The half rule of insulaton

[@etiennetardif]

The chart in the video represents the potential impact of insulation. By adding a couple R-value and (reducing top venting - not necessarily removing) will cut heat loss by 50-60%. This will lower your effective clustering temperature. Typically non-insulated colonies will cluster 10C (50F), as you add insulation this temperature drops. Clustering is about heat and energy conservation, bees know when to switch. My measured clustering temperature is around -15 to -20C. Clustering is a cold stress response by the bees. I will release a few more videos going through these principles. Here is a talk I did for our Nordic friends last year - kzbin.info/www/bejne/hoqXgGeDYqeibNUsi=3esqNFuK2H_ceYUL

[@KobeApiaries]

Great content and data as always! Thank you for continuing to help educate on the advantages of insulation vs ventilation.

[@normanboyd]

Keeping bees here in Texas on the Gulf of Mexico coast. I do the same thing: insulate the top year round. We don't get near as cold but good insulation saves food.

[@Taz3434]

An app for overwintering bees?! Amazing! I share your videos to many new beekeepers in hope theyll watch 15mins of the 2hrs. An app would be incredible to share!

[@etiennetardif]

Here is a link. The next one I will attempt to make is to model top entrances size vs bottom entrance. www.northof60beekeeping.com/north-of-60-research-projects/bee-apps

[@MarcvanKralingen-d1z]

First year beekeeper here outside of Ottawa, one hive with plans for more next year, followed many of your practices and suggestions, hoping they survive my first winter. Really appreciate and look forward to your videos!

[@MinnesotaBeekeeper]

Etienne we adhered reflectic foil survival blankets to the bottoms of all our pink insulated top panels. Used 3M fabric adhesive. Tried others, not as affective. Supposedly it prevents the infrared from even getting to the insulation. Just a thought.

[@etiennetardif]

It will protect your styrofoam and prevent the UV from breaking it down. Paint will do the same and hence why it is recommended that folks paint their polys.

[@jasonseaward8506]

You are such a smart individual. I think i overdid my insulation as my lowest I'll see is maybe -20 or -15°c and I have 17.5R plus the telescoping outer cover, and reflectix inner so i think I'm around 20-21R on top and 7.5 on the sides but I'm a first year beekeeper with 2 hives that i feel are smallish. We normally hang around the freezing mark but usually very wet so I'm hoping this condensing hive helps. I feel confident in the science so thats the reason i went this way.

[@etiennetardif]

In general I am not too worried with too much... Your setup seems great for me!!

[@jasonseaward8506]

@etiennetardif6552 thank you, as it's my 1st year, I only have 2 colonies, they were kinda smallish (only 10 frames in ea colony, one I did 5over5 BC it was a little smaller) I was just thinking of the law of diminishing returns that you had mentioned, but it's only one layer of this foam insulation that has foil on both sides. My goal is to reach at least 1500 colonies so these colonies are probably the most important colonies out all colonies to come lol. Thank you for your tip as well as your reply as I know you are a super busy individual. I couldn't help but giggle when I saw u wearing the snowmobile mitts to do beekeeping chores lol.

[@etiennetardif]

As I type this my battery is now back up to 65% up from a low of 35%. Hive monitoring north of 60 requires one to be creative!!

[@emindeboer5280]

Etienne, is it really that your Q single colony/hive is powering out 125Ws on R1? or is it estimated? c 10Ws on ~R8(?) is reasonable: then your cluster is fluffy, not tight, right? How to calculate this chart, or was it created on top of measured data? How to know what Ws my colony is buzzing out at R1 (2 cm Wood) at say 0°C outside?

[@emindeboer5280]

Etienne: what about water and thirst? you have this colder bottom space in your hives. how do you collect the water? what temp does this water reservoir has inside the hive? I take this from German publication: air circulation inside a wooden trunk hive is sufficient to control heat/hygro/co2 without exchange over entrance hole - so to retain energy: but this requires condensation inside the hive at the bottom and water resource for the bees to collect without need to fly out and possible die in the cold.

