The Langstroth Hive
Here in the U.S., the Langstroth hive reigns supreme. Not because it performs well from a bee’s perspective, but because it works well for beekeepers. Its modular design creates almost infinite combinations, and the use of ¾” thick wood stock makes it easy to manufacture pieces and flat pack them for shipping. Beekeepers can assemble the hives with relative ease and maintain them with regular paint or sealant. However, these hives offer basically no protection against temperature changes, expose the bees to large humidity shifts, and leave them incredibly vulnerable to pests.
Where It All Began
I started beekeeping in 2010. However, I have memories of my grandfather’s hives of midnight bees he bought from Sears in the ‘80s and used to supply chunk comb for Thanksgiving meals. He kept bees in a large back yard a bit off Cleveland Avenue in Atlanta, Georgia along with a chicken coop, a garden, and a small concrete pool I could swim in during summer visits. Those bees were very gentle, but like most of America’s honeybees in that era, they didn’t stand a chance against the varroa mite. Once his hives succumbed to the mite, he gave up on them.
Nowadays he has little interest for hobbies, but occasionally I’ll see a spark of interest when I bring up beekeeping with him. In some ways beekeeping is a link to my past. It is also a potential link to my family in the future, but that remains to be seen.
A few years ago, my wife and I adopted two boys from the foster care system. Because so much was in flux, I moved the bees from the backyard to my family farm so I could install a playground. I opted to build it myself and have them help for many reasons.
I designed and built this from scratch for my kids. Be amazed.
My kids are a bit older now, and they don’t use it anymore. So, last summer when my folks were struggling keeping up the hives, I decided to bring the hives home again and rebuild my apiary in the back yard.
Back on Social Media
I created my LLC in 2012, but due to the kids had to put it on hold to do the important things required of a new parent. I have an account on Twitter and Facebook (I’d appreciate page likes and follows, please). However, I have been slowly getting back into the “beesness,” and my engagements with fellow beekeepers—particularly those in the U.K.—got my gears turning and led to many a long sleepless night.
Thinking Differently
I attended the Young Harris Beekeeping Institute each year back then, and I highly recommend it for beekeepers of any level. The amount of knowledge shared at that event is astounding, and you’re sure to go away with your head full of knowledge. One year, I attended a seminar by Dr. Thomas Seeley on beelining and his explorations of the forest by his residence. I remember him saying that bees in nature aren’t dying off, and that when left to their own devices, they’re doing quite well.
Now there’s something to think about: Unmanaged honeybee colonies are thriving without assistance from acaricides, pollen substitutes, sugar syrup, and the like. Yet, as beginning beekeepers, we’re told quite the different tale. “Bees are dying out!” “Save the bees!” And it’s true… for managed hives. The latest losses of beekeepers in the U.S. measure a whopping 45.5%. Let that sink in for a minute – beekeepers are losing almost 50% of their hives while natural hives are doing just fine.
The primary cause of losses is thought to be the varroa mite, and this has driven bee breeders to selectively breed bees that have varroa-sensitive hygienic (VSH) qualities. New beekeepers and old ones alike believe colonies must consistently be treated for mites, but very few beekeepers go to the trouble to develop, understand, and monitor proper thresholds for treatment. Furthermore, the treatment of bees known to not have VSH qualities, such as the Italian, only promotes poor genetics and increases the reliance on chemicals to maintain stock. This is unsustainable beekeeping at its worst.
Could the answer to most of honeybee health problems stem from the microclimate in the hives, themselves? With the introduction of varroa into the U.S. honeybee population, feral and managed, I think we’re further down the road to mite-resistant bees than many realize.
I studied bee trees and drawings Dr. Seeley created when he felled trees, cut them open, and measured and documented their configurations. I also started looking at what people like 18Bees were doing with logs and began examining them from a microclimate perspective. That led me to some interesting thoughts and ideas about temperature, thermal mass, insulation, heat gain/loss, humidity, and small, controlled entrances.
Honeybees Need a Stable Microclimate
As humans, we have temperature and humidity preferences. We generally like it about 70/21° F/C and about 45% relative humidity. When we get into crowded conference rooms the humidity and the temperature rise, we perceive the room as stuffy and become uncomfortable.
The honeybee has different parameters for their microclimate, and the most optimal ranges for brood development and production is 94.1/34.5° F/C and a RH of 90-95%. Notice the term “microclimate.” This is very important for the superorganism that is a honeybee colony. A microclimate is a climate that is very different from the climate surrounding it. In this case, the ideal conditions for a honeybee hive are quite different from the ambient temperatures surrounding it. Even in the South, it is incredibly rare and of short duration that the perfect combination of temperature and humidity exists.
