Article by Corwin Bell
Insulation Panels on a Bee Hive for Winter
(Photo credit: Karen Sadenwater)

In regions that have big fluctuations in temperatures during the winter months, it is optimum to insulate bee hives. In Colorado we have experimented for many years by insulating half of our hives and on the other half not using any insulation. What we found is that if the bees have sufficient honey stores, insulating the hives does not increase the overwintering abilities of the bees.

With this said, we have also found that insulating hives has two important effects. First, if a hive has marginal honey stores, insulating greatly increases its chances of overwintering. Secondly, because the bees create warmth by eating honey and using this fuel to generate heat by flexing their wing muscles, a hive

that is insulated will have many more honey combs to harvest in the spring. The thermal mass of the honeycombs greatly reduces the fluctuation of the nest temperature because the honeycombs act like "thermal batteries" and can store heat during the day and gradually release it at night. The insulation panels substantially add to this effect by buffering both hot and cold outside temperatures.


Dangerous weather anomalies
The insulation panels also help balance out the ever increasing weather anomalies we are experiencing. The most dangerous weather anomaly for the bees is when there are several unusually hot days in the fall and the bees have collected water to cool the hive, only to have the temperature suddenly plummet to freezing in a single day. This situation leaves the bees with moisture in the hive and no way of fanning that moisture out. The insulation panels will help keep the hive at a more consistent temperature, which is beneficial when the temperatures fluctuate from a temperature like 60 degrees down to 25 degrees in a day.


 Honey Bee_nest_cottonwood_tree_cavity
(Photo credit: Corwin Bell)
Bees living inside a hollow of a cottonwood tree! We have seen bees in this tree for the last 12 years, it's amazing!

When insulating a hive we want to simulate what the bees experience in nature when living inside a hollow of a tree. Our design criteria for the creation of the insulation panels was to mimic, as closely as possible, the hive nest of bees in the wild. Bees generally select nests in deciduous trees of a particular diameter and thickness. The trees that best match the bee's criteria is the cottonwood tree. Having observed many wild bee hives in trees and rescued several bees nests that have been cut down, I found that there is typically at least a thickness of four inches of wood surrounding the nest.

The R-value for wood ranges between 1.41 per inch (2.54 cm) for most softwoods and 0.71 for most hardwoods (R-value is a measure of insulating ability of a material or
thermal conductivity ). Cottonwood is a soft wood, so if you calculate the insulating ability of cottonwood at four inches, you get an R-value of 5.6. The 1 inch thick blue board insulation that is inset into our winterizing panels has a R-value of 5.0 . If you add the thickness of the pine wood of the hive itself, you can add an R-value of .71 to the insulation panels making a total R-Value of  5.71. So you can see that the panels are like bundling up your hive for winter in a big cottonwood tree, just like... well almost like what nature intended!

(Photo credit: Corwin Bell)
How cool is this? A top bar demo hive inset at Brook Levine's apiary at Sustainable Settings in Carbondale, CO

How about using straw bales set around the hive in the winter?
Well, kind of a good idea, but there are some big issues. The biggest problem with straw bales is keeping them dry. As soon as the straw gets wet, there are mold issues and a hive surrounded by moldy straw bales is not a good idea. The second problem is that the bales attract mice and by the time spring rolls around the bales are usually full of mice. So one better have a mouse guard on their hive for the winter.

 Straw Bales Insulating a Top Bar Hive
Straw Bales - not such a good idea, the bales mold and attract mice
Mouse Guard on Bee HIve
Mouse Guard on bee Hive - 1/4" hardware cloth staples over the entrance so bees can get in and out but mice can not.

Does using insulation heat up my hive?
Insulation does not heat up the hive, it insulates inside temperatures from outside temperatures.

Because the bees generate heat by flexing their wing muscles, they are the heater. If we were in a tent that had no insulation a heater would be pretty useless in sub-zero or cold temperatures. Say we put the same heater in a cabin with great insulation, we would probably have to turn off the heater shortly because we would "capture" the heat within the dwelling due to the insulation keeping the “heat” or warmth inside the cabin.

Same with cooling, the bees are cooling their hive with water vapor and fanning their wings, i.e. creating "air conditioning". This is the same principle as air conditioning in our modern homes that are insulated. If we put an air conditioner in a tent with no insulation on a hot day we would have to run the air conditioner on high all day to keep the temperature comfortable. If we put big panels of insulation around the tent, now we have insulated the inside cool air from the outside hot air, so the less we have to run the air conditioner.

Warm winter days will not overheat the hive. If it is cold out, it will get colder in the hive and the bees will warm the hive. The insulation helps keep in this warmth. If it is cold weather for several days or weeks and then the temperatures suddenly warm up and the sun is out beating down on the hive, the insulation will keep the hive from getting too warm. And in the winter when the days are shorter by the time it warms up a bit it is already starting to cool down.

In cold climates like Colorado you can keep the insulation panels on from October through March, as we sometimes still get temperature drops and snow in March (sometimes into April).

The insulation piece that fits between the lid and the roof of the hive can be kept on all year long. In the summer this helps insulate the hive from the hot temperatures. Just as insulation in an attic of house works.


What is included in the winterizing hive package?

 Top Bar Hive Insualtion Panels Winterizing a Bee Hive
(Photo credit: Karen Sadenwater)

The Insulation Panel kit includes 2 sides panels, 2 end panels and a large piece of insulation that fits between the lid and the roof of your hive. Bungee cord holds the insulation panels snug against the hive. You will take off the window cover and hardware of the hive and store it until spring. See our video on putting on the


Related Articles:

In our 
Winterizing and Insulating Your Bee Hive read more about winterizing your hive, moving the falseback forward, accessing the honey stores and when to put on the insulation panels.

In our Harvesting Honey from a Top Bar Hive article last month, learn more about thermal mass and how the bees use combs of honey as fuel to create thermal heat.

More cool pictures of bee hives!
Bee Nest in a Cottonwood tree
(Photo credit: Corwin Bell)
Bee nest inside a tree hollow

Wild Bee Nest in Tree and the Clever Cover
(Photo credit: Corwin Bell)
Brook's clever idea to cover up the hole in the tree! As good a use for a pie pan as any!

Top Bar Hive inset into a Log
(Photo credit: Corwin Bell)
Semi Wild Bees! Another one of Brook's Top Bar Hives inset into a cottonwood log

Top Bar Hives at Sustainable Settings in Carbondale, CO

(Photo credit: Corwin Bell)
And finally the modern top bar hive. It just need insulation panels!
Brook's full apiary of Top Bar Hives at Sustainable Settings in Carbondale, CO

And some wild bees in trees!

 Bees going into a Tree Hollow
(Photo credit
: Corwin Bell)
Bees living inside a cottonwood tree hollow


Bees inside a cottonwood tree hollow
(Photo credit: Corwin Bell)
It can bee hard to spot wild bees in a tree when out for a hike. The key is to look towards the sun to spot the tiny flashes of bees buzzing into the hole.

There are bees in this tree learn how to spot them
(Photo credit: Corwin Bell)
This is the tree that has the wild bees inside. Just passing by you might miss them but look for the old cottonwood trees that are more likely to have a hollow cavity inside.