[@emindeboer5280]

And: we got this concept of honey stores above winter cluster being a heat storage - dampening the amplitude of daily temp change from outside to inside smoothing out temp stress. so we have the horizontal-colony-expansion method in winterprep in langstroth hives - and only in summer utilize the vertical-col-expans method for harvesting while in natiure is vertical situation all year.

[@etiennetardif]

Here is my full presentation on thermodynamics that I put out last year. kzbin.info/www/bejne/hoqXgGeDYqeibNUsi=A5_o0Co8lUdRx-DB

[@etiennetardif]

Fully agree, if the hive shell cannot retain any heat, the bees will be cluster driven vs enclosure driven. At higher R-Value the honey bee colony is enclosure driven where the bees behaviour uses the enclosure to survive vs the last defence of the bee cluster. In the enclosure driven more of bees are exposed to the natural humidity (metabolic respiration), higher CO2 levels (ULMR) and are more free to move around. In this looser configuration natural convective current will carry warmth and heat across the honey frames (thermal mass) and help reduce losses. Condensation occurs on the outer walls (condensing walls) which will release the latent heat back into the internal air. This article is due for an update as this was 4 years ago, but most of it is still relevant. It shows the extent of monitoring that I have done. I have since added CO2 and O2 as well as continued to refine my model. www.northof60beekeeping.com/north-of-60-research-projects/winter-2020-monitoring

[@LittleRiverBees-or6qp]

On the top I have 2 inches of Foam Board, so the setup on top is a sealed inner cover, the foam board and the telescoping cover sitting on Top of the foam board. That gives me 2 dead air spaces in addition to the foam board. The sides have 2 inch foam boards down almost to the bottom board. During the heat of the summer I had zero bearding on my biggest hive.

[@etiennetardif]

got balance cost and time when determining the bast approach. For me at 4 to 12 hives at the most it is very manageable. I use polys so I get a base R7.

[@aaronparis4714]

Have a good Christmas my friend

[@etiennetardif]

Thank you... same to you

[@sbgmimedia]

Good Stuff - Thanks Etienne!

[@duanearmitage-pv5cu]

Wow. Great information again. Im looking forward to listening to you again in kentucky. I use 4" of foam on top in wisconsin

[@etiennetardif]

Thanks, see you in Kentucky! I will be giving the microscopy workshop this year... we will run 3-4 90min workshops. In between I will be floating around!!

[@Kuehlschraenk]

Keep the humidity in mind. Trapping the humidity might influse the apparent temperature and can cause condensation which is a energy loss.

[@etiennetardif]

condensing vapour will re-release the energy (latent heat). When using a single entrance all incoming air comes into contact with outgoing air thus allowing some heat exchange (pre-heating). Top venting, vents out moist air (no potential to re-release latent heat) and eliminating the heat exchange at the single entrance. At -40C all moisture is critical for the bees to survive. Cold air has very little moisture content. All internal hive water comes from the bees metabolic processes.

[@Kuehlschraenk]

@@etiennetardif Thanks for your answer. The concept is a bit hard to grasp for me. In Germany (where relative humidity is most of the time around 85% at about 4°C), there is increased popularity to use supers with semi-permeable membranes (like those used for roofs). These membranes allow excess water vapor to escape through the top and move the dew point outside of the hive into the super. Apparently, this results in an increased temperature within the hive. What do you think about that? For more context, there is often excess water in hives, which results in mold. I have an apiary where there is constantly a small puddle of water on the screened bottom board.

[@KobeApiaries]

@@Kuehlschraenk As water condenses, heat is released (latent heat). So, you would be better off insulating the cover and allowing the condensation to occur on the sides and near the entrance (below the cluster). Not only will you mitigate the risk of water condensing and dripping onto the cluster, but you still get to utilize the heat given off by latent heat.