Why It Matters
The honeybee is sensitive to temperature changes as little as 0.2° C, and while I’m not aware of any studies showing their sensitivity to humidity, we can assume it likely exists since they not only actively maintain humidity in their hive, but also know how to use it to maintain temperature. Consistent conditions at the correct levels yield healthier bees. Furthermore, consistent conditions that are energy efficient increase the colony’s productivity. Are wooden hives conducive to these requirements? The answer is no, but why is that the case?
The Model – The Bee Tree
When we look at the bee tree, we typically see walls that are several inches thick, cylindrical cavities, and small, easily defended entrances towards the bottom of the cavity. The thermodynamics of a bee tree are in stark contrast to standard wooden hives. Tree cavities exist in partial or mostly shade in the summer and typically full sun during the winter due to foliage. The walls of bee trees average 6” (250mm) thick, having an insulation value of ~R6 (1.06 RSI), and additionally have a property called thermal mass which provides insulation-like protection from heat gains/losses. There is rarely any upper ventilation, and when there is, bees tend to close them off with propolis in the fall. The bottom entrance is typically just above the floor, and this is due to how tree cavities are formed from old branches rotting off.
Furthermore, bee trees tend to have detritus in the bottoms that host a smorgasbord of life that is part of the environment of the honeybee colony. As you can imagine, this is quite different from typical wooden hives with thin walls that have no ability to reduce heat gain/loss, large bottom entrances, screened bottom boards, and upper ventilation. As if that wasn’t enough for the honeybee to overcome, we stick the hives in full sun to control the small hive beetle populations. Sure, full sun keeps small hive beetles at bay, but it also creates stress for the honeybee.
Typical Hive Placement and Configuration
As we stated earlier, the wooden hives have an almost endless number of configurations, so I’m attempting to describe the most common setup.
Hives with a mixture of screened bottom boards, solid and ventilated covers
We start with a wooden box, usually of the Langstroth design in the U.S. (though his original design was a good bit different than what we have today), with a bottom board and a lid. Due in large part to the influx of varroa in 1987, many beekeepers transitioned to screened bottom boards (they were in use well before this time). The idea was that varroa mites could fall to the ground as they fell off bees. Along comes the small hive beetle in 1998, and subsequent control measures include more acaricides as well as full sun were put into place.
As a result of full sun and thin-walled hive bodies, solar heat gain during summer months becomes incredible. Bees must move outside the hive and beard to keep the brood chamber from overheating. Imagine – the brood area is overheating (hotter than 95/35° F/C!) and the bees move outside to prevent harming themselves. Some beekeepers noticed this, and now the typical setup includes a ventilated lid of some sort. This ventilated lid creates a chimney effect – the warm, humid air rises and escapes through the upper vent and is replaced with cooler, drier air through the bottom entrance and/or screened bottom board. During the winter, these full sun locations offer little protection against the wind, which sharply increases heat loss rates. The fact honeybees survive despite these conditions fills me with awe!
Pest Invasions and Temperament
Another side effect of screened bottom boards and ventilated lids is the weakened physical defenses of a beehive. In contrast with what we typically find in nature and in addition to large bottom entrances, we have now introduced a large area on the bottom of the hive for ants to infiltrate. Because of the chimney effect most of the hive scent is carried out the ventilated cover where small hive beetles and ants can gain entry without much challenge from guard bees. This weakened physical structure results in more guard bees being recruited, which increases the defensiveness and perceived aggression of a hive. Think about how many hives you’ve had and called them cranky or aggressive and ask yourself if you inspected their environment to see why.
Heat Loss and Gain
Log cabins and bee trees provide stable microclimates through thermal mass. Even though wood has an R value of ~1.4 per inch (.25 RSI per 25mm), when it is thick it behaves differently. During the daytime, it absorbs sunlight, and at night it slowly discharges that heat, providing an energy efficient internal area that can be maintained with less fuel consumption. However, ¾” (19mm) wood has an R value of 1.05 (.18 RSI) and no thermal mass to speak of. The effect is a box that acts like a convection oven during the day and a refrigerator at night. Why? Heat moves towards cold in all directions, not just upward, and during the daytime. These large swings in temperature make the lives of bees more energy intensive as they’re trying to cool the hive during the day and heat it at night.
Two hives, side by side in direct sunlight and their solar heat gain and loss on a mild winter day. The Test Hive is our patent pending design.
Same Hives in Summer - 7 Day comparison. You can tell the sunny days by the larger spikes in Temperature on the Lang Hive
Another impact of large temperature swings on a hive is bees recruited for fanning. Dr. Chelsea Cook performed this research and concluded that the faster the temperature rises, the more bees were recruited for cooling the hive through fanning. Larger numbers of bees recruited for cooling activities represent a loss in productivity and an increase in food consumption for energy needs.
