Which is fine when it's got a nice thick brick wall between it and the outside and you've got the heat trapped in the house to keep it going. But if you've a thin layer of ply over it (or, god forbid, just strapped it to the side of the hive) you can bet it's flipping cold and not doing the best job it could.

That said, some is better than nothing. It goes from a fantastic insulator to a good insulator, but it's at least still an insulator. It's just the performance loss related to its temperature isn't something I see mentioned when people enthusiastically advocate for it. It's very convenient having a solid board to just slot in rather than something compressible like wool, after all. Cheaper, too!

I'd be thrilled to have someone come in and say that I've misidentified kingspan's PIR boards/celotex as being polyisocyanurate like a numpty, though, don't get me wrong. Or that I'm just wrong about the temperature affecting it in general! My information might be fruit of the poisonous tree. But I'm speaking from my layman's understanding at present.

PS: I should clarify that I'm talking about performance reduction in the 10-20% range, so it's still a decent choice.

PS2: Graph of performance here. It becomes less effective as an insulator quite notably at below the 4C mark. But again, we're not talking a 50% drop or anything here. It's quite 'mild'. But it is a property of the material that exists. I just ended up going for a sheep wool/fibreglass blend that I knew wouldn't degrade with age and could handle moisture just fine. Also means I can put a feeder in the top and just drape the wool blankets over it in the roof space! Obviously I have an Opinion, but I'll certainly not say you shouldn't use Celotex/Kingspan if its the most convenient option. I have the blessing of disposable income and time to tinker with financially sub-optimal hobbyist hive builds. If you're pressed for time or money but still want to insulate, sure, slap some insulation board on the sides and top of the hive. It's better than nothing!

 

[Apiarisnt]

Are you saying that polyisocyanurate is a poor insulator or that Celotex is? Oh come back Derekm please. Can somebody email him to come rescue us?

R value of polyisocyanurate on warm days = 6 per inch
R value of polyisocyanurate on cold days = 4.5 per inch Cold-Weather Performance of Polyisocyanurate - GreenBuildingAdvisor
so PIR does indeed perform less well at low temperatures

but:

R value of sheep's wool = 3.5 to 3.6 per inch Article - Why Consider Natural Wool Insulation? - HealthyHouseInstitute.com - Healthy House Institute

so even at low tmperatures, PIR siginficantly outperforms wool, and that is before considerations such as moisture retention

(BTW Kingspan is made from the same basic material as Celotex ie polyisocyanurate, or PIR)

 

[jenkinsbrynmair]

Oh, polyisocyanurate is a great insulator! It's got great performance. Just...when it isn't too cold.

That's Derek's PhD papers into the shredder then, poor dab

 

[jenkinsbrynmair]

That's Derek's PhD papers into the shredder then, poor dab

R value of sheep's wool = 3.5 to 3.6 per inch Article - Why Consider Natural Wool Insulation? - HealthyHouseInstitute.com - Healthy House Institute
so even at low tmperatures, PIR siginficantly outperforms wool,

But what if you knit the jerseys with a very thick, ribbed pattern?

 

[Erichalfbee]

R value of polyisocyanurate on warm days = 6 per inch
R value of polyisocyanurate on cold days = 4.5 per inch Cold-Weather Performance of Polyisocyanurate - GreenBuildingAdvisor
so PIR does indeed perform less well at low temperatures

but:

R value of sheep's wool = 3.5 to 3.6 per inch Article - Why Consider Natural Wool Insulation? - HealthyHouseInstitute.com - Healthy House Institute

so even at low tmperatures, PIR siginficantly outperforms wool, and that is before considerations such as moisture retention

(BTW Kingspan is made from the same basic material as Celotex ie polyisocyanurate, or PIR)

Thanks for that translation. I had a quick look but got lost in figures I don’t understand. Put a Greek letter on the page and all of it becomes unintelligible.

 

[Apiarisnt]

But what if you knit the jerseys with a very thick, ribbed pattern?

For a moment I wondered why you were so keen to defend the use of sheep's wool, albeit knit one pearl one versions, then I looked again at your location...

 

[Erichalfbee]

For a moment I wondered why you were so keen to defend the use of sheep's wool, albeit knit one pearl one versions, then I looked again at your location...

Now now..... I don’t think he was.

 

[jenkinsbrynmair]

nothing like the feel of wool against the skin..........