[@Kuehlschraenk]

​@@KobeApiaries Ok, got it, thanks! So, bottom line: you should see an increase in food consumption if bees overwinter in dry conditions since there is no latent heat working in their favor. I asked ChatGPT about the math, and the energy released by condensation is much greater than I thought. Are there estimated how much condensation actually occurs and how much latent heat is released? I.e. over the winter, is the latent heat greater than the energy reduction to heat a dry room.

[@KobeApiaries]

​@@Kuehlschraenk In order to have a "dry" hive, you would have to ventilate it. If you are venting the hive, then you are also releasing the heat. The heat loss due to ventilation is the main reason why the bees are going to go through more resources. Think about your furnace use if you left the windows open upstairs during the winter. You can definitely do the math of the latent heat calculation if you know values to all of the variables, but it would be pretty complex. Variables that you would need to consider: - Size of the colony - External temperature / dew point - Internal surface area - Insulated value of your hive setup - Rate of respiration In saying all of that, you don't need to make it complex. Just know that the more insulate, the better it is for your bees. This is true 365 days a year in any climate.

[@MikeChamplin]

In general, how does all this thermal logic change with upper ventilation? negligible or significant....

[@etiennetardif]

Qheat_loss = 1/R x A x (To-Ti) + "Top Vent" + Box Leakage + Lower Entrance -- Changes the air flow and induces a stack effect. If the Top entrance is too large it will negate the impact of the insulation. I just finished part one of an online calculator, I'll post it tomorrow. I will create a similar one to estimate heat loss through a top entrance. It will also vent out the CO2 which the bees are adapted to use to reduce their metabolic rate.

[@mikehill9888]

Does higher CO2 levels give the hive a benefit?

[@etiennetardif]

CO2 is good and required to effectively overwinter. The key is a larger bottom entrance when not using a top vent. Make sure you have some wind protection to prevent direct wind. kzbin.info/www/bejne/q6a7omZ-e79mmNE

[@framcesmoore]

This was great, I have insulated my tops 2 in at least, think it is r10 I have 1 more oa treatment than I am using bee cozies with no vent on the top i I am in Virginia Your thoughts please and thanks I hope your bees do good. I have seen your videos for a while and I think you know what u are doing. Be for u do all the wrapping do u treat your bees with oa. Have a Blessed week

[@etiennetardif]

typically treat with OA yes in mid August (my fall). On your setup, make sure you don't restrict the lower entrance, mouse guard only if you have those in your area.

[@framcesmoore]

@@etiennetardif thanks

[@aaronparis4714]

Smart cat 👍🏾👍🏾👍🏾🐝🐝🐝

[@BlanchardsBees]

Oh boy that even looks cold 🥶 brrr

[@etiennetardif]

I wouldn't live anywhere else!!

[@emindeboer5280]

Etienne: thanx :) Have you thought about putting your hives under ground - like in a kind of bunker? Like beekeepers do it in Russia, Ukraine..

[@emindeboer5280]

yeah : it helps to estimate c 1-2 m³ of surface of a typical hive in overwinter setup. But? what insulation is too much? like figuere in the threshhold of a clusters 24/7 base metabolism like c 5Wattts? can this 5 Watts overheat a to much insulated hive? Only entrance hole left for heat exchange.

[@emindeboer5280]

R-value (U.S. customary units) = ​RSI (metric) ⋅ 5.678 ​RSI = R-value ÷ 5.678

[@etiennetardif]

Remember higher CO2 will lower the metabolic rate even more. It is rapid temperature fluctuations that can cause some issues. My ground is frozen 12ft here so it will have a chilling effect that helps keep the bees cool during these extreme events.

[@etiennetardif]

Too much work... I get good wintering outside with minimal effort

[@russellkoopman3004]

Batteries in your stupid cold weather will need all the help they can get. LOL Here in MN I use 2" of styrofoam and it seems to work well.

[@etiennetardif]

The bees offered their extra heat for this!!