To put it in human terms, imagine a house with only plywood walls, a front door that was open, no windows, and a solid roof sitting in full sun. If you’ve ever0 been in a shed, you know how miserable that feels – super hot in the summer and super cold in the winter. We then take the floor out and replace it with a screen. Next, we punch a hole in the roof so hot air can escape (chimney effect). Well, that’s a little better, but it’ll still be hot in the day and cold at night. During the winter it’ll basically be cold all the time, and you’ll spend a fortune on your electric or gas bill trying to regulate the temperature and humidity.
Now imagine the bees as the air conditioner and furnace. Imagine how much fuel they consume in the activity of regulating hive conditions they’ve evolved to require while inhabiting a house with thin walls, massive solar heat gain during the day, heat being sapped away at night, no floor, an open door, and a hole in the roof. And we wonder why they’re always at the neighbor’s pool in the summer getting water. You’d be at there too if you lived like this.
But Wait, There’s More!
Condensation. Every beekeeper worries about it in the winter and rightfully so. Nothing kills a colony faster than cold water dripping onto a cluster of bees. They’re hearty enough to survive the cold, but they simply cannot sustain cold water dripping on them while doing it. To prevent condensation, what did we do? You guessed it, we ventilated the hive at the top. This solves the problem of condensation, but it creates another problem – energy loss. And it is substantial.
Think about your body when it gets cold. It triggers an instinct in the muscles to shiver. The bees do this as well with their wing muscles, and in a small cluster, they are able to keep the internal temperature at 95/35° F/C. As they do this, they also generate water vapor, but remember that the creation of water vapor requires a large amount of energy. Let’s get an idea of how energetically expensive this process is.
According to Derek Mitchell, “It takes 0.67kWh per kg to evaporate water at 40°C. That means 20kWh of energy to make 30kg water at 40°C change into vapour.” If we convert .67 kWh to calories we arrive at 576481.8355 calories (or 576.48 kilocalories) required to convert 1kg (2.2 lbs) of water to vapor. This process is required from the bees to maintain brood nest humidity and cure honey, and it is extraordinarily expensive. To present an idea on how expensive this is, one cup of honey contains 1,031 kilocalories and is equal to the amount of energy a human consumes when running for 82 minutes! 576.48 kilocalories represent over 1/2 cup of honey, which is ~.19kg (.41 lbs).
This amount of energy could sustain human running for over 30 minutes! Think about that, a half cup of honey is enough energy to run a 5k in 30 minutes. We need to see it in these terms because a 1/2 cup of honey to us may seem inconsequential. However, if we assume nectar is 80% water, then every 1kg (2.2 lbs) of nectar yields .2kg (.44 lbs) of honey and requires a 1/2 cup of honey (not nectar) to fuel the dehumidification. The bees do this all day, every day, and we let all that thermal energy escape through a hole in the roof.
Evaporation is a cooling mechanism and condensation is a warming mechanism. In other words, evaporation carries away heat in the form of water vapor, while condensation releases that heat in the form of dry air. According to this site, “In the case of condensation, again one speaks of latent heat, since the heat to be released during condensation is not directly evidenced by a change in temperature (from the Latin word latere, which means “to be hidden” or “not to appear directly”). In the case of water, the latent heat to be released during condensation is 2257 kJ per kilogram. This is more than five times the amount of heat that would have been required to heat the water from 0 °C to 100 °C! This explains, for example, why steam burns are more dangerous than water burns.”
Latent heat can be thought of like this: Water exists at 32/0° F/C in a liquid or a solid state. The temperature of 32/0° ice is the same as that of 32/0° water. The difference is latent heat, or the energy required to get 32/0° ice to change states to water. The honeybee is better served when the energy released through condensation is retained inside the hive.
I am convinced our current methods are little more than a duct tape upon duct tape approach. The original problem was the inability of the hive to sustain proper conditions for the honeybees and, man being man, approaches the problem with manmade solutions not found in nature. Instead of fixing the design issue, we kept addressing symptoms, which has resulted in an almost complete loss of the ability of the honeybee to regulate its environment. It’s basically death by a thousand papercuts, and we wonder why we have such astronomical colony losses year after year.
It Is Time for a Better Hive
We need a new hive, one that is modular like the Langstroth hive and provides a suitable cavity that bees can use to regulate their microclimate with ease. It needs to reduce energy loss to a level low enough to be considered energy efficient and offer the colony a proper physical defense against pests. It should allow the bees to enjoy the climate they’ve evolved to rely on while providing the beekeeper with the ability to easily manipulate and manage their colonies. It should provide bees with the proper humidity levels needed to keep varroa in check and allow for timely curing of honey.
I believe I have done it. More to come…
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